Calbi Mariasole, Fajardo-Gutiérrez Francisco, Posada Juan Manuel, Lücking Robert, Brokamp Grischa, Borsch Thomas
Botanischer Garten und Botanisches Museum Berlin Freie Universität Berlin Berlin Germany.
Institut für Biologie - Systematische Botanik und Pflanzengeographie Freie Universität Berlin Berlin Germany.
Ecol Evol. 2021 Feb 1;11(5):2110-2172. doi: 10.1002/ece3.7182. eCollection 2021 Mar.
High Andean forests harbor a remarkably high biodiversity and play a key role in providing vital ecosystem services for neighboring cities and settlements. However, they are among the most fragmented and threatened ecosystems in the neotropics. To preserve their unique biodiversity, a deeper understanding of the effects of anthropogenic perturbations on them is urgently needed. Here, we characterized the plant communities of high Andean forest remnants in the hinterland of Bogotá in 32 0.04 ha plots. We assessed the woody vegetation and sampled the understory and epiphytic cover. We gathered data on compositional and structural parameters and compiled a broad array of variables related to anthropogenic disturbance, ranging from local to landscape-wide metrics. We also assessed phylogenetic diversity and functional diversity. We employed nonmetric multidimensional scaling (NMDS) to select meaningful variables in a first step of the analysis. Then, we performed partial redundancy analysis (pRDA) and generalized linear models (GLMs) in order to test how selected environmental and anthropogenic variables are affecting the composition, diversity, and aboveground biomass of these forests. Identified woody vegetation and understory layer communities were characterized by differences in elevation, temperature, and relative humidity, but were also related to different levels of human influence. We found that the increase of human-related disturbance resulted in less phylogenetic diversity and in the phylogenetic clustering of the woody vegetation and in lower aboveground biomass (AGB) values. As to the understory, disturbance was associated with a higher diversity, jointly with a higher phylogenetic dispersion. The most relevant disturbance predictors identified here were as follows: edge effect, proximity of cattle, minimum fragment age, and median patch size. Interestingly, AGB was efficiently predicted by the proportion of late successional species. We therefore recommend the use of AGB and abundance of late successional species as indicators of human disturbance on high Andean forests.
安第斯山脉高处的森林拥有极高的生物多样性，在为周边城市和定居点提供至关重要的生态系统服务方面发挥着关键作用。然而，它们是新热带地区最破碎化且受威胁的生态系统之一。为了保护其独特的生物多样性，迫切需要更深入地了解人为干扰对它们的影响。在此，我们在波哥大腹地32个0.04公顷的样地中，对安第斯山脉高处森林残余地的植物群落进行了特征描述。我们评估了木本植被，并对林下植被和附生植物覆盖情况进行了采样。我们收集了有关组成和结构参数的数据，并编制了一系列与人为干扰相关的变量，范围从局部到景观尺度的指标。我们还评估了系统发育多样性和功能多样性。在分析的第一步，我们采用非度量多维标度法（NMDS）来选择有意义的变量。然后，我们进行了偏冗余分析（pRDA）和广义线性模型（GLM），以测试所选的环境和人为变量如何影响这些森林的组成、多样性和地上生物量。已识别的木本植被和林下植被群落的特征在于海拔、温度和相对湿度的差异，但也与不同程度的人类影响有关。我们发现，与人类相关的干扰增加导致系统发育多样性降低，木本植被的系统发育聚类以及地上生物量（AGB）值降低。至于林下植被，干扰与更高的多样性以及更高的系统发育离散度相关。此处确定的最相关的干扰预测因子如下：边缘效应、牛群的接近程度、最小片段年龄和斑块中位大小。有趣的是，AGB可以通过后期演替物种的比例有效地预测。因此，我们建议使用AGB和后期演替物种的丰度作为安第斯山脉高处森林人为干扰的指标。
