Ungulate exclusion and tree community database

The dataset presents data collected from an inventory of trees and shrubs in a novel experimental layout to investigate the contrasting effects of ungulate herbivory on woody vegetation in nutrient-rich versus nutrient-poor sites (i.e. termite mounds versus off-mound sites with and without large mammalian herbivores) from Lake Mburo National Park in western Uganda. We hypothesized that (1) the resource-rich plots (i.e. termite mounds) would have a higher woody plant species richness and diversity (Støen et al., 2013; Joseph et al., 2015), and a lower evenness (Støen et al., 2013) compared to the resource-poor adjacent savanna matrix, while ungulate exclusion would not affect these diversity measures on any treatment (Støen et al., 2013; Joseph et al. 2015); (2) within-treatment beta-diversity would be higher on the off-mound areas compared with termite mounds and decrease with ungulate exclusion on the off-mound areas only (Støen et al., 2013); (3) woody plant assemblages on resource-rich mounds would be more similar than the resource-poor savanna matrix areas and herbivory would reduce contrasts between mound and matrix sites (Seymour et al., 2016). Findings from the analyzed data indicated that excluding large herbivores had little discernible effect on the species richness and plot-level diversity of woody species on nutrient-rich mounds but increased both richness and diversity on the relatively nutrient-poor off-mound sites. We conclude that ungulates reduce woody species diversity in resource-poor savanna areas but have little influence in resource-rich areas.本数据集源自乌干达西部姆布罗湖国家公园内一项全新实验设计下的乔灌木清查数据，旨在探究有蹄类啃食（ungulate herbivory）对营养富集生境与营养匮乏生境中木本植被（woody vegetation）的差异化影响——两类生境分别为白蚁丘（termite mounds），以及存在/不存在大型哺乳动物啃食的丘外生境（off-mound sites）。本研究提出如下假说：（1）相较于毗邻的营养匮乏稀树草原基质（savanna matrix）生境，营养富集样地（即白蚁丘）的木本植物物种丰富度与多样性更高（Støen等，2013；Joseph等，2015），而物种均匀度更低（Støen等，2013）；且有蹄类禁牧（ungulate exclusion）不会对任意处理组的上述多样性指标产生影响（Støen等，2013；Joseph等，2015）；（2）相较于白蚁丘生境，丘外区域的处理组内β多样性（beta-diversity）更高，且仅在丘外区域中，有蹄类禁牧会降低该β多样性（Støen等，2013）；（3）营养富集的白蚁丘生境中木本植物群落组成相较于营养匮乏的稀树草原基质生境更为相似，且啃食作用会缩小白蚁丘与基质生境之间的群落差异（Seymour等，2016）。数据分析结果显示，对营养富集的白蚁丘生境中的木本植物而言，移除大型有蹄类对其物种丰富度与样地水平多样性几乎无显著影响；但在相对营养匮乏的丘外生境中，该处理同时提升了物种丰富度与多样性。综上，有蹄类啃食会降低营养匮乏稀树草原区域的木本植物物种多样性，但对营养富集区域几乎无影响。