Non-timber forest product harvesting in alien-dominated forests: effects of frond-harvest and rainfall on the demography of two native Hawaiian ferns
Non-timber forest product harvesting in alien-dominated forests: effects of frond-harvest and rainfall on the demography of two native Hawaiian ferns
复制标题
外来森林中的非木材林产品收获：叶状收获和降雨对两种夏威夷本土蕨类植物种群的影响
DOI：
10.1007/s10531-006-9030-0
复制
发表时间：
2007
影响因子：
3.4
通讯作者：
A. Nāmaka Whitehead
中科院分区：
文献类型：
--
作者：
T. Ticktin;Hōala Fraiola;A. Nāmaka Whitehead
非木材林产品 (NTFP) 对全世界数百万人来说是重要的文化和经济资源。尽管许多 NTFP 是从受干扰的栖息地收获的，因此受到多重压力，但很少有定量研究解决这个问题。同样，很少有 NTFP 研究评估了人口比率的季节性变化，尽管这可能会混淆收获效应。在夏威夷，野生蕨类植物、细鳞鳞蕨和中华蕨是非常重要的文化资源，但数量下降引起了保护问题。这两种蕨类植物都是从受干扰的、外来入侵物种占主导地位的森林中收获的，当代夏威夷的采集做法通常包括收获和同时除草外来入侵物种。我们通过比较实验收获与对照地块，并记录叶体人口统计模式与降水之间的关系，评估了同时进行叶体收获和外来物种除草对叶体结构、密度和生产率的影响。短期内采集做法对任一物种的叶密度或大多数其他人口统计参数都没有影响。例外情况包括，当在没有外来除草的情况下收集叶状体时，最长的中华五味子叶状体的密度显着下降，以及M. strigosa 叶状体产量的显着下降。然而，这两个物种的所有地块都发生了叶状密度和产量的季节性和年度变化，并且与降水量显着相关。这两个物种的收获效果相对较低可能是由于多种因素造成的，包括叶子寿命短以及采集者选择可收获叶子时使用的严格标准。讨论了在外来森林中可持续采伐的潜力。
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.