Spatial organisation of landscapes and its function in semi-arid woodlands, Australia
Spatial organisation of landscapes and its function in semi-arid woodlands, Australia
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DOI：
10.1007/bf00158553
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发表时间：
1995-02
影响因子：
5.2
通讯作者：
J. Ludwig;D. Tongway
中科院分区：
文献类型：
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作者：
J. Ludwig;D. Tongway
三个主要的景观类型内的半干旱林地的澳大利亚东部的空间组织进行了研究，通过详细的分析梯度为导向的样带（gradsects）。其目的是为了使每个景观的空间组织，并占该组织的功能相关的稀缺资源的差异集中可识别的过程。地形，植被和土壤数据收集沿着每个梯度。边界分析被用来确定在一系列尺度的景观单元的类型。土壤分析被用来确定这些单位内的养分浓度差的程度，并推断河流和风沙过程中保持它们的作用。所有三个主要的景观系统被发现是高度有组织的系统与独特的资源丰富的单位或补丁分开更开放，资源贫乏的地区。在最大的尺度上，明显的格罗夫斯树林被开放的中间格罗夫斯分隔开。在较小的尺度上，单个的树木、大灌木、灌木丛、倒下的原木和草丛构成了分散在整个景观中的离散斑块。我们的土壤分析证实，这些斑块通过过滤和集中从源区（例如，intergroves）。我们认为，河流径流径流和风成跃移沉积是参与这些浓度效应的物理过程，并在建设和维护补丁;生物活动也保持补丁。这种分散的资源过滤器（在不同尺度上）的斑块组织具有保护有限的资源在半干旱景观系统的整体功能。了解景观斑块在保护稀缺资源方面的作用，对于管理这些景观以实现可持续土地利用以及恢复已经退化的景观具有重要意义。
The spatial organisation of three major landscape types within the semi-arid woodlands of eastern Australia was studied by a detailed analysis of gradient-oriented transects (gradsects). The aim was to characterise the spatial organisation of each landscape, and to account for that organisation in functional terms related to the differential concentration of scarce resources by identifiable processes. Terrain, vegetation and soils data were collected along each gradsect. Boundary analysis was used to identify the types of landscape units at a range of scales. Soil analyses were used to determine the degree of differential concentration of nutrients within these units, and to infer the role of fluvial and aeolian processes in maintaining them. All three major landscape systems were found to be highly organised systems with distinctive resource-rich units or patches separated by more open, resource-poor zones. At the largest scale, distinct groves of trees were separated by open intergroves. At smaller-scales, individual trees, large shrubs, clumps of shrubs, fallen logs and clumps of grasses constituted discrete patches dispersed across the landscape. Our soil analyses confirmed that these patches act as sinks by filtering and concentrating nutrients lost from source areas (e.g., intergroves). We suggest that fluvial runoff-runon and aeolian saltation-deposition are the physical processes involved in these concentration effects, and in building and maintaining patches; biological activities also maintain patches. This organisation of patches as dispersed resource filters (at different scales) has the overall function of conserving limited resources within semi-arid landscape systems. Understanding the role of landscape patchiness in conserving scarce resources has important implications for managing these landscapes for sustainable land use, and for the rehabilitation of landscapes already degraded.