Effect of drought and nutrient availability on invaded plant communities in a semi-arid ecosystem

Ecosystem functions are heavily dependent on the functional composition of the plant community, i.e., the functional traits of plants forming the community. This, on the one hand, depends on plant occurrence, but on the other hand depends on the intraspecific variability of functional traits of the species, which are influenced by climate and nutrient availability and affected by plant-plant interactions. To illustrate that, we studied the effects of drought and nitrogen addition (+ N), two important abiotic variables which are changing with ongoing global change, as well as their combined effect on the functional responses of grassland communities in semi-arid environments of Northern Africa comprising of natural and invasive species. We conducted a plot plant experiment where we planted three native species and one invasive plant species in artificial communities as of 5 individuals per species per plot. We exposed these communities to four different treatments: a drought treatment, a...

生态系统功能高度依赖植物群落的功能组成，即构成该群落的植物所具备的功能性状（functional traits）。这一组成一方面取决于植物的种群发生情况，另一方面则取决于各物种种内功能性状的变异水平；这类变异既受气候与养分有效性的调控，同时也会受到植物间相互作用的影响。为阐明这一机制，我们针对北非半干旱环境下由本土物种与入侵物种构成的草原群落开展了研究，聚焦于干旱与氮素添加（+N）这两种随全球持续变化而发生改变的关键非生物变量（abiotic variables），以及二者的交互效应对群落功能响应的影响。我们设置了样地栽培实验：在人工构建的植物群落中，每个样地内定植3个本土物种与1个入侵植物物种，每个物种的种植密度为每样地5个个体。我们将这些人工群落置于四种不同的处理条件下：干旱处理、……