Management intensity and temporary conversion to other land-use types affect plant diversity and species composition of subtropical grasslands in southern Brazil
Management intensity and temporary conversion to other land-use types affect plant diversity and species composition of subtropical grasslands in southern Brazil
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DOI：
10.1111/avsc.12262
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发表时间：
2016-10-01
影响因子：
2.8
通讯作者：
Kollmann, Johannes
中科院分区：
文献类型：
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作者：
Koch, Christiane;Conradi, Timo;Kollmann, Johannes
我们研究了草地管理强度和临时退耕对亚热带草地非生物和生物特性的影响。以物种丰富的中等经营强度永久草地(PG-M)为参照，提出如下问题：(1)低强度和高强度永久草地(PG-L和PG-H)的植物多样性和物种组成是否与对照草地不同；(2)退耕还草(SG-A)或人工松林(SG-P)草地的植物种类组成和非生物条件是否与永久性草地不同？高地草原、塞拉高原、南里奥格兰德河(RS)草地。利用指示种分析确定不同土地利用类型的特征物种。结果PG-L和PG-H在植物种类组成上均与PG-M不同。尽管PG-L和PG-M有许多典型的草原物种，但它们的群落多样性普遍较低。另一方面，PG-H不仅种类较少，而且在种类组成上与PG-M有所偏离。原耕地和人工林的次生草地物种组成与PG-M不同，多样性较低。SG-P与PG-L和PG-M的土壤条件相似，但与PG-H和SG-A的土壤条件不同。结论所有土地利用类型均偏离基准草地。如果重新引入传统管理强度，PG-L中物种数量的减少可能会逆转，而SG-P中强烈的成分变化可能需要重新引入草地物种。PG-H和SG-A的情况也是如此：在生物和非生物成分方面，两者都显示出与参考草地的显著偏离。总体而言，将改变的土地利用类型恢复到接近自然的亚热带草原似乎是可行的，但必须开发适当的技术。
QuestionsWe investigated the effects of grassland management intensity and temporary conversion to other land uses on abiotic and biotic properties of subtropical grasslands. We used species-rich permanent grasslands of medium management intensity (PG-M) as a reference, and asked the following questions: (1) do permanent grasslands with low and high management intensities (PG-L and PG-H, respectively) have different plant diversity and species composition than reference grasslands; and (2) do secondary grasslands recovering from conversion to arable fields (SG-A) or pine plantations (SG-P) differ from permanent grasslands in their plant species composition and abiotic conditions?LocationHighland grasslands, Campos de Cima da Serra, Rio Grande do Sul (RS), Brazil.MethodsWe analysed variation in plant species composition and diversity among 80 grassland sites, including three types of permanent grassland and two types of secondary grassland. An indicator species analysis was used to identify characteristic species for the different land-use types. We used a linear discriminant analysis to investigate differences in soil conditions among land-use types.ResultsBoth PG-L and PG-H differed from PG-M regarding plant species composition. Although PG-L shared many typical grassland species with PG-M, their communities were generally less diverse. PG-H, on the other hand, not only had fewer species but also deviated from PG-M in species composition. Secondary grasslands on former arable fields and plantations differed from PG-M in species composition and showed lower diversity. Soil conditions of SG-P were similar to those of PG-L and PG-M, but they were distinct from those of PG-H and SG-A.ConclusionsAll land-use types showed deviations from reference grasslands (PG-M). The decrease in the number of species in PG-L may be reversed if traditional management intensity is re-introduced, whereas strong compositional changes in SG-P may require the re-introduction of grassland species. This is also true for PG-H and SG-A: both showed marked deviations from reference grasslands in biotic and abiotic components. Overall, restoration of altered land-use types to near-natural subtropical grassland seems feasible, but suitable techniques have to be developed.