Functional redundancy of multiple forest taxa along an elevational gradient: predicting the consequences of non-random species loss
Functional redundancy of multiple forest taxa along an elevational gradient: predicting the consequences of non-random species loss
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沿海拔梯度的多个森林类群的功能冗余：预测非随机物种丧失的后果
DOI：
10.1111/jbi.12514
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发表时间：
2015
影响因子：
3.9
通讯作者：
Gustafsson L
中科院分区：
文献类型：
--
作者：
Mori AS;Shiono T;Haraguchi TF;Ota AT;Koide D;Ohgue T;Kitagawa R;Maeshiro R;ToeToeAung;Nakamori T;Hagiwara Y;Matsuoka S;Ikeda A;Hishi T;Hobara S;Mizumachi E;Frisch A;Thor G;Fujii S;Osono T;Gustafsson L
气候变化可以极大地改变生态群落。然而，我们假设，即使出现了新的群落，这些群落在功能组成方面可能并不新颖。为了推断与温度升高相关的过程，我们评估了植物和无脊椎动物群落的海拔分类/功能转换。由于气候变化与其他环境因素具有协同作用，因此不是生态群落变化的唯一驱动因素，因此我们还考虑了哺乳动物过度放牧/浏览对群落分类/功能组成的影响，这在研究区域已成为突出的问题。地点：日本北海道知子半岛知子国立公园。方法对日本北部森林8个生物类群（分类群）的多样性进行调查，并计算其分类/功能相似性（Sørensen’s β‐多样性）沿海拔梯度的距离衰减。用一个零模型来区分功能性更替和分类学更替。然后，我们模拟了在对哺乳动物食草性敏感的物种非随机丧失后，沿着梯度的分类/功能转换将如何变化。结果各类群在分类相似性上呈现高度衰减。在海拔梯度上，由更强的扩散限制构成的物种类群表现出更快的物种更替。这表明不同种群在气候诱导的物种重组过程中存在差异。我们还发现，基于功能性状的群落的海拔更替倾向于低于基于分类同一性的群体，这支持了我们在海拔梯度上的功能冗余假设。因此，我们推测气候诱导的分类新群落的出现可能对功能多样性支持的关键生态系统过程的影响有限。此外，虽然随机物种损失不会改变功能转换，但由于哺乳动物食草性导致的非随机物种损失大大加速了该分类群的海拔功能转换。这表明可能会失去社区的功能冗余。未来的群落可能是新颖的，不仅因为气候正在以前所未有的速度变化，而且还因为其他环境变化的协同影响。因此，未来生态过程受到的影响可能比基于现有气候变化情景的一般预期更为严重，并可能对生态系统功能产生影响。
AimsClimate change can substantially alter ecological communities. However, we hypothesized that, even if novel communities emerge, those communities may not be novel in terms of functional composition. To infer the processes associated with rising temperatures, we evaluated elevational taxonomic/functional turnover of plant and invertebrate communities. Because climate change interacts synergistically with other environmental factors, and therefore is not the sole driver of change in ecological communities, we also considered how the taxonomic/functional composition of the communities would be affected by mammalian overgrazing/browsing, which has become prominent in the study region.LocationShiretoko National Park, Shiretoko Peninsular, Hokkaido, Japan.MethodsWe investigated the diversity of eight groups of organisms (taxa) in forests of northern Japan, and calculated the distance decay of taxonomic/functional similarity (Sørensen's β‐diversity) along an elevational gradient. A null model was used to separate functional turnover from taxonomic turnover. We then simulated how taxonomic/functional turnover along the gradient would be changed after non‐random loss of species sensitive to mammalian herbivory.ResultsWe found that each group showed elevational decay in taxonomic similarity. Along an elevational gradient, species groups structured by stronger dispersal limitation showed faster species turnover. This suggested differences in the process of climate‐induced species reassembly among the groups. We also found that elevational turnover of communities based on functional traits tended to be lower than that based on taxonomic identity for the majority of the groups, supporting our hypothesis of functional redundancy across the elevational gradient. We thus speculated that climate‐induced emergence of taxonomically novel communities may have limited influence on critical ecosystem processes supported by functional diversity. Furthermore, while random species loss did not change functional turnover, non‐random loss of species attributable to mammalian herbivory substantially accelerated elevational functional turnover of the taxa. This suggested a possible loss of the functional redundancy of communities.Main conclusionsFuture communities may be novel not simply because climates are changing at unprecedented rates but also because of the synergetic influences of other environmental changes. Thus ecological processes may be more seriously affected in the future than is generally anticipated based on existing climate‐change scenarios, with possible consequences for ecosystem functioning.