Department of Horticulture, Sapientia University, Târgu-Mureş, Romania ; Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.
PLoS One. 2013 Aug 27;8(8):e73533. doi: 10.1371/journal.pone.0073533. eCollection 2013.
Traditional haymaking has created exceptionally high levels of plant species diversity in semi-natural grasslands of the Carpathian Mountains (Romania), the maintenance of which is jeopardized by recent abandonment and subsequent vegetation succession. We tested the hypothesis that the different life history strategies of dominant grasses cause different patterns of diversity loss after abandonment of traditional haymaking in two types of meadow. Although diversity loss rate was not significantly different, the mechanism of loss depended on the life history of dominant species. In meadows co-dominated by competitive stress-tolerant ruderals, diversity loss occurred following the suppression of dominant grasses by tall forbs, whereas in meadows dominated by a stress-tolerant competitor, diversity loss resulted from increased abundance and biomass of the dominant grass. We conclude that management for species conservation in abandoned grasslands should manipulate the functional turnover in communities where the dominant species is a weaker competitor, and abundance and biomass of dominant species in communities where the dominant species is the stronger competitor.
传统的干草制作在喀尔巴阡山脉（罗马尼亚）的半自然草原上创造了极高水平的植物物种多样性，但最近的废弃和随后的植被演替危及了这种多样性的维持。我们检验了这样一个假设，即在两种草地中，由于传统干草制作的废弃，优势草种的不同生活史策略会导致不同的多样性丧失模式。尽管多样性丧失率没有显著差异，但丧失的机制取决于优势种的生活史。在竞争压力耐受的杂草共同占主导地位的草地中，多样性的丧失是由于高大的野花对优势草种的抑制，而在以耐受压力的竞争者为主导的草地中，多样性的丧失则是由于优势草种的丰度和生物量增加所致。我们的结论是，对于废弃草地的物种保护管理，应该在优势种是较弱竞争者的群落中，操纵功能转换，而在优势种是较强竞争者的群落中，操纵优势种的丰度和生物量。
