ABSTRACT

The diversity and population structure of woody species at Maun Educational Park (MEP) was investigated from June to July 2018. A total of 23, 18 and 30 quadrats of 20 × 20 m size were laid down at 50 m intervals along a transect line at riparian, seasonal floodplain and upland habitat, respectively. The Shannon diversity index and evenness were 1.87 and 1.54 in the riparian habitat, 2.01 and 0.77 in the seasonal floodplain habitat, 0.71 and 0.80 in the upland habitat. The species richness was 22, 14 and 19 in riparian, seasonal floodplain and upland habitat, respectively. The patterns of population structures of the woody species revealed that 32% and 21% of the woody species recorded in riparian and upland habitat, respectively, had a “reverse J-shaped” distribution, indicating a healthy or good regeneration. Vachellia tortilis and Combretum imberbe showed healthy regeneration in both riparian and upland habitat. Healthy regeneration in these species was attributable to their adaptive and defence mechanisms to herbivory. Most of the woody species showed either hampered seedling recruitment or hampered regeneration as a result of anthropogenic disturbance and herbivory. Almost all of the woody species (86%) in the seasonal floodplain habitat exhibited relatively good seedling recruitment and discontinued regeneration in the subsequent middle and higher diameter classes, suggesting that flooding inhibited regeneration of woody species.

摘要

于2018年6月至2018年7月，对Maun教育公园（MEP）的木本物种多样性和种群结构进行了调查。在20m×20 m大小的样方中，沿着样带线以50 m的间隔共放置了23、18和30个四方类动物。河岸，季节性洪泛区和高地栖息地。河岸生境的香农多样性指数和均匀度分别为1.87和1.54，季节性洪泛平原生境的香农多样性指数和均匀度分别为2.01和0.77，高地生境的香农多样性指数和均匀度为0.71和0.80。河岸带，季节性洪泛区和高地生境的物种丰富度分别为22、14和19。木本物种的种群结构格局表明，在河岸和高地栖息地记录的木本物种分别有32％和21％具有“反J形”分布，表明健康或良好的再生。Vachellia tortilis和Combretum imberbe在河岸和高地栖息地均显示出健康的再生。这些物种的健康再生归因于它们对草食动物的适应和防御机制。大多数木本物种由于人为干扰和食草而显示出幼苗受阻或再生受阻。季节性洪泛区生境中几乎所有木本物种（86％）在随后的中径和大径类中均表现出相对较好的幼苗募集和再生中断，表明洪水抑制了木本物种的再生。