Herbivore and neighbour effects on tundra plants depend on species identity, nutrient availability and local environmental conditions
Herbivore and neighbour effects on tundra plants depend on species identity, nutrient availability and local environmental conditions
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DOI：
10.1111/j.1365-2745.2007.01322.x
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发表时间：
2008-01-01
影响因子：
5.5
通讯作者：
Eskelinen, Anu
中科院分区：
文献类型：
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作者：
Eskelinen, Anu
1. 我进行了一个因子移植实验，以测试在山地苔原环境中两种不同生境类型中植物-植物相互作用、哺乳动物食草性和资源可用性对植物性能的作用。以3种多年生双科草本植物金牛花（Solidago virgaurea）、鸢尾花（Erigeron uniflorus）和高山雪莲（Saussurea alpina）为研究对象，研究了邻居清除和放牧者排斥、营养富集和施肥对植物生长、存活和繁殖成功率的影响。这些处理在两种不同的生境类型，不育的酸性和肥沃的非酸性苔原石楠中重复进行。植物-植物相互作用对雪莲的影响从不育酸性生境的促进到肥沃非酸性生境和营养丰富条件下的竞争，而雪莲的整体性能受到食草动物的强烈负面影响，当植物受精和肥沃非酸性荒地时，这种影响更大。在营养丰富的条件下，灯盏花比在没有施肥的地块上生长得更好，而在没有施肥的地块上，邻居被移走了。放牧对黄花有负向影响，且营养丰富地块和非酸性荒原对黄花的影响大于酸性荒原和未施肥对照。在这3个物种中，邻居迁移和草食之间没有相互作用，表明这两个过程是独立运行的。在营养丰富的条件和天生肥沃的生境中，食草动物偏好的高大植物受到哺乳动物食草动物消耗的强烈限制。相比之下，在肥沃的栖息地和丰富的营养条件下，北极高山的专家和矮小的物种与邻近植被的竞争加剧了。合成。综上所述，冻土带植物群落中植物与植物、植物与食草动物相互作用的强度和方向取决于植物的物种特性，并受土壤因子的调节，从而控制植被过程。这些发现对于理解环境变化下贫瘠苔原生态系统中植被结构的力量具有重要意义。
1. I performed a factorial transplant experiment to test the roles of plant-plant interactions, herbivory by mammal grazers and resource availability for plant performance in two contrasting habitat types in a mountain tundra environment.2. Three perennial dicot herbs, Solidago virgaurea, Erigeron uniflorus and Saussurea alpina, were used as target plants to study the effects of neighbour removal and grazer exclusion, and nutrient enrichment and liming on plant growth, survival and reproductive success. These treatments were replicated in two contrasting habitat types, infertile acidic and fertile non-acidic tundra heaths.3. The effects of plant-plant interactions on Saussurea varied from facilitation in infertile acidic habitats to competition in fertile non-acidic habitats and in nutrient-enriched conditions, while the overall performance of Saussurea was strongly negatively influenced by the presence of grazers, the effects being greater when plants were fertilized and in fertile non-acidic heaths. Erigeron performed better under nutrient-enriched conditions than in unfertilized plots, when neighbours had been removed. Solidago was negatively affected by grazing and this impact was greater in nutrient-enriched plots and in non-acidic heaths than in acidic heaths and for unfertilized controls. There were no interactions between neighbour removal and herbivory in any of the three species, indicating that these processes operated independently.4. Grazer-preferred tall plants are strongly limited by consumption by mammal herbivores in nutrient-enriched conditions and in inherently fertile habitats. By contrast, arctic-alpine specialists and species of low stature experience increased competition with neighbouring vegetation in fertile habitats and in enriched nutrient conditions.5. Synthesis. Overall, the results suggest that the strength and directions of plant-plant and plant-herbivore interactions depend on plant species identity and are modified by soil edaphic factors to govern vegetation processes in tundra plant communities. These findings have important implications for understanding the forces structuring vegetation in barren tundra ecosystems under a changing environment.