牦牛粪维系青藏高原高寒草地健康的作用机制
摘要
青藏高原高寒草地是我国重要的牧区之一,也是广大藏族同胞赖以生存的基础。其生态系统的稳定不仅对我国东部和西南部气候产生巨大影响,而且对北半球甚至全球的气候产生显著影响。然而,日趋严重的草地退化问题已给青藏高原及其周边地区的生态环境和社会经济的可持续发展构成了严重威胁。
在青藏高原,牦牛粪常作为牧民生活最依赖的燃料从草地上被捡走后,燃烧牦牛粪使灌丛草地免于砍伐;同时,致使高寒草地损失了养分、种子。关于牦牛粪对高寒草地的健康是否具有维系作用,未见报道。为此,本文系统地研究了如下内容:1)调查青藏高原牧区牧民燃烧的牛粪总量,客观评价燃烧牛粪能使多大面积的灌丛草地免于砍伐和破坏,量化其草地生态系统因牦牛粪被捡走而流失的养分;2)牦牛粪的堆积对青藏高原高寒草地生态系统的影响;3)观测牦牛的排粪特性,研究牦牛和绵羊的消化率特性,量化多少头牦牛产生的粪可满足每人每年的需要量;4)研究牦牛和绵羊对高寒草地牧草种子的消化道传播机制与过程,以及其经过消化道后的萌发情况;5)放牧牦牛和绵羊对青藏高原高寒草地的影响。得出了如下主要结果:
4月底牦牛粪含水量为75%,全氮、全磷、全钾和有机质含量分别为1.33%、0.159%、0.626%和51.8%,pH为6.84。在天祝高寒草地上,牦牛粪堆积一年后,牦牛粪仍然完好的存在于草地上。牦牛粪的堆积有利于高寒草地土壤物理性质的改善,能显著降低土壤容重和增大土壤含水量。牦牛粪的堆积增加了牛粪下面和距牛粪堆10cm远土壤的速效氮、全氮、速效磷、全磷、速效钾和有机质含量。
在牦牛粪堆积的当年,牛粪堆积并未促进周围植物的生长;在次年,促进了周围植物的生长。堆积一年5个月后,粪堆下面植物仍然枯死;牦牛粪旁边10 cm的总产草显著高于距离牛粪50cm处的对照。牦牛粪覆盖草地的第一、二年,覆盖造成产草量的降低。
牦牛粪的热值为15.38～17.89 KJ/g,其平均值为16.47 KJ/g。在供试的21种灌木的热值,为17.80～24.26 KJ/g,其平均值为21.22 KJ/g。甘肃省天祝县抓喜秀龙乡、甘肃省肃南县皇城镇、青海省玛沁县大武镇和西藏自治区那曲古露镇4地,牧民平均每人每年的牛粪燃烧量分别为2182、590、9233和3595kg,上述4地平均每人每年因燃烧牦牛粪而减少砍伐的灌木量分别为1702、460、7202和2804kg或面积为1229、332、5200和2025 m2的灌木。
天祝高寒草地全年放牧的牦牛,粪中的全磷、全氮、全钾和有机碳含量分别为0.4974 %、2.031 %、0.665 %和39.41 %。天祝高寒草地全年放牧的绵羊,粪中的全磷、全氮、全钾和有机碳含量分别为0.5026 %、1.954 %、0.707 %和41.14 %。由于燃烧牦牛粪,上述4地区牧民平均每人每年燃烧损失的P为11、3、46和18 kg,N为44、12、188和73 kg,K为15、4、61和24 kg。
在天祝高寒草地,综合全年的排粪特性,整群牦牛的排粪干重平均为2.0 kg/d·头。5.2头、1.5头、12.7头和5.0头牦牛,分别可满足上述4地区牧民平均每人燃烧牛粪的需要。
4月底,天祝县抓喜秀龙乡,草地上放牧牦牛7 h 30 min,草地上放牧占全天时间的31.25%;草地上排粪占全天总量的35.65%。按整群牦牛计算,平均每头牦牛排粪覆盖面积为0.194 m2,其中平均排粪覆盖草地面积约0.078 m2/ d·头。
牦牛在10月份和2月份对混合草的表观消化率分别为63.22%和61.81%,1月份对青稞秸秆的表观消化率为61.81%,4月份对燕麦青干草的表观消化率为59.42%。绵羊在10月份和2月份对混合草的表观消化率分别为57.64%和53.68%,1月份和4月份对燕麦青干草的表观消化率分别为57.25%和55.18%。
种子经过牦牛和绵羊消化道后的回收率因家畜和植物种类不同而异。经过牦牛消化道后回收率大于20%的为黄花棘豆、马蔺、珠芽蓼、珠芽、皱叶酸模、披针叶黄华、狼毒、阴山扁蓿豆、醉马草、双柱头藨草、密花香薷、灰绿藜、镰形棘豆、华扁穗草、水葱、红棕苔草、无脉苔草、轮叶马先蒿、多茎委陵菜和车前;回收率小于1%的为溪畔银莲花和红花岩黄芪;回收率在1%～10%范围内的为垂穗披碱草、铁棒槌、迷果芹、高山韭、糙毛鹅冠草、线叶嵩草、窄果苔草、无芒雀麦、紫羊茅和赖草;回收率在10%～20%的为青藏苔草和砂生槐。
经过绵羊消化道后种子回收率大于20%的为黄花棘豆、披针叶黄华和镰形棘豆;回收率小于1%的为垂穗披碱草、铁棒槌、迷果芹、糙毛鹅冠草、红花岩黄芪、溪畔银莲花、无芒雀麦和紫羊茅;回收率在1%～10%范围内的为青藏苔草、马蔺、珠芽蓼、珠芽、皱叶酸模、狼毒、高山韭、线叶嵩草、醉马草和砂生槐;回收率在10%～20%的为无脉苔草、扁蓿豆、轮叶马先蒿、双柱头藨草、密花香薷、灰绿藜、华扁穗草、水葱、红棕苔草和车前。
种子经过牦牛和绵羊消化道后,发芽率升高的有无脉苔草、红棕苔草、镰形棘豆和灰绿藜和双柱头藨草;经过牦牛消化道后种子发芽率提高而经绵羊消化道未提高的有珠芽蓼、线叶嵩草和华扁穗草;发芽率明显降低的有禾草、黄花棘豆、皱叶酸模、铁棒槌、迷果芹、高山韭、轮叶马先蒿、披针叶黄华、密花香薷和车前,保持不变的有青藏苔草、马蔺、珠芽、狼毒、砂生槐、阴山扁蓿豆和水葱。
在天祝高寒草地11～4月份的牦牛粪中,共鉴定出43种植物,平均每块牦牛粪中的种子数为45粒。
通过2008年和2009年连续两年的研究,在中度放牧牦牛、中度放牧绵羊、中度牦牛绵羊混合放牧的3块放牧强度相近的样地中,单纯放牧绵羊草地的产草量明显高于牛羊混合放牧和单纯放牧牦牛的草地,而牛羊混合放牧草地的产草量也明显高于单纯放牧牦牛的草地。相似的结果还表现在植物高度、枝条总密度上。中度放牧绵羊、中度牦牛绵羊混合放牧、中度放牧牦牛的3样地产草量分别为581 g/m2、476 g/m2、411g/m2。
中度放牧绵羊的草地植被群落的Shanno-Wiener多样性指数为4.5825,明显低于中度放牧牛羊和中度放牧牦牛的草地;牛羊混合放牧草地,在中度放牧下植被群落的Shanno-Wiener多样性指数最大,重度放牧下最小。中度放牧牦牛草地上植物种数多于中度放牧牛羊和中度放牧绵羊草地。混合放牧牛羊草地,中度放牧条件下物种数最大,重度放牧条件下最小。中度放牧牦牛草地Pielou均匀性指数最高,其次为中度放牧牛羊、中度放牧绵羊。
中度放牧绵羊草地土壤较为松软,中度放牧牦牛草地土壤紧实度较高,中度放牧牛羊草地居于二者之间。土壤速效钾、速效氮、速效磷、全氮、全磷含量最高为中度放牧绵羊草地,其次为中度放牧牛羊草地,最低为中度放牧牦牛草地。土壤有机质含量为中度放牧羊草地显著高于中度放牧牛羊和中度放牧牦牛草地,而中度放牧牛羊草地低于中度放牧牦牛草地,但差异不显著。中度放牧绵羊草地土壤中性磷酸酶、过氧化氢酶和土壤尿酶活性均高于中度放牧牛羊、中度放牧牦牛草地。除0～10cm土壤尿酶活性外,中度放牧牛羊草地土壤中性磷酸酶、过氧化氢酶和土壤尿酶活性均高于中度放牧牦牛草地。
综上所述,在青藏高原高寒草地上,燃烧牦牛粪使灌丛草地免于砍伐,间接地保护了灌丛草地。冷季牦牛粪的堆积造成至少2年产草量的降低,而牦牛粪的捡走减轻了牛粪堆积对草地的危害。由于牦牛粪中含有较多的N、P、K等养分和可萌发的种子,因此捡走牦牛粪引起草地生态系统中养分和种子的流失,且这种流失作用随着放牧强度的增大呈增加趋势,这使牦牛粪对青藏高原高寒草地健康的维系作用弱化。在草地上将牦牛粪进行破碎化处理,或进行堆肥后归还草地,方可解决牛粪堆积与捡走牛粪的矛盾,使牦牛粪对青藏高原高寒草地健康的维系作用得以保持。由于牦牛粪绝大多数被捡走,而绵羊粪绝大多数留在草地上,这是导致放牧绵羊更有益于青藏高原高寒草地健康的部分原因。基于上述研究,本文提出了“多绵羊少牦牛”高寒草地放牧畜牧业经营管理模式。
Alpine grassland on Tibetan plateau is one of important pastoral areas in China and is the general basis for the survival of Tibetan people. The stability of alpine grassland ecosystem has enormous impact on the climate of Eastern and Southwestern China, but also has a significant impact on the climate of northern hemisphere, even the world's climate. However, the increasingly serious problem of grassland degradation has posed a serious threat on the Tibetan Plateau even surrounding area’s ecological environment and socio-economic sustainable development.
On Tibet Plateau, yak dung was collected from the alpine grassland to fuel and was herders’reliable fuel fueled for cooking, making tea and warming. Collecting dung lead to nutrients and seeds decrease in alpine grassland, but burning yak dung reduced bush logging in the shrub grassland. In fact, it has protected the shrub grassland by fueling the yak dung. The yak dung has the role of maintenance for Qinghai-Tibet Plateau alpine grassland health, which has not been reported in literature. So a series experimental tests were studied systematically which included: 1) investigating the total volume of cow dung systematically fueled by herders in Tibetan plateau pasturing area, study how much areas shrub grassland is protected from damage and destruction with fueling yak dung by investigating yak dung amount fueled and testing calorific value of yank dung and shrubs, quantizing how much grassland ecosystem nutrients were lost by collecting yak dung; 2) the influence of yak dung accumulation on alpine grassland ecosystem by artificial accumulated yak dung on alpine grassland; 3) observing the defecation characteristics of yak, studying the digestibility characteristics of yak and sheep, quantizing how much cow dung needed one person per year as fuel; 4) the mechanism and process of endozoochorous seed dispersal by yak and sheep in Tianzhu alpine grassland on alpine grassland seeds, and whether the seeds defecated by yak and sheep are easily germinating; 5) the influence of grazing system which grazing yaks and sheep only and mixed on grassland soil, species biodiversity and forage product. The main results obtained are as followed.
Moisture content of the yak dung applied for accumulation experiment was 75%. Total N, P and K was 1.33%, 0.159% and 0.626%, total organic matter was 51.87%, pH was 6.84. Dung was still present in the field after one year’accumulation. Yak dung (treatment) decreased soil pH, increased soil EC, improved soil physical properties of alpine meadow, reduced soil bulk density and increased soil moisture significantly. The accumulation of the yak dung increased the available N, total N, available P, total P, available K and organic matter content of soil under yak dung and around dung 10 cm.
Yak dung accumulation caused above-ground plants death under dung for poor oxygen content and less light in the first year. After yak dung accumulating one year and five months, total forage product around dung 10 cm was significantly higher than the control. For yak dung patch overlapped plants and caused the death of forage, its accumulation caused forage product decline. It is a dilemma that moving down yak dung from alpine grassland made soil nutrient and soil seed losses while accumulation made forage production decreased.
The calorific value of yak dung ranged from 15.38 to 17.89 KJ / g, and the average is 16.47 KJ / g. Among 21 species shrubs tested, the calorific value ranged from 17.80 to 24.26 KJ / g, and the average is 21.22 KJ / g. The average volume of yak dung fueled annual each herdsman in Zhuaxixiulong Township of Tianzhu County in Gansu Province, Huangcheng Township of Sunan County in Gansu Province, Dawu Township of Maqin County in Qinghai Province and Gulu
Township of Naqu County in Tibet was 2182 kg, 590 kg, 9233 kg and 3595 kg, respectively. The average volume of shrub yields which are reduced by fueling yak dung in the four places were 1702, 460, 7202 and 2804 kg or area equivalent 1229, 332, 5200 and 2025 m2.
The monthly average of total phosphorus, total nitrogen, total potassium and total organic carbon content in yak dung is 0.4974%, 2.031%, 0.665% and 39.41%, while which in sheep dung is 0.5026 %, 1.954 %, 0.707 % and 41.14 %, respectively. Approximately, 11, 3, 46 and 18 kg P, 44, 12, 188 and 73 kg N, 15, 4, 61 and 24 kg K was fueled each herdsman annually in four places mentioned frontly, respectively.
Integrating the defecation volume of whole year, the annual defecation amount of yak in cluster was 2.0 kg / d ? head. So, 5.2, 1.5, 12.7 and 5.0 yaks can meet herder's yak dung needs for four places mentioned frontly, respectively.
At the end of April, in Zhaxixiulong Township of Tianzhu County, grazing time on the grassland is 7 hours and 30 minutes. The proportion of dung weight defecated on the grassland was 35.65 percent. According to whole group of yaks defecation, total occupation area was per yak defecated was 0.194m2, and grassland area covered by each yak’s defecation per day was about 0.078 m2.
Yak apparent digestibility of mixed-grass in October and February was 63.22 % and 61.81%, of highland barley straw in January was 61.81%, and of oat hay in April was 59.42%. Sheep apparent digestibility of mixed grass in October and February was 53.68% and 57.64%, of oat hay in January and April were 57.25% and 55.18%.
Recoverage proportion of alpine grassland plant seeds defecated by yak and sheep was different by animal and species. Oxytropis ochrocephala, Iris lacteal, Polygonum viviparnm, Rumex crispus, Thermopsis lanceolata, Stellera chamaejasme, Pocockia ruthenia, Achnatherum inebrians, Scirpus distigmaticus, Elsholtzia densa, Chenopodium glaucum, O. falcate, Blysmus sinocompressus, Scirpus validus, Carex przewalski, C. enervis, Pedicularis verticillata, P. multicaulis, Plantago asiatica seeds and bulbil of P. viviparnm recoverage propoion fefacated by yak was greater than 20 percent; Anemone rivularis and Hedysarum multifugum seeds recoverage propoion was smaller than one percent; Elymus nutans, Aconitum szechenyianum, Sphallerocarpus gracilis, Allium sikkimense, Roegneria hirsute, Kobresia capillifolia, C. angustifructus, Bromus inermis, Festuca ruba and Leymus secalinum seeds recoverage propoion was range from 1 to 10 percent; and C. moorcroftii and Sophora moocroftiana seeds recoverage proportion was range from 10 to 20 percent.
O. ochrocephala, T. lanceolate and O. falcata seeds recoverage propoion fefacated by sheep was greater than 20 percent, E. nutans, A. szechenyianum, S. gracilis, R. hirsute, H. multifugum, A. rivularis, B. inermis and F. ruba seeds recoverage propoion was smaller than one percent, and C. moorcroftii, I. lacteal, R. crispus, S. chamaejasme, A. sikkimense, K. capillifolia, A. inebrians, S. moocroftiana and P. viviparnm seeds and Bulbil of P. viviparnm seeds recoverage propoion was range from 1 to 10 percent, C. enervis, P. ruthenia, P. verticillata, S. distigmaticus, E. densa, C. glaucum, B. sinocompressus, S. validus, C. przewalski and P. asiatica seeds recoverage proportion was range from 10 to 20 percent.
Seed of C. enervis, C. przewalski, O. falcate, C. glaucum and S. distigmaticus defecated by yak and sheep germination was promoted. P. viviparnm, K. capillifolia and B. sinocompressus seeds germination was promoted passed yak’s digestive tract but that was not passed sheep’s’. Grasses, O. ochrocephala, R. crispus, A. szechenyianum, A. sikkimense, P. verticillata, T. lanceolata, E. densa and P. asiatica seeds germination was reduced, and seeds of C. moorcroftii, I. lacteal, S. chamaejasme, S. moocroftiana, P. ruthenia and S. Validus seeds, and P. viviparnm bulbil germination was unchanged.
There are 43 species identified in yak dung from Nov. to April, and there are 45 grain seeds per piece of yak dung.
In three grassland plots grazed with similar intensity including grazing yak moderately, and grazing sheep moderately, whether in 2008 or 2009, the forage yield of plot only grazing sheep was higher than the remaining two, and which of grazing yak and sheep was higher than the plot grazing yak he yak The average forage yield of 2008 and 2009 on grazing sheep only, yak and sheep, and only yak is 581, 476 and 411 g/m2, respectively. Similar results were appeared in plant height and total shoot density.
The Shannon-Wiener diversity index of the grassland grazing sheep moderately is 4.5825, lower than that of grazing yak and sheep moderately and that of grazing yak moderately, of grazing yak. Similar result appeared in Pielou evenness index .The biggest Shannon-Wiener diversity index appeared on moderate grazing plot and smallest appeared on heavy grazing plot in mixed grazing with yak and sheep plots. Species numbers of the grassland grazing yak moderately is more than mixed grazing moderately plot with yak and sheep and grazing sheep moderately. Yak and sheep mixed rangeland, the species number increased firstly, and then decreased as grazing intensity increasing, that is, under moderate grazing the species number was highest.
Soil bulk density in plot with grazing sheep moderately was smaller than grazing mixed with yak and sheep, the biggest was the grassland grazing yak moderately. Opposite result appeared in soil available potassium, available nitrogen, available phosphorus, total nitrogen and total phosphorus content. Soil organic matter content in grazing sheep moderately is significantly higher than that of grazing mixed with yak and sheep and grazing yak moderately, while which of grazing yak moderately is higher than that grazing mixed with yak and sheep.
Soil neutral phosphatase, catalase and urease enzyme activity in plot with grazing sheep moderately was higher than grazing mixed with yak and sheep, the smallest was the grassland grazing yak moderately except soil urease enzyme activity form 0 to 10 cm.
On Tibet Plateau alpine grassland, burning yak dung reduced bush logging, so it has protected the shrub grassland by fueling the yak dung. For accumulation of yak dung defecated in cold season on alpine grassland led to forage product decline at least two years while removed yak dung from alpine grassland made the harm caused by yak dung accumulation eliminated. As there are lots of N, P, K and other components and some germinable seeds in yak dung defecated in cold season, so collecting dung lead to nutrients and seeds losses in alpine grassland, and the losses increased with the growing grazing intensity. Which weakened the maintenance of yak dung for Qinghai-Tibet Plateau alpine grassland health. Break down yak dung on alpine grassland or return to grassland after composting, which can resolve the dilemma that dung accumulation and removing, and maintenance of yak dung on the alpine grassland health is maintained. Most of yak dung was removed from grassland while sheep dung was keeping, which was one of reasons made grazing sheep was more benefit alpine grassland than grazing yak on Tibet Plateau. So, for above reason,“more sheep and fewer yaks”grazing livestock management mode on alpine grassland was proposed in this paper.
在青藏高原,牦牛粪常作为牧民生活最依赖的燃料从草地上被捡走后,燃烧牦牛粪使灌丛草地免于砍伐;同时,致使高寒草地损失了养分、种子。关于牦牛粪对高寒草地的健康是否具有维系作用,未见报道。为此,本文系统地研究了如下内容:1)调查青藏高原牧区牧民燃烧的牛粪总量,客观评价燃烧牛粪能使多大面积的灌丛草地免于砍伐和破坏,量化其草地生态系统因牦牛粪被捡走而流失的养分;2)牦牛粪的堆积对青藏高原高寒草地生态系统的影响;3)观测牦牛的排粪特性,研究牦牛和绵羊的消化率特性,量化多少头牦牛产生的粪可满足每人每年的需要量;4)研究牦牛和绵羊对高寒草地牧草种子的消化道传播机制与过程,以及其经过消化道后的萌发情况;5)放牧牦牛和绵羊对青藏高原高寒草地的影响。得出了如下主要结果:
4月底牦牛粪含水量为75%,全氮、全磷、全钾和有机质含量分别为1.33%、0.159%、0.626%和51.8%,pH为6.84。在天祝高寒草地上,牦牛粪堆积一年后,牦牛粪仍然完好的存在于草地上。牦牛粪的堆积有利于高寒草地土壤物理性质的改善,能显著降低土壤容重和增大土壤含水量。牦牛粪的堆积增加了牛粪下面和距牛粪堆10cm远土壤的速效氮、全氮、速效磷、全磷、速效钾和有机质含量。
在牦牛粪堆积的当年,牛粪堆积并未促进周围植物的生长;在次年,促进了周围植物的生长。堆积一年5个月后,粪堆下面植物仍然枯死;牦牛粪旁边10 cm的总产草显著高于距离牛粪50cm处的对照。牦牛粪覆盖草地的第一、二年,覆盖造成产草量的降低。
牦牛粪的热值为15.38～17.89 KJ/g,其平均值为16.47 KJ/g。在供试的21种灌木的热值,为17.80～24.26 KJ/g,其平均值为21.22 KJ/g。甘肃省天祝县抓喜秀龙乡、甘肃省肃南县皇城镇、青海省玛沁县大武镇和西藏自治区那曲古露镇4地,牧民平均每人每年的牛粪燃烧量分别为2182、590、9233和3595kg,上述4地平均每人每年因燃烧牦牛粪而减少砍伐的灌木量分别为1702、460、7202和2804kg或面积为1229、332、5200和2025 m2的灌木。
天祝高寒草地全年放牧的牦牛,粪中的全磷、全氮、全钾和有机碳含量分别为0.4974 %、2.031 %、0.665 %和39.41 %。天祝高寒草地全年放牧的绵羊,粪中的全磷、全氮、全钾和有机碳含量分别为0.5026 %、1.954 %、0.707 %和41.14 %。由于燃烧牦牛粪,上述4地区牧民平均每人每年燃烧损失的P为11、3、46和18 kg,N为44、12、188和73 kg,K为15、4、61和24 kg。
在天祝高寒草地,综合全年的排粪特性,整群牦牛的排粪干重平均为2.0 kg/d·头。5.2头、1.5头、12.7头和5.0头牦牛,分别可满足上述4地区牧民平均每人燃烧牛粪的需要。
4月底,天祝县抓喜秀龙乡,草地上放牧牦牛7 h 30 min,草地上放牧占全天时间的31.25%;草地上排粪占全天总量的35.65%。按整群牦牛计算,平均每头牦牛排粪覆盖面积为0.194 m2,其中平均排粪覆盖草地面积约0.078 m2/ d·头。
牦牛在10月份和2月份对混合草的表观消化率分别为63.22%和61.81%,1月份对青稞秸秆的表观消化率为61.81%,4月份对燕麦青干草的表观消化率为59.42%。绵羊在10月份和2月份对混合草的表观消化率分别为57.64%和53.68%,1月份和4月份对燕麦青干草的表观消化率分别为57.25%和55.18%。
种子经过牦牛和绵羊消化道后的回收率因家畜和植物种类不同而异。经过牦牛消化道后回收率大于20%的为黄花棘豆、马蔺、珠芽蓼、珠芽、皱叶酸模、披针叶黄华、狼毒、阴山扁蓿豆、醉马草、双柱头藨草、密花香薷、灰绿藜、镰形棘豆、华扁穗草、水葱、红棕苔草、无脉苔草、轮叶马先蒿、多茎委陵菜和车前;回收率小于1%的为溪畔银莲花和红花岩黄芪;回收率在1%～10%范围内的为垂穗披碱草、铁棒槌、迷果芹、高山韭、糙毛鹅冠草、线叶嵩草、窄果苔草、无芒雀麦、紫羊茅和赖草;回收率在10%～20%的为青藏苔草和砂生槐。
经过绵羊消化道后种子回收率大于20%的为黄花棘豆、披针叶黄华和镰形棘豆;回收率小于1%的为垂穗披碱草、铁棒槌、迷果芹、糙毛鹅冠草、红花岩黄芪、溪畔银莲花、无芒雀麦和紫羊茅;回收率在1%～10%范围内的为青藏苔草、马蔺、珠芽蓼、珠芽、皱叶酸模、狼毒、高山韭、线叶嵩草、醉马草和砂生槐;回收率在10%～20%的为无脉苔草、扁蓿豆、轮叶马先蒿、双柱头藨草、密花香薷、灰绿藜、华扁穗草、水葱、红棕苔草和车前。
种子经过牦牛和绵羊消化道后,发芽率升高的有无脉苔草、红棕苔草、镰形棘豆和灰绿藜和双柱头藨草;经过牦牛消化道后种子发芽率提高而经绵羊消化道未提高的有珠芽蓼、线叶嵩草和华扁穗草;发芽率明显降低的有禾草、黄花棘豆、皱叶酸模、铁棒槌、迷果芹、高山韭、轮叶马先蒿、披针叶黄华、密花香薷和车前,保持不变的有青藏苔草、马蔺、珠芽、狼毒、砂生槐、阴山扁蓿豆和水葱。
在天祝高寒草地11～4月份的牦牛粪中,共鉴定出43种植物,平均每块牦牛粪中的种子数为45粒。
通过2008年和2009年连续两年的研究,在中度放牧牦牛、中度放牧绵羊、中度牦牛绵羊混合放牧的3块放牧强度相近的样地中,单纯放牧绵羊草地的产草量明显高于牛羊混合放牧和单纯放牧牦牛的草地,而牛羊混合放牧草地的产草量也明显高于单纯放牧牦牛的草地。相似的结果还表现在植物高度、枝条总密度上。中度放牧绵羊、中度牦牛绵羊混合放牧、中度放牧牦牛的3样地产草量分别为581 g/m2、476 g/m2、411g/m2。
中度放牧绵羊的草地植被群落的Shanno-Wiener多样性指数为4.5825,明显低于中度放牧牛羊和中度放牧牦牛的草地;牛羊混合放牧草地,在中度放牧下植被群落的Shanno-Wiener多样性指数最大,重度放牧下最小。中度放牧牦牛草地上植物种数多于中度放牧牛羊和中度放牧绵羊草地。混合放牧牛羊草地,中度放牧条件下物种数最大,重度放牧条件下最小。中度放牧牦牛草地Pielou均匀性指数最高,其次为中度放牧牛羊、中度放牧绵羊。
中度放牧绵羊草地土壤较为松软,中度放牧牦牛草地土壤紧实度较高,中度放牧牛羊草地居于二者之间。土壤速效钾、速效氮、速效磷、全氮、全磷含量最高为中度放牧绵羊草地,其次为中度放牧牛羊草地,最低为中度放牧牦牛草地。土壤有机质含量为中度放牧羊草地显著高于中度放牧牛羊和中度放牧牦牛草地,而中度放牧牛羊草地低于中度放牧牦牛草地,但差异不显著。中度放牧绵羊草地土壤中性磷酸酶、过氧化氢酶和土壤尿酶活性均高于中度放牧牛羊、中度放牧牦牛草地。除0～10cm土壤尿酶活性外,中度放牧牛羊草地土壤中性磷酸酶、过氧化氢酶和土壤尿酶活性均高于中度放牧牦牛草地。
综上所述,在青藏高原高寒草地上,燃烧牦牛粪使灌丛草地免于砍伐,间接地保护了灌丛草地。冷季牦牛粪的堆积造成至少2年产草量的降低,而牦牛粪的捡走减轻了牛粪堆积对草地的危害。由于牦牛粪中含有较多的N、P、K等养分和可萌发的种子,因此捡走牦牛粪引起草地生态系统中养分和种子的流失,且这种流失作用随着放牧强度的增大呈增加趋势,这使牦牛粪对青藏高原高寒草地健康的维系作用弱化。在草地上将牦牛粪进行破碎化处理,或进行堆肥后归还草地,方可解决牛粪堆积与捡走牛粪的矛盾,使牦牛粪对青藏高原高寒草地健康的维系作用得以保持。由于牦牛粪绝大多数被捡走,而绵羊粪绝大多数留在草地上,这是导致放牧绵羊更有益于青藏高原高寒草地健康的部分原因。基于上述研究,本文提出了“多绵羊少牦牛”高寒草地放牧畜牧业经营管理模式。
Alpine grassland on Tibetan plateau is one of important pastoral areas in China and is the general basis for the survival of Tibetan people. The stability of alpine grassland ecosystem has enormous impact on the climate of Eastern and Southwestern China, but also has a significant impact on the climate of northern hemisphere, even the world's climate. However, the increasingly serious problem of grassland degradation has posed a serious threat on the Tibetan Plateau even surrounding area’s ecological environment and socio-economic sustainable development.
On Tibet Plateau, yak dung was collected from the alpine grassland to fuel and was herders’reliable fuel fueled for cooking, making tea and warming. Collecting dung lead to nutrients and seeds decrease in alpine grassland, but burning yak dung reduced bush logging in the shrub grassland. In fact, it has protected the shrub grassland by fueling the yak dung. The yak dung has the role of maintenance for Qinghai-Tibet Plateau alpine grassland health, which has not been reported in literature. So a series experimental tests were studied systematically which included: 1) investigating the total volume of cow dung systematically fueled by herders in Tibetan plateau pasturing area, study how much areas shrub grassland is protected from damage and destruction with fueling yak dung by investigating yak dung amount fueled and testing calorific value of yank dung and shrubs, quantizing how much grassland ecosystem nutrients were lost by collecting yak dung; 2) the influence of yak dung accumulation on alpine grassland ecosystem by artificial accumulated yak dung on alpine grassland; 3) observing the defecation characteristics of yak, studying the digestibility characteristics of yak and sheep, quantizing how much cow dung needed one person per year as fuel; 4) the mechanism and process of endozoochorous seed dispersal by yak and sheep in Tianzhu alpine grassland on alpine grassland seeds, and whether the seeds defecated by yak and sheep are easily germinating; 5) the influence of grazing system which grazing yaks and sheep only and mixed on grassland soil, species biodiversity and forage product. The main results obtained are as followed.
Moisture content of the yak dung applied for accumulation experiment was 75%. Total N, P and K was 1.33%, 0.159% and 0.626%, total organic matter was 51.87%, pH was 6.84. Dung was still present in the field after one year’accumulation. Yak dung (treatment) decreased soil pH, increased soil EC, improved soil physical properties of alpine meadow, reduced soil bulk density and increased soil moisture significantly. The accumulation of the yak dung increased the available N, total N, available P, total P, available K and organic matter content of soil under yak dung and around dung 10 cm.
Yak dung accumulation caused above-ground plants death under dung for poor oxygen content and less light in the first year. After yak dung accumulating one year and five months, total forage product around dung 10 cm was significantly higher than the control. For yak dung patch overlapped plants and caused the death of forage, its accumulation caused forage product decline. It is a dilemma that moving down yak dung from alpine grassland made soil nutrient and soil seed losses while accumulation made forage production decreased.
The calorific value of yak dung ranged from 15.38 to 17.89 KJ / g, and the average is 16.47 KJ / g. Among 21 species shrubs tested, the calorific value ranged from 17.80 to 24.26 KJ / g, and the average is 21.22 KJ / g. The average volume of yak dung fueled annual each herdsman in Zhuaxixiulong Township of Tianzhu County in Gansu Province, Huangcheng Township of Sunan County in Gansu Province, Dawu Township of Maqin County in Qinghai Province and Gulu
Township of Naqu County in Tibet was 2182 kg, 590 kg, 9233 kg and 3595 kg, respectively. The average volume of shrub yields which are reduced by fueling yak dung in the four places were 1702, 460, 7202 and 2804 kg or area equivalent 1229, 332, 5200 and 2025 m2.
The monthly average of total phosphorus, total nitrogen, total potassium and total organic carbon content in yak dung is 0.4974%, 2.031%, 0.665% and 39.41%, while which in sheep dung is 0.5026 %, 1.954 %, 0.707 % and 41.14 %, respectively. Approximately, 11, 3, 46 and 18 kg P, 44, 12, 188 and 73 kg N, 15, 4, 61 and 24 kg K was fueled each herdsman annually in four places mentioned frontly, respectively.
Integrating the defecation volume of whole year, the annual defecation amount of yak in cluster was 2.0 kg / d ? head. So, 5.2, 1.5, 12.7 and 5.0 yaks can meet herder's yak dung needs for four places mentioned frontly, respectively.
At the end of April, in Zhaxixiulong Township of Tianzhu County, grazing time on the grassland is 7 hours and 30 minutes. The proportion of dung weight defecated on the grassland was 35.65 percent. According to whole group of yaks defecation, total occupation area was per yak defecated was 0.194m2, and grassland area covered by each yak’s defecation per day was about 0.078 m2.
Yak apparent digestibility of mixed-grass in October and February was 63.22 % and 61.81%, of highland barley straw in January was 61.81%, and of oat hay in April was 59.42%. Sheep apparent digestibility of mixed grass in October and February was 53.68% and 57.64%, of oat hay in January and April were 57.25% and 55.18%.
Recoverage proportion of alpine grassland plant seeds defecated by yak and sheep was different by animal and species. Oxytropis ochrocephala, Iris lacteal, Polygonum viviparnm, Rumex crispus, Thermopsis lanceolata, Stellera chamaejasme, Pocockia ruthenia, Achnatherum inebrians, Scirpus distigmaticus, Elsholtzia densa, Chenopodium glaucum, O. falcate, Blysmus sinocompressus, Scirpus validus, Carex przewalski, C. enervis, Pedicularis verticillata, P. multicaulis, Plantago asiatica seeds and bulbil of P. viviparnm recoverage propoion fefacated by yak was greater than 20 percent; Anemone rivularis and Hedysarum multifugum seeds recoverage propoion was smaller than one percent; Elymus nutans, Aconitum szechenyianum, Sphallerocarpus gracilis, Allium sikkimense, Roegneria hirsute, Kobresia capillifolia, C. angustifructus, Bromus inermis, Festuca ruba and Leymus secalinum seeds recoverage propoion was range from 1 to 10 percent; and C. moorcroftii and Sophora moocroftiana seeds recoverage proportion was range from 10 to 20 percent.
O. ochrocephala, T. lanceolate and O. falcata seeds recoverage propoion fefacated by sheep was greater than 20 percent, E. nutans, A. szechenyianum, S. gracilis, R. hirsute, H. multifugum, A. rivularis, B. inermis and F. ruba seeds recoverage propoion was smaller than one percent, and C. moorcroftii, I. lacteal, R. crispus, S. chamaejasme, A. sikkimense, K. capillifolia, A. inebrians, S. moocroftiana and P. viviparnm seeds and Bulbil of P. viviparnm seeds recoverage propoion was range from 1 to 10 percent, C. enervis, P. ruthenia, P. verticillata, S. distigmaticus, E. densa, C. glaucum, B. sinocompressus, S. validus, C. przewalski and P. asiatica seeds recoverage proportion was range from 10 to 20 percent.
Seed of C. enervis, C. przewalski, O. falcate, C. glaucum and S. distigmaticus defecated by yak and sheep germination was promoted. P. viviparnm, K. capillifolia and B. sinocompressus seeds germination was promoted passed yak’s digestive tract but that was not passed sheep’s’. Grasses, O. ochrocephala, R. crispus, A. szechenyianum, A. sikkimense, P. verticillata, T. lanceolata, E. densa and P. asiatica seeds germination was reduced, and seeds of C. moorcroftii, I. lacteal, S. chamaejasme, S. moocroftiana, P. ruthenia and S. Validus seeds, and P. viviparnm bulbil germination was unchanged.
There are 43 species identified in yak dung from Nov. to April, and there are 45 grain seeds per piece of yak dung.
In three grassland plots grazed with similar intensity including grazing yak moderately, and grazing sheep moderately, whether in 2008 or 2009, the forage yield of plot only grazing sheep was higher than the remaining two, and which of grazing yak and sheep was higher than the plot grazing yak he yak The average forage yield of 2008 and 2009 on grazing sheep only, yak and sheep, and only yak is 581, 476 and 411 g/m2, respectively. Similar results were appeared in plant height and total shoot density.
The Shannon-Wiener diversity index of the grassland grazing sheep moderately is 4.5825, lower than that of grazing yak and sheep moderately and that of grazing yak moderately, of grazing yak. Similar result appeared in Pielou evenness index .The biggest Shannon-Wiener diversity index appeared on moderate grazing plot and smallest appeared on heavy grazing plot in mixed grazing with yak and sheep plots. Species numbers of the grassland grazing yak moderately is more than mixed grazing moderately plot with yak and sheep and grazing sheep moderately. Yak and sheep mixed rangeland, the species number increased firstly, and then decreased as grazing intensity increasing, that is, under moderate grazing the species number was highest.
Soil bulk density in plot with grazing sheep moderately was smaller than grazing mixed with yak and sheep, the biggest was the grassland grazing yak moderately. Opposite result appeared in soil available potassium, available nitrogen, available phosphorus, total nitrogen and total phosphorus content. Soil organic matter content in grazing sheep moderately is significantly higher than that of grazing mixed with yak and sheep and grazing yak moderately, while which of grazing yak moderately is higher than that grazing mixed with yak and sheep.
Soil neutral phosphatase, catalase and urease enzyme activity in plot with grazing sheep moderately was higher than grazing mixed with yak and sheep, the smallest was the grassland grazing yak moderately except soil urease enzyme activity form 0 to 10 cm.
On Tibet Plateau alpine grassland, burning yak dung reduced bush logging, so it has protected the shrub grassland by fueling the yak dung. For accumulation of yak dung defecated in cold season on alpine grassland led to forage product decline at least two years while removed yak dung from alpine grassland made the harm caused by yak dung accumulation eliminated. As there are lots of N, P, K and other components and some germinable seeds in yak dung defecated in cold season, so collecting dung lead to nutrients and seeds losses in alpine grassland, and the losses increased with the growing grazing intensity. Which weakened the maintenance of yak dung for Qinghai-Tibet Plateau alpine grassland health. Break down yak dung on alpine grassland or return to grassland after composting, which can resolve the dilemma that dung accumulation and removing, and maintenance of yak dung on the alpine grassland health is maintained. Most of yak dung was removed from grassland while sheep dung was keeping, which was one of reasons made grazing sheep was more benefit alpine grassland than grazing yak on Tibet Plateau. So, for above reason,“more sheep and fewer yaks”grazing livestock management mode on alpine grassland was proposed in this paper.
引文
[1]孙飞达.高原鼠兔洞穴密度对高寒草甸初级生产力及土壤特性的影响[D].甘肃农业大学博士学位论文,2008.
[2]龙瑞军.青藏高原草地生态系统之服务功能[J].科技导报,2007,25(9):26-28.
[3]崔庆虎,蒋志刚,刘季科,等.青藏高原草地退化原因述评[J].草业科学,2007,24(5):20-26.
[4]周华坤,赵新全,周立,等.青藏高原高寒草甸的植被退化与土壤退化特征研究[J].草业学报,2005,14(3):31-40.
[5]王辉,任继周,袁宏波.黄河源区高寒草地沙化进程中土壤物理性质的变化[J].草业学报,2007,16(1):30-33.
[6]王一博,王根绪,张春敏,等.高寒植被生态系统变化对土壤物理化学性状的影响[J].冰川冻土,2007,29(6):921-927.
[7]王根绪,胡宏昌,王一博,等.青藏高原多年冻土区典型高寒草地生物量对气候变化的响应[J].冰川冻土,2007,29(5):671-679.
[8]王根绪,李元首,吴青柏,等.青藏高原冻土区冻土与植被的关系及其对高寒生态系统的影响[J].中国科学(D辑:地球科学),2006,36(8):743-754.
[9]杨元合,朴世龙.青藏高原草地植被覆盖变化及其与气候因子的关系[J].植物生态学报,2006,30(1):1-8.
[10]曹广民,吴琴.土壤-牧草氮素供需状况变化对高寒草甸植被演替与草地退化的影响[J].生态学杂志,2004,23(6):25-28.
[11]赵亮,古松,徐世晓,等.青藏高原高寒草甸生态系统碳通量特征及其控制因子[J].西北植物学报,2007,27(5):859-863.
[12]王俊峰,王根绪,王一博.青藏高原沼泽与高寒草甸草地退化对生长期CO2排放的影响[J].科学通报,2007, 52(3):1154-1160.
[13]侯扶江,杨中艺.放牧对草地的作用[J].生态学报,2006,26(1):244-264.
[14]汪诗平.草原植物的放牧抗性[J].应用生态学报,2004,15(3):517-522.
[15]高英志,韩兴国,汪诗平.放牧对草原土壤的影响[J].生态学报,2004,24(4):790-797.
[16]李文龙,张彦宇,李自珍,等.高寒草地植物生态位适宜度与生产力和多样性的关系及其对放牧的响应[J].兰州大学学报(自然科学版),2007,43(2):53-57.
[17]李向林.植物对食草动物采食的超补偿反应[J].草原与草坪,1997,(3):9-13.
[18]王长庭,王启基,龙瑞军,等.高寒草甸群落植物多样性和初级生产力沿海拔梯度变化的研究[J].植物生态学报,2004,28(2):240-245.
[19]王长庭,龙瑞军,曹广民,等.三江源地区主要草地类型土壤碳氮沿海拔变化特征及其影响因素[J].植物生态学报,2006,30(3):441-449.
[20]曹广民,龙瑞军.三江源区“黑土滩”型退化草地自然恢复的瓶颈与解决途径[J].草地学报,2009,17(1):4-9.
[21]王启兰,姜文波.青藏高原金露梅灌丛与矮嵩草草甸枯枝落叶的分解作用[J].草地学报,2001,9(2):128-132.
[22]王启兰,曹广民,姜文波,等.高寒湿地植物残体降解的动态分析[J].草业学报,2004,13(4):39-44.
[23]高永恒,陈槐,罗鹏,等.放牧强度对川西北高山草甸两个优势物种凋落物分解的影响[J].生态科学,2007,26(3):193-198.
[24]王湘国.黄河源区草地鼠虫害的现状及防治对策[J].青海草业,2000,9(2):19-20,18.
[25]吴宁,罗鹏.长江上游高寒草地生态建设和管理中生态理论的若干质疑[J].应用与环境生物学报,2004,10(4):537-542.
[26]拉毛,侯秀敏.论青海省草地鼠虫害治理的思路与对策[J].草业与畜牧,2007,(5):42-43,62.
[27]丁路明,龙瑞军,杨予海,等.牦牛夏秋季和冬季各草场牧食行为的研究[J].中国畜牧杂志,2007,43(5):52-54.
[28]董全民,赵新全,李青云,等.牦牛放牧强度对小嵩草高寒草甸草场生产力的影响研究[J].家畜生态学报,2006,27(4): 73-77.
[29]董全民,赵新全,马玉寿.放牧强度对高寒人工草地土壤有机质和有机碳的影响[J].青海畜牧兽医杂志,2007,37(1):6-8.
[30]李希来,黄葆宁.青海“黑土滩”草地成因及治理途径[J].中国草地,1995,(4):64-67.
[31]马玉寿.三江源区“黑土型”退化草地形成机理与恢复模式研究[D].甘肃农业大学博士学位论文,2006.
[32]马玉寿,张自和,董全民,等.恢复生态学在“黑土型”退化草地植被改建中的应用[J].甘肃农业大学学报,2007,42(2):91-97.
[33]王启基,来德珍,景增春,等.三江源区资源与生态环境现状及可持续发展[J].兰州大学学报,2005,41(4):50-55.
[34]周显辉.青藏高原高寒草甸土壤种子库研究[D].兰州大学硕士学位论文,2006.
[35]尚占环,丁玲玲,龙瑞军,等.江河源区高寒草地土壤微生物数量特征[J].草原与草坪,2006,(5):3-7.
[36]尚占环,龙瑞军,马玉寿.青藏高原江河源区生态环境安全问题分析与探讨[J].草业科学,2007,24(3):1-7.
[37]彭岳林,蔡晓布,薛会英.退化高寒草原土壤微生物变化特性研究[J].西北农业学报,2007,16(4):112-115.
[38] Betteridge K, Andrewes WG K, Sedcole J R. Intake and excretion of nitrogen, potassium and phosphorus by grazing steers [J]. Journal of Agricultural Science, 1986, 106: 393-404.
[39] Williams BL, Shand CA, Sellers S, et al. Impact of synthetic sheep urine on N and P in two pastures in the Scottish uplands [J]. Plant and Soil, 1999, 214: 93-103.
[40] Allen A G, Jarvis S C, Headon D M. Nitrous oxide emissions from soils due to inputs of nitrogen from excreta return by livestock on grazed grassland in the U.K [J]. Soil Biology and Biochemistry, 1996, 28: 597-607.
[41] Semmatrin M, Oesterheld M. Effects of grazing pattern and nitrogen availability on primary productivity [J]. Oecologia, 2001, 126: 225-230.
[42] Kebreab E, France J, Beerer DE, et al. Nitrogen pollution by dairy cows and its mitigation by dietary manipulation [J]. Nutrient Cycling in Agroecosystems, 2001, 60: 275-285.
[43] Sharon R A, Catherine R O’C, Hossein M H, et al. Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems[J]. Nutr Cycl Agroecosyst, 2008, DOI 10. 1007/s 10705-008-9228-5.
[44]李辉霞,王青,陈国阶.高原牛粪:理想与生存的实证[J].生态经济,2003,8:29-31.
[45]张建国,刘淑珍,李辉霞,等.西藏那曲地区草地退化驱动力分析[J].资源调查与环境,2004,25(2):98-100.
[46] Williams P H, Haynes R J. Effects of sheep, deer and cattle dung on herbage production and soil nutrient content[J]. Grass & Forage Science, 1995, 50: 263-271.
[47]姜世成,周道玮.牛粪堆积对草地影响的研究[J].草业学报,2006,15(4):30-35.
[48]何奕忻,孙庚,罗鹏,等.牲畜粪便对草地生态系统影响的研究进展[J].生态学杂志,2009, 28(2):322-328.
[49]马玉寿,郎百宁,王启基.“黑土型”退化草地研究工作的回顾与展望[J].草业科学,1999,16(2): 5-9.
[50]李志昆.青海省高原草地生态系统退化的成因分析[J].养殖与饲料,2008,(5):68-71.
[51]王宝山,尕玛加,张玉.青藏高原“黑土滩”退化高寒草甸草原的形成机制和治理方法的研究进展[J].草原与草坪,2007,(2):72-77.
[52]周兴民.中国嵩草草甸[M].北京:科学出版社,2001.
[53]武高林,杜国祯.青藏高原退化高寒草地生态系统恢复和可持续发展探讨[J].自然杂志,2007,29(3):159-164.
[54] Liu X, Chen B. Climatic warming in the Tibetan Plateau during recent decades [J]. Int. J. Climatol., 2000, 20(14): 1729-1742.
[55] Klein J A, Harte J, Zhao X Q. Experimental warming causes large and rapid species loss, dampened by simulated grazing, on the Tibetan Plateau [J]. Ecology Letters, 2004, 7: 1170-1179.
[56]王根绪,李玉其,程国栋. 40年来江河源区气候变化特征及其生态环境效应[J].冰川冻土,2001,23(4):346-352.
[57] Du M, Shigeto K, Seiichiro Y, et al. Mutual influence between human activities and climate change in the Tibetan Plateau during recent years [J]. Global and Planetary Change, 2004,41: 241-249.
[58]白小明,蒲小鹏.金强河地区高寒草地气候变化分析[J].草业科学,2003,20(7):51-53.
[59] You Q, Kang, S, Aguilar E, et al. Changes in daily climate extremes in the eastern and central Tibetan Plateau during 1961–2005 [J]. Journal of Geophysical Research, 2008, 113 (d7): D07101-1-D07101-17.
[60]龙瑞军,董世魁,胡自治.西部草地退化的原因分析与生态恢复措施探讨[J].草原与草坪,2005,(6):3-7.
[61]张耀生,赵新全,周兴民.青海省草地畜牧业可持续发展战略与对策[J].自然资源学报,2000,15(4):328-334.
[62]周立志,李迪强,王秀磊,等.三江源自然保护区鼠害类型、现状和防治策略[J].安徽大学学报(自然科学版),2002,26(2):87-96.
[63]何昌茂.面向新世纪,牧区畜牧业要大发展——关于加快发展我国草原畜牧业几个问题的探讨[J].四川草原,2000,(2):1-6.
[64]王录仓江河源区草场退化的生态环境后果及成因[J].草业科学,2004,21(1):17-19.
[65]兰玉蓉.青藏高原高寒草甸草地退化现状及治理对策[J].青海草业,2004,13(1):27-30.
[66]何孝德,王薇娟.青海省草原毛虫分布区域及为害等级划分初探[J].草业科学,2003,20(8):45-47.
[67] Shiponeni N N, Milton S J. Seed dispersal in the dung of large herbivores: implications forrestoration of Renosterveld shrub land old fields [J]. Biodiversity and Conservation, 2006, 15: 3161-3175.
[68] Janzen D H. Herbivores and the number of tree species in tropical forest [J]. The American naturist, 1970, 104: 501-528.
[69] Janzen D H. Seed predation by animals [J]. Annual review of ecology and systematics, 1971, 2: 465-492.
[70] Nathan R, Muller-Landau H C. Spatial patterns of seed dispersal, their determinants and consequences for recruitment[J]. Trends in Ecology & Evolution, 2000, 15: 278-285.
[71] Willson M, Traveset A. 2000. The ecology of seed dispersal. In: Seeds: The ecology of regeneration in plant communities. 2 nd. Edition[M]. M. Fenner (ed.). Wallingford: CAB International. pp. 85–110.
[72]解兴词.阔叶红松林主要组成树种的种子扩散格局[D].东北林业大学硕士论文,2007.
[73] Harper J L. Population Biology of Plants [M]. London: Academic Press, 1977.
[74] Willson M F. Dispersal mode, seed shadows, and colonization patterns[J]. Plant Ecology, 1993, 261-280.
[75] Clark J S, Silman M, Kern R, et al. Seed Dispersal near and far: patterns across temperate and tropical forests[J]. Ecology, 1999, 80: 1475-1494.
[76] Hoekstra N J, Bosker T, Lantinga E A. Effects of cattle dung from farms with different feeding strategies on germination and initial root growth of cress (Lepidium sativum L.) [J]. Agriculture, Ecosystems and Environment, 2002, 93: 189-196.
[77] Nishi H, Tsuyuzaki S. Seed dispersal and seedling establishment of Rhus trichocarpa promoted by a crow (Corvus macrorhynchos ) on a volcano in Japan[J]. Ecography, 2004, 27: 311-322.
[78] Herrera C M, Jordano P, López-Soria L, et al. Recruitment of a mast-fruiting, bird-dispersed tree: bridging frugivore activity and seedling establishment[J]. Ecological Monographs, 1994, 64: 315-344.
[79]鲁长虎.动物对松属植物种子的传播作用研究进展[J].生态学杂志,2006,25(5):557-562.
[80] Couvreur M, Cosyns E, Hermy M, et al. Complementarity of epi- and endozoochory of plant seeds by free ranging donkeys[J]. Ecography, 2005, 28: 37-48.
[81] Debussche M, Isenmann P. Fleshy fruit characteristics and the choices of bird and mammal seed dispersers in a Mediterranean region[J]. Oikos, 1989, 56: 327-338.
[82] Amico G, and Aize M A. Mistletoe seed dispersal by a marsupial[J]. Nature, 2000, 408: 929-930.
[83] Tabarelli M, Peres C A. Abiotic and vertebrate seed dispersal in the Brazilian Atlantic forest: implications for forest regeneration[J]. Biol. Conserv.,2003, 106: 162-176.
[84] Welch D. Studies in the grazing of heather moorland in north-east Scotland [J]. J. Appl. Ecol., 1985, 22: 461-472.
[85] Gardener C J, McIvor J G, Jansen A. Passage of legume and grass seeds through the digestive tract of cattle and their survival in faces [J]. J. Appl. Ecol., 1993, 30: 63-74.
[86] Malo J E, Sua′rez F. Establishment of pasture species on cattle dung: the role of endozoochorous seeds [J]. J. Veg. Sci., 1995, 6: 169-174.
[87] Pakeman R J, Digneffe G, Small J L. Ecological correlates of endozoochory by herbivores [J]. Functional Ecology, 2002, 16: 296-304.
[88] Cosyns E. Ungulate seed dispersal. Aspects of endozoochory in a semi-natural landscape [D]. Ph.D. thesis, Ghent, Ghent Univ, 2004.
[89] Traveset A. Effect of seed passage through vertebrate frugivores' guts on germination: a review[J]. Perspectives in Plant Ecology, Evolution and systematics, 1998, 1(2): 151-190.
[90] Mouissie A M, Van Der Veen C E J, Veen G F C, et al. Ecological correlates of seed survival after ingestion by Fallow Deer [J]. Functional Ecology, 2005, 19, 284-290.
[91] Vellend M, Myers J A, Gardescu S, et al. Dispersal of Trillium seeds by deer: implications for long-distance migration of forest herbs [J]. Ecology, 2003, 84(4): 1067-1072.
[92] G?kbulak F. Effect of American bison (Bison bison L.) on the recovery and germinability of seeds of range forage species [J]. Grass and Forage Science, 2002, 57, 395-400.
[93] Espinar J L, García L V, Figuerola J, et al. Effects of salinity and ingestion by ducks on germination patterns of Juncus subulatus seeds [J]. Journal of Arid Environments, 2006, 66: 376-383.
[94] Ramos M E, Robles A B, Castro J. Efficiency of endozoochorous seed dispersal in six dry-fruited species (Cistaceae): from seed ingestion to early seedling establishment [J]. Plant Ecology, 2006, 185: 97-106.
[95] Cosyns E, Delporte A, Lens L, et al..Germination success of temperate grassland species after passage through ungulate and rabbit guts[J]. Journal of Ecology, 2005, 93: 353-361.
[96] Otani T. Effects of macaque ingestion on seed destruction and germination of a fleshy-fruited tree, Eurya emarginata[J]. Ecological Research, 2004, 19: 495-501.
[97] Ghassali F, Osman A E, Cocks P S. Rehabilitation of degraded grasslands in north Syria: the use of Awassi sheep to disperse the seeds of annual pasture legumes [J]. Experimental Agriculture,1998, 34: 391-405.
[98] Traba J, Levassor C, Peco B. Restoration of Species Richness in Abandoned Mediterranean Grasslands: Seeds in Cattle Dung [J]. Restoration Ecology, 2003, 11(3): 378-384.
[99] Myers J A, Vellend M, Gardescu S, et al. Seed dispersal by white-tailed deer: implications for long-distance dispersal, invasion, and migration of plants in eastern North America [J]. Oecologia, 2004, 139: 35-44.
[100] Milton S J, Dean W R. Seeds dispersed in dung of insectivores and herbivores in semi-arid southern Africa [J]. Journal of Arid Environments, 2001, 47: 465-483.
[101] Yamashiro A. Seed Dispersal by Kerama Deer (Cervus nippon keramae) on Aka Island, the Ryukyu Archipelago, Japan [J]. Biotropica, 2006, 38(3): 405-413.
[102]张学勇,杨允菲,亓娜,等.草食动物对结缕草种子散布及发芽力的影响[J].生态学杂志,2007,26(9):1491-1494.
[103]曹林.都江堰亚热带森林动物对樱桃果实/种子的捕食和扩散[D].四川大学硕士学位论文,2006.
[104]马瑞君,鲁先文,孙坤,等.灰喜鹊摄食对中国沙棘种子萌发的影响[J].西北植物学报,2005,25(3):472-477.
[105]唐占辉,盛连喜,马逊风,等.两种果蝠对光叶桑(Morus macroura)果实的取食及种子传播[J].生态学报,2007,27(5):1895-1902.
[106]申仕康,胡晓立,王跃华.鸟类对猪血木种子的散布及在其保护中的意义[J].广西植物,2008,28(5):650 -654.
[107]鲁先文,孙坤,马瑞君,等.鸟类取食中国沙棘果实的方式及其对种子的传播作用[J].生态学杂志,2005,24(6):635-638.
[108]余冠军,尹华宝,王贵林,等.鼬獾对枳椇种子选择和消化时间的研究[J].生物学杂志,2008,25(3):51-53,77.
[109]范朋飞,黄蓓,蒋学龙.云南无量山黑长臂猿对植物种子的传播作用[J].兽类学报,2008,28(3):232-236.
[110]匡崇义,徐驰,薛世明,等.亚热带牧用草地中威提特东非狼尾草的种子繁殖研究[J].四川草原,2004,10:8-10.
[111]达来,凹特根,占布拉,等.绵羊粪中排出的牧草种子及其发芽率研究[J].中国草地,1994,5:23-27.
[112] Trlica M J, Rittenhouse L R. Grazing and plant performance [J]. Ecological Applications, 1993, 3(1): 21-23.
[113] Noy-Meir I. Compensating growth of grazed plant and its relevance on the use of rangelands [J]. Ecological Applications, 1993, 13(1): 32-34.
[114]赵钢.草地畜牧业可持续发展刍议[J].内蒙古草业,1999,(2):1- 6.
[115]沈景林,谭刚,乔海龙,等.草地改良对高寒退化草地植被影响的研究[J].中国草地,2000,(5):49-54.
[116]汪诗平,李永宏,王艳芬,等.不同放牧率对内蒙古冷蒿草原植物多样性的影响[J].植物学报,2001,43(1):89-96.
[117]刘发央,徐长林,龙瑞军.牦牛放牧强度对金露梅灌丛草地群落物种多样性的影响[J].草地学报,2008,16(6):613-618.
[118]王启基,周兴民,张堰青,等.放牧对金露梅生长发育和生物量的影响[A].高寒草甸生态系统[C].北京:科学出版社,1991.
[119]董全民,马玉寿,李青云,等.牦牛放牧率对高寒小嵩草草甸植物群落的影响[J].中国草地,2004,26(3):24-32.
[120]董全民,赵新全,李青云,等.牦牛放牧率对小嵩草高寒草甸暖季草场植物群落组成和植物多样性的影响[J].西北植物学报,2005,25(1):94-102.
[121]盛海彦,曹广民,李国荣,等.放牧干扰对祁连山高寒金露梅灌丛草甸群落的影响[J].生态环境学报,2009,18(1):235-241.
[122]王仁忠.羊草种群能量生殖分配的研究[J].应用生态学报,2000,11(4):591-594.
[123]白哈斯.不同放牧率对草甸植被特征的影响[J].干旱区资源与环境,2008,22(4):170-174.
[124]仁青吉,罗燕江,王海洋,等.青藏高原典型高寒草甸退化草地的恢复——施肥刈割对草地质量的影响[J].草业学报,2004,13(2):43-49.
[125]王长庭,龙瑞军,王启兰,等.放牧扰动下高寒草甸植物多样性、生产力对土壤养分条件变化的响应[J].生态学报,2008,28(9):4144-4152.
[126]沈广爽,张明海,夏茜,等.放牧鹿科动物对植物群落结构及物种多样性的影响[J].家畜生态学报,2009,30(3):88-90.
[127]于应文.滩羊尿对陇东黄土高原草地植物生长和群落结构的影响[D].兰州大学博士学位论文,2005.
[128]于应文,南志标.畜尿排泄特征及其对草地植被和家畜选择采食的作用[J].生态学报,2008,28(2):777-785.
[129]郑阳,徐柱,锡林图雅,等.放牧强度对土—草—畜系统的影响研究进展[J].草原与草坪,2009,(5):72-76.
[130]姚爱兴,李平,王培,等.不同放牧制度下奶牛对多年生黑麦草/白三叶草地土壤特性的影响[J].草地学报,1995,4(2):65-102.
[131]戎郁萍,韩建国,王培,等.放牧强度对草地土壤理化性质的影响[J].中国草地,2001,23(4):41-47.
[132]张蕴薇,韩建国,李志强.放牧强度对土壤物理性质的影响[J].草地学报,2002,10(1):74-78.
[133]王玉辉,何兴元,周广胜.放牧强度对羊草草原的影响[J].草地学报,2002,10(1):45-49.
[134]范春梅,廖超英,李培玉,等.放牧对黄土高原丘陵沟壑区林草地土壤理化性状的影响[J].西北林学院学报,2006,21(2):1-4.
[135] Greenwood K L, Macleod D A, Hutchinson K J. Long-term stocking rate effects soil physical properties[J]. Aus. J. Exp. Agric, 1997, 37: 413-419.
[136]董全民,赵新全,马玉寿,等.江河源区披碱草和星星草混播草地土壤物理形状对牦牛放牧强度的响应[J].草业科学,2005,22(6):65-70.
[137]周丽艳,王明玖,韩国栋.不同强度放牧对贝加尔针茅草原群落和土壤理化性质的影响[J].干旱区资源与环境,2005,19(7):182-186.
[138]贾树海,王春枝,孙振涛,等.放牧强度和放牧时期对内蒙古草原上土壤压实效应的研究[J].草地学报,1999,7(3):217-221.
[139]姚爱兴,王培.不同放牧强度下奶牛对多年生黑麦草/三叶草地土壤特性的影响[J].草地学报,1995,3(3):181-189.
[140]朱绍宏.牦牛放牧强度对高寒草原植被群落及土壤养分影响的研究[D].甘肃农业大学硕士学位论文,2006.
[141]付华,王彦荣,吴彩霞,等.放牧对阿拉善荒漠草地土壤形状的影响[J].中国沙漠,2002, 22(4):339-343.
[142]蒋文兰,张英俊,符义坤,等.绵羊啃食和践踏对植物与草地物理形状的影响[J].草业学报,1999,8(增刊):82-89.
[143]红梅,陈有君,李艳龙,等.不同放牧强度对土壤含水量及地上生物量的影响[J].内蒙古农业科技,2001,(3):25-26.
[144]郑云玲,李雪松,张瑞,等.放牧强度对草原土壤与植被的影响[J].内蒙古农业大学学报,2008,29(1):262-266.
[145]裴海昆.不同放牧强度对土壤养分及质地的影响[J].青海大学学报(自然科学板),2004,22(4):29-31.
[146]干友民,李志丹,王钦,等.川西北亚高山草甸放牧退化演替研究[J].草地学报,2005,13(S1):48-52.
[147]李香真,陈佐忠.不同放牧率对草原植物与土壤C, N,P含量的影响[J].草地学报,1998,6(2):90-98.
[148] Reeder J D, Schuman G E. Influence of livestock grazing on C sequestration in semi-arid mixed grass and short grass rangelands [J]. Environmental Pollution, 2002, 116(3): 457-463.
[149] Frank A B,Tanaka D L, Hofmann L. Soil carbon and nitrogen of Northern Great Plains grasslands as influenced by long-term grazing [J]. Journal of Range Management,1995, 48: 470-474.
[150]王艳芬,陈佐忠,Larry T.人类活动对锡林郭勒地区主要草原土壤有机碳分布的影响[J].植物生态学报,1998,22(6):545-551.
[151]王淑强,胡直友,李兆方.同放牧强度对红三叶、黑麦草草地植被和土壤养分的影响[J].自然资源学报,1996,11(3):280-287.
[152]白可喻,王培,韩建国,等.放牧强度对新麦草人工草地氮素在牧草与土壤中的分配和动态的影响[J].草地学报,1999,7(1):46-53.
[153] Abbasi M K, Adams W A. Estimation of simultaneous nitrification and denitrification in grassland soil associated with urea-N using15Nand nitrification inhibitor [J]. Biol Fertil Soils, 2000, 31: 38-44.
[154] Milchunas D G, Laurenroth W K. Quantitative effects of grazing on vegetation and soil over a global range of environments [J]. Ecological Monographs, 1993, 63(4): 327-366.
[155] Valentina Z, Michael B, Meinhard A, et al. Impact of land-use change on nitrogen mineralization in subline grasslands in the Southern Alps [J]. Biol Fertil Soi1s, 2000, 31: 441-448.
[156]杨智明,王宁,张志强.放牧对草原生态系统的影响.Ⅰ放牧对草原土壤的影响[J].宁夏农学院学报,2004,25(1):70-72,95.
[157]王华静,徐留兴,葛成冉,等.放牧强度对草地土壤性状影响的研究进展[J].安徽农业科学,2008,36(34):15074-15075.
[158]格尔丹.西藏的牛粪文化[J].西藏民俗,2003,(1):44-47.
[159]张宗显.西藏的牛粪火俗[J].中国西藏(中文版),2004,(2):63-65.
[160] Rhode D, Madsen D B, Brantingham P J, et al. Yaks, yak Dung, and prehistoric human habitation of the Tibetan Plateau[J]. Developments in Quaternary Sciences, 2007, (9): 205-225.
[161]贾宽河.雪域牛粪[J].西藏民俗,2000,(1):46-47.
[162]罗红英,刘钟泽.西藏薪柴能源替代战略与总体规划的探讨[J].能源工程,2009,(3):14-18.
[163]鱼小军,蒲小鹏,黄世杰,等.蚂蚁对东祁连山高寒草地生态系统的影响[J].草业学报,2010,19(2):140-145.
[164]秦泗国.近50年气候变化对那曲地区环境承载力的影响[D].西藏大学硕士学位论文,2009.
[165]柳小妮.甘肃省草地蝗虫预测预报专家系统的研究与开发[D].甘肃农业大学博士学位论文,2003.
[166]张贵谦,保国俊,李文辉,等.甘肃高山细毛羊的适应性调查研究报告[J].中国养羊,1996,(1):4-5.
[167]鲍士旦.土壤农化分析(第三版)[M].北京:中国农业出版社,2000.
[168]陈锋,汪有奎,杨正国,等.祁连山森林草原可燃物种类数量及特征初步分析[J]. 2008,24(14):171-174.
[169]张德罡.东祁连山杜鹃灌丛生态系统研究[M].甘肃教育出版社,2003.
[170]尚斌.畜禽粪便热解特性试验研究[D].中国农业科学院硕士学位论文,2007.
[171]龙瑞军,徐长林,胡自治,等.天祝高山草原15种饲用灌木的热值及季节动态[J].生态学杂志,1993,12(5):l3-l6.
[172]于应文,胡自治,张德罡,等.天祝金强河高寒地区金露梅的热值及其季节动态[J].草业科学,2000,17(2):1-4.
[173]官丽莉,周小勇,罗艳.我国植物热值研究综述[J].生态学杂志,2005,24(4):452-457.
[174]许鹏.草地资源调查规划学[M].中国农业出版社,2000.
[175] Hakamata T, Hirashima T, Okumura J. Management of pasture in the cold region II: transfer of the nitrogen, phosphate, and potassium in dung to soil and forage[C]. Bull Hokkaido Report of Hokkaido Prefectural Agricultural Experiment Station, 1971, 24: 82-92
[176] Aarons S R, O’Connor C R, Gourley C J P. Dung decomposition in temperate dairypastures I. Changes in soil chemical properties[J]. Australian Journal of Soil Research, 2004, 42:107–114. doi: 10.1071/SR03008.
[177]李德志,高桥繁男,祝廷成.粪斑对结缕草放牧草地根系层土壤氮素的影响[J].应用与环境生物学报,2005,11(3):312-314.
[178]严学兵,汪玺,张德罡.放牧牦牛瘤胃生理指标的测定[J].黄牛杂志,2003,29(3):14-17.
[179] Aarons S R, O’Connor C R, Hosseini H M, et al. Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems [J]. Nutrient Cycling in Agroecosystems, 2008, DOI 10. 1007/s10705-008- 9228-5.
[180] Weeda W C. The effect of cattle dung patches on pasture growth, botanical composition, and pasture utilization [J]. New Zealand Journal of Agricultural Research, 1967, 10: 150-159.
[181] Haynes R J, Williams P H . Nutrient cycling and soil fertility in the grazed pasture ecosystem[J]. Advances in Agronomy, 1993, 49: 119-199.doi: 10. 1016 /S0065-2113 (08)60794-4.
[182]姜世成,周道玮.草原牛粪对牲畜取食影响的研究[J].中国草地,2002,24(1):41-46.
[183] Holter P . Effect of dung beetles and earthworms on the disappearance of cattle dung [J]. Oikos, 1979, 32, 393-402.
[184] Yokoyama K, Kai H, Koga T, et al. N mineralization and microbial populations in cow dung, dung balls and underlying soil affected by paracoprid dung beetles [J]. Soil Biology & Biochemistry, 1991,23: 649-953.
[185] Kaneda S, Yamashita N, Uchida T, et al. Effects of ivermectin in dung pats on earthworm (Megascolecidae) populations and pat degradation in Japanese grassland. [J] Applied Soil Ecology, 2006, 31: 280-285.
[186] Lovell RD, Jarvis SC. Effect of cattle dung on soil microbial biomass C and N in a permanent pasture soil[J]. Soil Biology & Biochemistry, 1996, 28(3): 291-299.
[187] Vona L C, Jung G A, Reid R L, et al. Nutritive value of worm-season grass hays for beef cattle and sheep: Digetbility, intake and mineral utilization[J]. Journal of animal science, 1984, 59: 1582-1593.
[188]陈友慷,袁有清,茂林,等.成年母牦牛冷季采食量和消化率测定[J].中国牦牛,1 994,(2):29-32,68.
[189]龙瑞军,董世魁,胡自治.同一日粮下泌乳牦牛与干奶牦牛消化代谢能力的比较研究[J].草业学报,1998,7(3):51-55.
[190]严学兵,汪玺,郭玉霞.放牧牦牛采食量和几种消化生理指标的测定[J].中国草食动物,2003,23(5):5-7.
[191]朱兴运.绵羊采食量和消化率测定方法简况(综述)[J].四川草原,1983,(1):93-97.
[192] Manzano P, Malo J E, Peco B. Sheep gut passage and survival of Mediterranean shrub seeds.[J] Seed Science Research, 2005, 15:21–28.
[193]周礼恺.土壤酶学[M].北京:科学出版社,1987.
[194]马克平,刘玉明.生物群落多样性的测度方法Ⅰa多样性的测度方法(上)[J].生物多样性,1994,2(3):162-168.
[195]马克平,刘玉明.生物群落多样性的测度方法Ⅱa多样性的测度方法(下) [J].生物多样性,1994,2(4):231-239.
[2]龙瑞军.青藏高原草地生态系统之服务功能[J].科技导报,2007,25(9):26-28.
[3]崔庆虎,蒋志刚,刘季科,等.青藏高原草地退化原因述评[J].草业科学,2007,24(5):20-26.
[4]周华坤,赵新全,周立,等.青藏高原高寒草甸的植被退化与土壤退化特征研究[J].草业学报,2005,14(3):31-40.
[5]王辉,任继周,袁宏波.黄河源区高寒草地沙化进程中土壤物理性质的变化[J].草业学报,2007,16(1):30-33.
[6]王一博,王根绪,张春敏,等.高寒植被生态系统变化对土壤物理化学性状的影响[J].冰川冻土,2007,29(6):921-927.
[7]王根绪,胡宏昌,王一博,等.青藏高原多年冻土区典型高寒草地生物量对气候变化的响应[J].冰川冻土,2007,29(5):671-679.
[8]王根绪,李元首,吴青柏,等.青藏高原冻土区冻土与植被的关系及其对高寒生态系统的影响[J].中国科学(D辑:地球科学),2006,36(8):743-754.
[9]杨元合,朴世龙.青藏高原草地植被覆盖变化及其与气候因子的关系[J].植物生态学报,2006,30(1):1-8.
[10]曹广民,吴琴.土壤-牧草氮素供需状况变化对高寒草甸植被演替与草地退化的影响[J].生态学杂志,2004,23(6):25-28.
[11]赵亮,古松,徐世晓,等.青藏高原高寒草甸生态系统碳通量特征及其控制因子[J].西北植物学报,2007,27(5):859-863.
[12]王俊峰,王根绪,王一博.青藏高原沼泽与高寒草甸草地退化对生长期CO2排放的影响[J].科学通报,2007, 52(3):1154-1160.
[13]侯扶江,杨中艺.放牧对草地的作用[J].生态学报,2006,26(1):244-264.
[14]汪诗平.草原植物的放牧抗性[J].应用生态学报,2004,15(3):517-522.
[15]高英志,韩兴国,汪诗平.放牧对草原土壤的影响[J].生态学报,2004,24(4):790-797.
[16]李文龙,张彦宇,李自珍,等.高寒草地植物生态位适宜度与生产力和多样性的关系及其对放牧的响应[J].兰州大学学报(自然科学版),2007,43(2):53-57.
[17]李向林.植物对食草动物采食的超补偿反应[J].草原与草坪,1997,(3):9-13.
[18]王长庭,王启基,龙瑞军,等.高寒草甸群落植物多样性和初级生产力沿海拔梯度变化的研究[J].植物生态学报,2004,28(2):240-245.
[19]王长庭,龙瑞军,曹广民,等.三江源地区主要草地类型土壤碳氮沿海拔变化特征及其影响因素[J].植物生态学报,2006,30(3):441-449.
[20]曹广民,龙瑞军.三江源区“黑土滩”型退化草地自然恢复的瓶颈与解决途径[J].草地学报,2009,17(1):4-9.
[21]王启兰,姜文波.青藏高原金露梅灌丛与矮嵩草草甸枯枝落叶的分解作用[J].草地学报,2001,9(2):128-132.
[22]王启兰,曹广民,姜文波,等.高寒湿地植物残体降解的动态分析[J].草业学报,2004,13(4):39-44.
[23]高永恒,陈槐,罗鹏,等.放牧强度对川西北高山草甸两个优势物种凋落物分解的影响[J].生态科学,2007,26(3):193-198.
[24]王湘国.黄河源区草地鼠虫害的现状及防治对策[J].青海草业,2000,9(2):19-20,18.
[25]吴宁,罗鹏.长江上游高寒草地生态建设和管理中生态理论的若干质疑[J].应用与环境生物学报,2004,10(4):537-542.
[26]拉毛,侯秀敏.论青海省草地鼠虫害治理的思路与对策[J].草业与畜牧,2007,(5):42-43,62.
[27]丁路明,龙瑞军,杨予海,等.牦牛夏秋季和冬季各草场牧食行为的研究[J].中国畜牧杂志,2007,43(5):52-54.
[28]董全民,赵新全,李青云,等.牦牛放牧强度对小嵩草高寒草甸草场生产力的影响研究[J].家畜生态学报,2006,27(4): 73-77.
[29]董全民,赵新全,马玉寿.放牧强度对高寒人工草地土壤有机质和有机碳的影响[J].青海畜牧兽医杂志,2007,37(1):6-8.
[30]李希来,黄葆宁.青海“黑土滩”草地成因及治理途径[J].中国草地,1995,(4):64-67.
[31]马玉寿.三江源区“黑土型”退化草地形成机理与恢复模式研究[D].甘肃农业大学博士学位论文,2006.
[32]马玉寿,张自和,董全民,等.恢复生态学在“黑土型”退化草地植被改建中的应用[J].甘肃农业大学学报,2007,42(2):91-97.
[33]王启基,来德珍,景增春,等.三江源区资源与生态环境现状及可持续发展[J].兰州大学学报,2005,41(4):50-55.
[34]周显辉.青藏高原高寒草甸土壤种子库研究[D].兰州大学硕士学位论文,2006.
[35]尚占环,丁玲玲,龙瑞军,等.江河源区高寒草地土壤微生物数量特征[J].草原与草坪,2006,(5):3-7.
[36]尚占环,龙瑞军,马玉寿.青藏高原江河源区生态环境安全问题分析与探讨[J].草业科学,2007,24(3):1-7.
[37]彭岳林,蔡晓布,薛会英.退化高寒草原土壤微生物变化特性研究[J].西北农业学报,2007,16(4):112-115.
[38] Betteridge K, Andrewes WG K, Sedcole J R. Intake and excretion of nitrogen, potassium and phosphorus by grazing steers [J]. Journal of Agricultural Science, 1986, 106: 393-404.
[39] Williams BL, Shand CA, Sellers S, et al. Impact of synthetic sheep urine on N and P in two pastures in the Scottish uplands [J]. Plant and Soil, 1999, 214: 93-103.
[40] Allen A G, Jarvis S C, Headon D M. Nitrous oxide emissions from soils due to inputs of nitrogen from excreta return by livestock on grazed grassland in the U.K [J]. Soil Biology and Biochemistry, 1996, 28: 597-607.
[41] Semmatrin M, Oesterheld M. Effects of grazing pattern and nitrogen availability on primary productivity [J]. Oecologia, 2001, 126: 225-230.
[42] Kebreab E, France J, Beerer DE, et al. Nitrogen pollution by dairy cows and its mitigation by dietary manipulation [J]. Nutrient Cycling in Agroecosystems, 2001, 60: 275-285.
[43] Sharon R A, Catherine R O’C, Hossein M H, et al. Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems[J]. Nutr Cycl Agroecosyst, 2008, DOI 10. 1007/s 10705-008-9228-5.
[44]李辉霞,王青,陈国阶.高原牛粪:理想与生存的实证[J].生态经济,2003,8:29-31.
[45]张建国,刘淑珍,李辉霞,等.西藏那曲地区草地退化驱动力分析[J].资源调查与环境,2004,25(2):98-100.
[46] Williams P H, Haynes R J. Effects of sheep, deer and cattle dung on herbage production and soil nutrient content[J]. Grass & Forage Science, 1995, 50: 263-271.
[47]姜世成,周道玮.牛粪堆积对草地影响的研究[J].草业学报,2006,15(4):30-35.
[48]何奕忻,孙庚,罗鹏,等.牲畜粪便对草地生态系统影响的研究进展[J].生态学杂志,2009, 28(2):322-328.
[49]马玉寿,郎百宁,王启基.“黑土型”退化草地研究工作的回顾与展望[J].草业科学,1999,16(2): 5-9.
[50]李志昆.青海省高原草地生态系统退化的成因分析[J].养殖与饲料,2008,(5):68-71.
[51]王宝山,尕玛加,张玉.青藏高原“黑土滩”退化高寒草甸草原的形成机制和治理方法的研究进展[J].草原与草坪,2007,(2):72-77.
[52]周兴民.中国嵩草草甸[M].北京:科学出版社,2001.
[53]武高林,杜国祯.青藏高原退化高寒草地生态系统恢复和可持续发展探讨[J].自然杂志,2007,29(3):159-164.
[54] Liu X, Chen B. Climatic warming in the Tibetan Plateau during recent decades [J]. Int. J. Climatol., 2000, 20(14): 1729-1742.
[55] Klein J A, Harte J, Zhao X Q. Experimental warming causes large and rapid species loss, dampened by simulated grazing, on the Tibetan Plateau [J]. Ecology Letters, 2004, 7: 1170-1179.
[56]王根绪,李玉其,程国栋. 40年来江河源区气候变化特征及其生态环境效应[J].冰川冻土,2001,23(4):346-352.
[57] Du M, Shigeto K, Seiichiro Y, et al. Mutual influence between human activities and climate change in the Tibetan Plateau during recent years [J]. Global and Planetary Change, 2004,41: 241-249.
[58]白小明,蒲小鹏.金强河地区高寒草地气候变化分析[J].草业科学,2003,20(7):51-53.
[59] You Q, Kang, S, Aguilar E, et al. Changes in daily climate extremes in the eastern and central Tibetan Plateau during 1961–2005 [J]. Journal of Geophysical Research, 2008, 113 (d7): D07101-1-D07101-17.
[60]龙瑞军,董世魁,胡自治.西部草地退化的原因分析与生态恢复措施探讨[J].草原与草坪,2005,(6):3-7.
[61]张耀生,赵新全,周兴民.青海省草地畜牧业可持续发展战略与对策[J].自然资源学报,2000,15(4):328-334.
[62]周立志,李迪强,王秀磊,等.三江源自然保护区鼠害类型、现状和防治策略[J].安徽大学学报(自然科学版),2002,26(2):87-96.
[63]何昌茂.面向新世纪,牧区畜牧业要大发展——关于加快发展我国草原畜牧业几个问题的探讨[J].四川草原,2000,(2):1-6.
[64]王录仓江河源区草场退化的生态环境后果及成因[J].草业科学,2004,21(1):17-19.
[65]兰玉蓉.青藏高原高寒草甸草地退化现状及治理对策[J].青海草业,2004,13(1):27-30.
[66]何孝德,王薇娟.青海省草原毛虫分布区域及为害等级划分初探[J].草业科学,2003,20(8):45-47.
[67] Shiponeni N N, Milton S J. Seed dispersal in the dung of large herbivores: implications forrestoration of Renosterveld shrub land old fields [J]. Biodiversity and Conservation, 2006, 15: 3161-3175.
[68] Janzen D H. Herbivores and the number of tree species in tropical forest [J]. The American naturist, 1970, 104: 501-528.
[69] Janzen D H. Seed predation by animals [J]. Annual review of ecology and systematics, 1971, 2: 465-492.
[70] Nathan R, Muller-Landau H C. Spatial patterns of seed dispersal, their determinants and consequences for recruitment[J]. Trends in Ecology & Evolution, 2000, 15: 278-285.
[71] Willson M, Traveset A. 2000. The ecology of seed dispersal. In: Seeds: The ecology of regeneration in plant communities. 2 nd. Edition[M]. M. Fenner (ed.). Wallingford: CAB International. pp. 85–110.
[72]解兴词.阔叶红松林主要组成树种的种子扩散格局[D].东北林业大学硕士论文,2007.
[73] Harper J L. Population Biology of Plants [M]. London: Academic Press, 1977.
[74] Willson M F. Dispersal mode, seed shadows, and colonization patterns[J]. Plant Ecology, 1993, 261-280.
[75] Clark J S, Silman M, Kern R, et al. Seed Dispersal near and far: patterns across temperate and tropical forests[J]. Ecology, 1999, 80: 1475-1494.
[76] Hoekstra N J, Bosker T, Lantinga E A. Effects of cattle dung from farms with different feeding strategies on germination and initial root growth of cress (Lepidium sativum L.) [J]. Agriculture, Ecosystems and Environment, 2002, 93: 189-196.
[77] Nishi H, Tsuyuzaki S. Seed dispersal and seedling establishment of Rhus trichocarpa promoted by a crow (Corvus macrorhynchos ) on a volcano in Japan[J]. Ecography, 2004, 27: 311-322.
[78] Herrera C M, Jordano P, López-Soria L, et al. Recruitment of a mast-fruiting, bird-dispersed tree: bridging frugivore activity and seedling establishment[J]. Ecological Monographs, 1994, 64: 315-344.
[79]鲁长虎.动物对松属植物种子的传播作用研究进展[J].生态学杂志,2006,25(5):557-562.
[80] Couvreur M, Cosyns E, Hermy M, et al. Complementarity of epi- and endozoochory of plant seeds by free ranging donkeys[J]. Ecography, 2005, 28: 37-48.
[81] Debussche M, Isenmann P. Fleshy fruit characteristics and the choices of bird and mammal seed dispersers in a Mediterranean region[J]. Oikos, 1989, 56: 327-338.
[82] Amico G, and Aize M A. Mistletoe seed dispersal by a marsupial[J]. Nature, 2000, 408: 929-930.
[83] Tabarelli M, Peres C A. Abiotic and vertebrate seed dispersal in the Brazilian Atlantic forest: implications for forest regeneration[J]. Biol. Conserv.,2003, 106: 162-176.
[84] Welch D. Studies in the grazing of heather moorland in north-east Scotland [J]. J. Appl. Ecol., 1985, 22: 461-472.
[85] Gardener C J, McIvor J G, Jansen A. Passage of legume and grass seeds through the digestive tract of cattle and their survival in faces [J]. J. Appl. Ecol., 1993, 30: 63-74.
[86] Malo J E, Sua′rez F. Establishment of pasture species on cattle dung: the role of endozoochorous seeds [J]. J. Veg. Sci., 1995, 6: 169-174.
[87] Pakeman R J, Digneffe G, Small J L. Ecological correlates of endozoochory by herbivores [J]. Functional Ecology, 2002, 16: 296-304.
[88] Cosyns E. Ungulate seed dispersal. Aspects of endozoochory in a semi-natural landscape [D]. Ph.D. thesis, Ghent, Ghent Univ, 2004.
[89] Traveset A. Effect of seed passage through vertebrate frugivores' guts on germination: a review[J]. Perspectives in Plant Ecology, Evolution and systematics, 1998, 1(2): 151-190.
[90] Mouissie A M, Van Der Veen C E J, Veen G F C, et al. Ecological correlates of seed survival after ingestion by Fallow Deer [J]. Functional Ecology, 2005, 19, 284-290.
[91] Vellend M, Myers J A, Gardescu S, et al. Dispersal of Trillium seeds by deer: implications for long-distance migration of forest herbs [J]. Ecology, 2003, 84(4): 1067-1072.
[92] G?kbulak F. Effect of American bison (Bison bison L.) on the recovery and germinability of seeds of range forage species [J]. Grass and Forage Science, 2002, 57, 395-400.
[93] Espinar J L, García L V, Figuerola J, et al. Effects of salinity and ingestion by ducks on germination patterns of Juncus subulatus seeds [J]. Journal of Arid Environments, 2006, 66: 376-383.
[94] Ramos M E, Robles A B, Castro J. Efficiency of endozoochorous seed dispersal in six dry-fruited species (Cistaceae): from seed ingestion to early seedling establishment [J]. Plant Ecology, 2006, 185: 97-106.
[95] Cosyns E, Delporte A, Lens L, et al..Germination success of temperate grassland species after passage through ungulate and rabbit guts[J]. Journal of Ecology, 2005, 93: 353-361.
[96] Otani T. Effects of macaque ingestion on seed destruction and germination of a fleshy-fruited tree, Eurya emarginata[J]. Ecological Research, 2004, 19: 495-501.
[97] Ghassali F, Osman A E, Cocks P S. Rehabilitation of degraded grasslands in north Syria: the use of Awassi sheep to disperse the seeds of annual pasture legumes [J]. Experimental Agriculture,1998, 34: 391-405.
[98] Traba J, Levassor C, Peco B. Restoration of Species Richness in Abandoned Mediterranean Grasslands: Seeds in Cattle Dung [J]. Restoration Ecology, 2003, 11(3): 378-384.
[99] Myers J A, Vellend M, Gardescu S, et al. Seed dispersal by white-tailed deer: implications for long-distance dispersal, invasion, and migration of plants in eastern North America [J]. Oecologia, 2004, 139: 35-44.
[100] Milton S J, Dean W R. Seeds dispersed in dung of insectivores and herbivores in semi-arid southern Africa [J]. Journal of Arid Environments, 2001, 47: 465-483.
[101] Yamashiro A. Seed Dispersal by Kerama Deer (Cervus nippon keramae) on Aka Island, the Ryukyu Archipelago, Japan [J]. Biotropica, 2006, 38(3): 405-413.
[102]张学勇,杨允菲,亓娜,等.草食动物对结缕草种子散布及发芽力的影响[J].生态学杂志,2007,26(9):1491-1494.
[103]曹林.都江堰亚热带森林动物对樱桃果实/种子的捕食和扩散[D].四川大学硕士学位论文,2006.
[104]马瑞君,鲁先文,孙坤,等.灰喜鹊摄食对中国沙棘种子萌发的影响[J].西北植物学报,2005,25(3):472-477.
[105]唐占辉,盛连喜,马逊风,等.两种果蝠对光叶桑(Morus macroura)果实的取食及种子传播[J].生态学报,2007,27(5):1895-1902.
[106]申仕康,胡晓立,王跃华.鸟类对猪血木种子的散布及在其保护中的意义[J].广西植物,2008,28(5):650 -654.
[107]鲁先文,孙坤,马瑞君,等.鸟类取食中国沙棘果实的方式及其对种子的传播作用[J].生态学杂志,2005,24(6):635-638.
[108]余冠军,尹华宝,王贵林,等.鼬獾对枳椇种子选择和消化时间的研究[J].生物学杂志,2008,25(3):51-53,77.
[109]范朋飞,黄蓓,蒋学龙.云南无量山黑长臂猿对植物种子的传播作用[J].兽类学报,2008,28(3):232-236.
[110]匡崇义,徐驰,薛世明,等.亚热带牧用草地中威提特东非狼尾草的种子繁殖研究[J].四川草原,2004,10:8-10.
[111]达来,凹特根,占布拉,等.绵羊粪中排出的牧草种子及其发芽率研究[J].中国草地,1994,5:23-27.
[112] Trlica M J, Rittenhouse L R. Grazing and plant performance [J]. Ecological Applications, 1993, 3(1): 21-23.
[113] Noy-Meir I. Compensating growth of grazed plant and its relevance on the use of rangelands [J]. Ecological Applications, 1993, 13(1): 32-34.
[114]赵钢.草地畜牧业可持续发展刍议[J].内蒙古草业,1999,(2):1- 6.
[115]沈景林,谭刚,乔海龙,等.草地改良对高寒退化草地植被影响的研究[J].中国草地,2000,(5):49-54.
[116]汪诗平,李永宏,王艳芬,等.不同放牧率对内蒙古冷蒿草原植物多样性的影响[J].植物学报,2001,43(1):89-96.
[117]刘发央,徐长林,龙瑞军.牦牛放牧强度对金露梅灌丛草地群落物种多样性的影响[J].草地学报,2008,16(6):613-618.
[118]王启基,周兴民,张堰青,等.放牧对金露梅生长发育和生物量的影响[A].高寒草甸生态系统[C].北京:科学出版社,1991.
[119]董全民,马玉寿,李青云,等.牦牛放牧率对高寒小嵩草草甸植物群落的影响[J].中国草地,2004,26(3):24-32.
[120]董全民,赵新全,李青云,等.牦牛放牧率对小嵩草高寒草甸暖季草场植物群落组成和植物多样性的影响[J].西北植物学报,2005,25(1):94-102.
[121]盛海彦,曹广民,李国荣,等.放牧干扰对祁连山高寒金露梅灌丛草甸群落的影响[J].生态环境学报,2009,18(1):235-241.
[122]王仁忠.羊草种群能量生殖分配的研究[J].应用生态学报,2000,11(4):591-594.
[123]白哈斯.不同放牧率对草甸植被特征的影响[J].干旱区资源与环境,2008,22(4):170-174.
[124]仁青吉,罗燕江,王海洋,等.青藏高原典型高寒草甸退化草地的恢复——施肥刈割对草地质量的影响[J].草业学报,2004,13(2):43-49.
[125]王长庭,龙瑞军,王启兰,等.放牧扰动下高寒草甸植物多样性、生产力对土壤养分条件变化的响应[J].生态学报,2008,28(9):4144-4152.
[126]沈广爽,张明海,夏茜,等.放牧鹿科动物对植物群落结构及物种多样性的影响[J].家畜生态学报,2009,30(3):88-90.
[127]于应文.滩羊尿对陇东黄土高原草地植物生长和群落结构的影响[D].兰州大学博士学位论文,2005.
[128]于应文,南志标.畜尿排泄特征及其对草地植被和家畜选择采食的作用[J].生态学报,2008,28(2):777-785.
[129]郑阳,徐柱,锡林图雅,等.放牧强度对土—草—畜系统的影响研究进展[J].草原与草坪,2009,(5):72-76.
[130]姚爱兴,李平,王培,等.不同放牧制度下奶牛对多年生黑麦草/白三叶草地土壤特性的影响[J].草地学报,1995,4(2):65-102.
[131]戎郁萍,韩建国,王培,等.放牧强度对草地土壤理化性质的影响[J].中国草地,2001,23(4):41-47.
[132]张蕴薇,韩建国,李志强.放牧强度对土壤物理性质的影响[J].草地学报,2002,10(1):74-78.
[133]王玉辉,何兴元,周广胜.放牧强度对羊草草原的影响[J].草地学报,2002,10(1):45-49.
[134]范春梅,廖超英,李培玉,等.放牧对黄土高原丘陵沟壑区林草地土壤理化性状的影响[J].西北林学院学报,2006,21(2):1-4.
[135] Greenwood K L, Macleod D A, Hutchinson K J. Long-term stocking rate effects soil physical properties[J]. Aus. J. Exp. Agric, 1997, 37: 413-419.
[136]董全民,赵新全,马玉寿,等.江河源区披碱草和星星草混播草地土壤物理形状对牦牛放牧强度的响应[J].草业科学,2005,22(6):65-70.
[137]周丽艳,王明玖,韩国栋.不同强度放牧对贝加尔针茅草原群落和土壤理化性质的影响[J].干旱区资源与环境,2005,19(7):182-186.
[138]贾树海,王春枝,孙振涛,等.放牧强度和放牧时期对内蒙古草原上土壤压实效应的研究[J].草地学报,1999,7(3):217-221.
[139]姚爱兴,王培.不同放牧强度下奶牛对多年生黑麦草/三叶草地土壤特性的影响[J].草地学报,1995,3(3):181-189.
[140]朱绍宏.牦牛放牧强度对高寒草原植被群落及土壤养分影响的研究[D].甘肃农业大学硕士学位论文,2006.
[141]付华,王彦荣,吴彩霞,等.放牧对阿拉善荒漠草地土壤形状的影响[J].中国沙漠,2002, 22(4):339-343.
[142]蒋文兰,张英俊,符义坤,等.绵羊啃食和践踏对植物与草地物理形状的影响[J].草业学报,1999,8(增刊):82-89.
[143]红梅,陈有君,李艳龙,等.不同放牧强度对土壤含水量及地上生物量的影响[J].内蒙古农业科技,2001,(3):25-26.
[144]郑云玲,李雪松,张瑞,等.放牧强度对草原土壤与植被的影响[J].内蒙古农业大学学报,2008,29(1):262-266.
[145]裴海昆.不同放牧强度对土壤养分及质地的影响[J].青海大学学报(自然科学板),2004,22(4):29-31.
[146]干友民,李志丹,王钦,等.川西北亚高山草甸放牧退化演替研究[J].草地学报,2005,13(S1):48-52.
[147]李香真,陈佐忠.不同放牧率对草原植物与土壤C, N,P含量的影响[J].草地学报,1998,6(2):90-98.
[148] Reeder J D, Schuman G E. Influence of livestock grazing on C sequestration in semi-arid mixed grass and short grass rangelands [J]. Environmental Pollution, 2002, 116(3): 457-463.
[149] Frank A B,Tanaka D L, Hofmann L. Soil carbon and nitrogen of Northern Great Plains grasslands as influenced by long-term grazing [J]. Journal of Range Management,1995, 48: 470-474.
[150]王艳芬,陈佐忠,Larry T.人类活动对锡林郭勒地区主要草原土壤有机碳分布的影响[J].植物生态学报,1998,22(6):545-551.
[151]王淑强,胡直友,李兆方.同放牧强度对红三叶、黑麦草草地植被和土壤养分的影响[J].自然资源学报,1996,11(3):280-287.
[152]白可喻,王培,韩建国,等.放牧强度对新麦草人工草地氮素在牧草与土壤中的分配和动态的影响[J].草地学报,1999,7(1):46-53.
[153] Abbasi M K, Adams W A. Estimation of simultaneous nitrification and denitrification in grassland soil associated with urea-N using15Nand nitrification inhibitor [J]. Biol Fertil Soils, 2000, 31: 38-44.
[154] Milchunas D G, Laurenroth W K. Quantitative effects of grazing on vegetation and soil over a global range of environments [J]. Ecological Monographs, 1993, 63(4): 327-366.
[155] Valentina Z, Michael B, Meinhard A, et al. Impact of land-use change on nitrogen mineralization in subline grasslands in the Southern Alps [J]. Biol Fertil Soi1s, 2000, 31: 441-448.
[156]杨智明,王宁,张志强.放牧对草原生态系统的影响.Ⅰ放牧对草原土壤的影响[J].宁夏农学院学报,2004,25(1):70-72,95.
[157]王华静,徐留兴,葛成冉,等.放牧强度对草地土壤性状影响的研究进展[J].安徽农业科学,2008,36(34):15074-15075.
[158]格尔丹.西藏的牛粪文化[J].西藏民俗,2003,(1):44-47.
[159]张宗显.西藏的牛粪火俗[J].中国西藏(中文版),2004,(2):63-65.
[160] Rhode D, Madsen D B, Brantingham P J, et al. Yaks, yak Dung, and prehistoric human habitation of the Tibetan Plateau[J]. Developments in Quaternary Sciences, 2007, (9): 205-225.
[161]贾宽河.雪域牛粪[J].西藏民俗,2000,(1):46-47.
[162]罗红英,刘钟泽.西藏薪柴能源替代战略与总体规划的探讨[J].能源工程,2009,(3):14-18.
[163]鱼小军,蒲小鹏,黄世杰,等.蚂蚁对东祁连山高寒草地生态系统的影响[J].草业学报,2010,19(2):140-145.
[164]秦泗国.近50年气候变化对那曲地区环境承载力的影响[D].西藏大学硕士学位论文,2009.
[165]柳小妮.甘肃省草地蝗虫预测预报专家系统的研究与开发[D].甘肃农业大学博士学位论文,2003.
[166]张贵谦,保国俊,李文辉,等.甘肃高山细毛羊的适应性调查研究报告[J].中国养羊,1996,(1):4-5.
[167]鲍士旦.土壤农化分析(第三版)[M].北京:中国农业出版社,2000.
[168]陈锋,汪有奎,杨正国,等.祁连山森林草原可燃物种类数量及特征初步分析[J]. 2008,24(14):171-174.
[169]张德罡.东祁连山杜鹃灌丛生态系统研究[M].甘肃教育出版社,2003.
[170]尚斌.畜禽粪便热解特性试验研究[D].中国农业科学院硕士学位论文,2007.
[171]龙瑞军,徐长林,胡自治,等.天祝高山草原15种饲用灌木的热值及季节动态[J].生态学杂志,1993,12(5):l3-l6.
[172]于应文,胡自治,张德罡,等.天祝金强河高寒地区金露梅的热值及其季节动态[J].草业科学,2000,17(2):1-4.
[173]官丽莉,周小勇,罗艳.我国植物热值研究综述[J].生态学杂志,2005,24(4):452-457.
[174]许鹏.草地资源调查规划学[M].中国农业出版社,2000.
[175] Hakamata T, Hirashima T, Okumura J. Management of pasture in the cold region II: transfer of the nitrogen, phosphate, and potassium in dung to soil and forage[C]. Bull Hokkaido Report of Hokkaido Prefectural Agricultural Experiment Station, 1971, 24: 82-92
[176] Aarons S R, O’Connor C R, Gourley C J P. Dung decomposition in temperate dairypastures I. Changes in soil chemical properties[J]. Australian Journal of Soil Research, 2004, 42:107–114. doi: 10.1071/SR03008.
[177]李德志,高桥繁男,祝廷成.粪斑对结缕草放牧草地根系层土壤氮素的影响[J].应用与环境生物学报,2005,11(3):312-314.
[178]严学兵,汪玺,张德罡.放牧牦牛瘤胃生理指标的测定[J].黄牛杂志,2003,29(3):14-17.
[179] Aarons S R, O’Connor C R, Hosseini H M, et al. Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems [J]. Nutrient Cycling in Agroecosystems, 2008, DOI 10. 1007/s10705-008- 9228-5.
[180] Weeda W C. The effect of cattle dung patches on pasture growth, botanical composition, and pasture utilization [J]. New Zealand Journal of Agricultural Research, 1967, 10: 150-159.
[181] Haynes R J, Williams P H . Nutrient cycling and soil fertility in the grazed pasture ecosystem[J]. Advances in Agronomy, 1993, 49: 119-199.doi: 10. 1016 /S0065-2113 (08)60794-4.
[182]姜世成,周道玮.草原牛粪对牲畜取食影响的研究[J].中国草地,2002,24(1):41-46.
[183] Holter P . Effect of dung beetles and earthworms on the disappearance of cattle dung [J]. Oikos, 1979, 32, 393-402.
[184] Yokoyama K, Kai H, Koga T, et al. N mineralization and microbial populations in cow dung, dung balls and underlying soil affected by paracoprid dung beetles [J]. Soil Biology & Biochemistry, 1991,23: 649-953.
[185] Kaneda S, Yamashita N, Uchida T, et al. Effects of ivermectin in dung pats on earthworm (Megascolecidae) populations and pat degradation in Japanese grassland. [J] Applied Soil Ecology, 2006, 31: 280-285.
[186] Lovell RD, Jarvis SC. Effect of cattle dung on soil microbial biomass C and N in a permanent pasture soil[J]. Soil Biology & Biochemistry, 1996, 28(3): 291-299.
[187] Vona L C, Jung G A, Reid R L, et al. Nutritive value of worm-season grass hays for beef cattle and sheep: Digetbility, intake and mineral utilization[J]. Journal of animal science, 1984, 59: 1582-1593.
[188]陈友慷,袁有清,茂林,等.成年母牦牛冷季采食量和消化率测定[J].中国牦牛,1 994,(2):29-32,68.
[189]龙瑞军,董世魁,胡自治.同一日粮下泌乳牦牛与干奶牦牛消化代谢能力的比较研究[J].草业学报,1998,7(3):51-55.
[190]严学兵,汪玺,郭玉霞.放牧牦牛采食量和几种消化生理指标的测定[J].中国草食动物,2003,23(5):5-7.
[191]朱兴运.绵羊采食量和消化率测定方法简况(综述)[J].四川草原,1983,(1):93-97.
[192] Manzano P, Malo J E, Peco B. Sheep gut passage and survival of Mediterranean shrub seeds.[J] Seed Science Research, 2005, 15:21–28.
[193]周礼恺.土壤酶学[M].北京:科学出版社,1987.
[194]马克平,刘玉明.生物群落多样性的测度方法Ⅰa多样性的测度方法(上)[J].生物多样性,1994,2(3):162-168.
[195]马克平,刘玉明.生物群落多样性的测度方法Ⅱa多样性的测度方法(下) [J].生物多样性,1994,2(4):231-239.