Shrubs facilitate recruitment of Caragana stenophylla Pojark: microhabitat amelioration and protection against herbivory

Key message: Mature Caragana stenophylla shrubs facilitated intraspecific sapling establishment by two mechanisms: microhabitat amelioration and protection against herbivory. Facilitation was mediated by climate, grazing and sapling age. Context: Pre-existing shrubs could facilitate sapling establishment of woody plants, however, how these facilitation vary across abiotic and biotic stress gradients and the underlying mechanisms remain unclear. Aims: The aim of this study is understanding the facilitation of shrub on sapling establishment, and how the two underlying mechanisms, microhabitat amelioration and protection against herbivory, vary across climatic aridity gradients, grazing gradients and sapling age. Methods: We conducted field sowing experiments to examine the facilitation of mature Caragana stenophylla Pojark on intraspecific sapling establishment. Results: Facilitation of C. stenophylla on sapling survival increased as drought stress, grazing intensity and sapling ...核心研究结论：成熟小叶锦鸡儿（Caragana stenophylla）灌丛通过两种机制促进种内幼苗定植：微生境改良与植食防护。该促进效应受气候、放牧强度及幼苗龄期调控。 研究背景：已有灌丛可促进木本植物幼苗定植，但此类促进效应如何随非生物与生物胁迫梯度变化，及其内在作用机制仍不明确。 研究目的：本研究旨在阐明灌丛对幼苗定植的促进效应，以及微生境改良、植食防护这两种核心内在机制如何随气候干旱梯度、放牧梯度及幼苗龄期发生变化。 研究方法：本研究通过野外播种实验，探究成熟小叶锦鸡儿（Caragana stenophylla Pojark）对其种内幼苗定植的促进效应。 研究结果：小叶锦鸡儿（C. stenophylla）对幼苗存活的促进效应随干旱胁迫、放牧强度及幼苗...