Effect of plant species richness on invasibility of experimental plant communities
Effect of plant species richness on invasibility of experimental plant communities
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DOI：
10.1007/s11258-008-9401-6
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发表时间：
2008-10-01
期刊：
影响因子：
1.7
通讯作者：
Leps, Jan
中科院分区：
文献类型：
--
作者：
Lanta, Vojtech;Leps, Jan
摘要通过3年的野外试验，研究了未播种物种对人工草地物种群落的入侵情况。实验中，在对照和施肥地块上种植不同物种丰富度（1、2、4、8和16种）和功能群丰富度（1-4，禾草、豆科、莲座叶和匍匐叶）的植物组合，不试图阻止未播种物种的入侵或对其进行除草。在2003年、2004年和2005年三个研究年份，播种种的物种多样性、功能群多样性与地上生物量呈显著正相关。后2年，杂草入侵生物量随播种物种生物量和功能群丰富度的增加而显著减少，但不随物种数量的增加而减少。然而，除了居民生物量的增加外，物种和功能群丰富度没有明显的抑制作用。事实上，物种丰富度的正偏效应虽小但显著，表明相同数量的常驻生物量对入侵生物的负影响在物种较少的情况下更强。居民功能类群数量与入侵生物量呈负相关关系，说明功能性状空间覆盖度的提高可能是促进居民抵抗入侵的机制之一。此外，入侵植物的种类组成与播种居民的初始组成显著相关。
Invasion of unsown species to artificially created assemblages of grassland species was investigated in a 3-year field experiment. In the experiment, assemblages varying in species richness (1, 2, 4, 8, and 16 species) and functional group richness (1-4, grasses, legumes, rosette forbs, and creeping forbs) were grown in control and fertilized plots, without any attempt to prevent the invasion of unsown species or to weed them. The relationship between species and functional group diversity and above-ground biomass was positive for sown species in all study years (2003, 2004 and 2005). In the latter 2 years, weed invader biomass decreased significantly with increasing biomass of sown species and their functional group richness, but not with number of species. However, no suppressive effect of species or functional group richness beyond that by increased biomass of residents was found. In fact, slight but significant positive partial effect of species richness was found, suggesting that the negative effect of the same amount of resident biomass on invaders is stronger when the biomass is composed of fewer species. The negative relationship between the number of functional groups of residents and invader biomass suggested that better coverage of functional trait space could be a mechanism promoting the resistance to invasion. In Addition, species composition of invaders were significantly related to initial composition of sown residents.