Department of Geography, University of Florida, P.O. Box 117315 3124, Turlington Hall, Gainesville, FL 32611-7315, USA.
Environ Manage. 2011 Aug;48(2):237-47. doi: 10.1007/s00267-010-9579-y. Epub 2010 Nov 16.
Comparative studies on plant species richness, endemism, floristic composition, and structure between protected and unprotected forests are few in the Eastern Arc Mountains, one of the most biodiverse ecosystems in Africa. This study from one mountain range, the East Usambaras, examines floristic and structural tree data from 41-0.5 ha plots in four types of Eastern Arc forest: active agroforests, recently abandoned agroforests, mature secondary forest, and natural forest. Active agroforests had significantly lower tree species richness, endemic species richness, and stand density compared to natural and mature secondary forest. Recently abandoned agroforests contained a higher tree species richness, density, and tree height than active agroforests. Active and abandoned agroforests were dominated by an invasive tree, Maesopsis eminii. This tree species makes up a large percentage of the stems in active agroforests (26%), recently abandoned agroforests (32%), and in the canopy of mature secondary forests ∼ 30 years post logging (30%). Through time the increasing dominance of this non-native tree in active agroforests is a concern when considering the role of agroforests in a landscape scale conservation strategy.
在东非大裂谷（非洲生物多样性最丰富的生态系统之一），关于受保护和不受保护森林之间植物物种丰富度、特有性、植物区系组成和结构的比较研究很少。本研究来自东非大裂谷的一个山脉——东乌桑巴拉山脉，考察了 4 种东非大裂谷森林（活跃的农林复合系统、最近废弃的农林复合系统、成熟次生林和自然林）中 41-0.5 公顷样地的植物区系和结构树木数据。与自然林和成熟次生林相比，活跃的农林复合系统的树种丰富度、特有种丰富度和林分密度显著较低。最近废弃的农林复合系统的树种丰富度、密度和树高均高于活跃的农林复合系统。活跃和废弃的农林复合系统以一种入侵树种 Maesopsis eminii 为主。该树种在活跃的农林复合系统（26%）、最近废弃的农林复合系统（32%）和采伐后约 30 年的成熟次生林树冠层中占很大比例（30%）。随着时间的推移，这种非本地树种在活跃的农林复合系统中日益占据主导地位，这引起了人们对农林复合系统在景观尺度保护策略中的作用的关注。
