Non-timber forest product harvesting in alien-dominated forests: effects of frond-harvest and rainfall on the demography of two native Hawaiian ferns
详细信息 查看全文
- 作者：Tamara Ticktin ; H¨ala Fraiola and A. N¨¡maka Whitehead
- 关键词：Demography ; Ferns ; Hawaiȁ ; 8i ; Invasive species ; Microlepia strigosa ; Non ; timber forest products ; Sustainable harvest ; Sphenomeris chinensis
- 刊名：Biodiversity and Conservation
- 出版年：2007
- 出版时间：June, 2007
- 年：2007
- 卷：16
- 期：6
- 页码：1633-1651
- 全文大小：304 KB
文摘
Non-timber forest products (NTFP) represent culturally and economically important resources for millions of people worldwide. Although many NTFP are harvested from disturbed habitats and therefore subject to multiple pressures, few quantitative studies have addressed this issue. Similarly few NTFP studies have assessed seasonal variation in demographic rates even though this can confound harvest effects. In Hawaiȁ8i, the wild-gathered ferns, Microlepia strigosa and Sphenomeris chinensis, represent highly important cultural resources but declining populations have led to conservation concerns. Both ferns are harvested from disturbed, alien-dominated forests and contemporary Hawaiian gathering practices often consist of harvest and concurrent weeding of alien invasive species. We assessed the effects of concurrent frond-harvest and alien species weeding on frond structure, density, and rates of production by comparing experimentally harvested vs. control plots, and documented relationships between frond demographic patterns and precipitation. Gathering practices had no impact on frond density of either species or on most other demographic parameters over the short term. Exceptions included a significant decrease in the density of the longest S. chinensis fronds and a significant decrease in M. strigosa frond production when fronds were gathered without alien weeding. However, seasonal and annual changes in frond density and production occurred across all plots of both species and were significantly correlated with precipitation. The relatively low harvest effects for both species are likely due to several factors including short frond longevity and the strict criteria used by gatherers to select harvestable fronds. The potential for sustainable harvest in the context of alien-dominated forests is discussed.