Recovery of Mediterranean steppe vegetation after cultivation: Legacy effects on plant composition, soil properties and functional traits
Recovery of Mediterranean steppe vegetation after cultivation: Legacy effects on plant composition, soil properties and functional traits
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DOI：
10.1111/avsc.12415
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发表时间：
2019-01-01
影响因子：
2.8
通讯作者：
Roemermann, Christine
中科院分区：
文献类型：
--
作者：
Helm, Juliane;Dutoit, Thierry;Roemermann, Christine
休耕地35年后的植被结构和土壤性质是否与邻近物种丰富的地中海草原群落相似？在重新引入传统放牧系统后，是否会自发地对原始草原植被进行再开发？不同土地利用类型能否区分功能性状组成的差异？被选择物种的特征是否会影响它们在休耕地重新定居的能力？地理位置：拉克劳（法国东南部）的地中海草原。方法2015年在拉克劳6个地点的草原及邻近休耕地进行80次植被调查和土壤分析；三个地点的数据包括2001年的数据。为了比较草原与休闲地的功能组成，计算了群落加权平均比叶面积（SLA）、叶片干物质含量（LDMC）和冠层高度。为了验证性状变异是否与12个选择的目标物种的再定殖成功相关，我们测量了每个地点和物种的8个重复个体的SLA、LDMC、冠层高度、植物宽度和地上生物量。结果休耕地物种丰富度较低，土壤磷、钾含量较高。对比2001 - 2015年的植被高度，发现休耕地正在向草原植被发展。草原区低密度密度的CWM显著低于休耕地，低密度密度的CWM显著高于休耕地。成功再定居的草原物种之间的性状组成没有相似性，也没有证据表明种内性状变异与这些物种的再定居成功有关。结论经过几十年的撂荒和复牧，休耕地的植被结构、土壤性质和植物功能性状组成与邻近草原群落存在差异。这些结果表明，有必要采取积极的恢复措施，加快原耕地向目标草原群落的恢复。
Questions Are the vegetation structure and soil properties of fallows similar to adjacent species-rich Mediterranean steppe communities 35 years after abandonment? Is there a spontaneous redevelopment towards the original steppe vegetation after reintroduction of the traditional grazing system? Can differences in functional trait composition be identified according to different land-use types? Do traits of selected species affect the ability to recolonize fallow land? Location Mediterranean steppe of La Crau (Southeastern France). Methods We conducted 80 vegetation surveys and soil analyses in the steppe and adjacent fallow land in six locations in La Crau in 2015; for three locations, data from 2001 were included. To compare the functional composition of steppe vs fallow land, community-weighted means (CMW) of specific leaf area (SLA), leaf dry matter content (LDMC) and canopy height were calculated. To test whether trait variability is associated with the recolonization success of 12 selected target species, we measured SLA, LDMC, canopy height, plant width and aboveground biomass on eight replicate individuals per site and species. Results Fallow land was characterized by lower species richness and elevated phosphorus and potassium content in the soil. Comparing vegetation releves between 2001 and 2015 revealed that the fallows were developing towards steppe vegetation. CWMs of SLA were significantly lower and CWM of LDMC higher in steppe than in fallow land. There was no similarity in trait composition between steppe species that successfully recolonized the fallow-land community, and no evidence that intraspecific trait variability is associated with recolonization success of these species. Conclusions Even after decades of abandonment and reintroduction of the grazing system, the vegetation structure, soil properties and plant functional trait composition of fallows differ from those of adjacent steppe communities. These results illustrate the need for active restoration to accelerate the recovery of former arable land to the target steppe communities.