Degradation of Non-Photosynthetic Vegetation in a Semi-Arid Rangeland
Degradation of Non-Photosynthetic Vegetation in a Semi-Arid Rangeland
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DOI：
10.3390/rs8080692
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发表时间：
2016-08
期刊：
影响因子：
--
通讯作者：
H. Jackson;S. Prince
中科院分区：
文献类型：
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作者：
H. Jackson;S. Prince
旱地的土地退化是由于人为和自然原因而出现不良状况的过程。尽管退化具有特别有害的影响，而且具有潜在的不可逆转的性质，但区域评估在全球和区域两级提供了相互矛盾的退化程度、速度和严重程度。目前对退化的监测依赖于对植被的绿色、光合作用活跃部分（例如，叶子）。然而，关于退化对植被的非光合成分（例如，木材，茎，叶凋落物）和光合植被（PV）之间的关系，非光合植被（NPV），和退化条件下裸露的土壤（BS）。这项研究的主要目的是评价覆盖率的区域模式（即，PV，NPV，BS）在退化和非退化NPP条件下，在北昆士兰州，澳大利亚管理的牧场。确定了均匀的环境条件，并根据其潜在的参考值对NPP、PV、NPV和BS进行了缩放。我们发现，缩放NPP与缩放PV和缩放BS之间有很强的时空相关性。急剧的差异，也被发现为PV和BS之间的降解和非降解条件。NPV表现出与PV和BS的相似性，但无论降解条件如何，在所有区域均未发现NPV的明确关系。
Land degradation in drylands is the process in which undesirable conditions emerge due to human and natural causes. Despite the particularly deleterious effects of degradation, and it’s potentially irreversible nature, regional assessments have provided conflicting extents, rates, and severities of degradation, both globally and regionally. Current monitoring of degradation relies upon the detection of green, photosynthetically active parts of vegetation (e.g., leaves). Less is known, however, about the effect of degradation on the non-photosynthetic components of vegetation (e.g., wood, stems, leaf litter) and the relationship between photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), and bare soil under degraded conditions (BS). The major objective of the study was to evaluate regional patterns of fractional cover (i.e., PV, NPV, BS) under degraded and non-degraded NPP conditions in a managed rangeland in north Queensland, Australia. Homogenous environmental conditions were identified and each of NPP, PV, NPV, and BS were scaled according to their potential, reference values. We found a strong spatial and temporal correlation between scaled NPP with both scaled PV and scaled BS. Drastic differences were also found for PV and BS between degraded and non-degraded conditions. NPV displayed similarity to both PV and BS, however no clear relationship was found for NPV in all areas, irrespective of degradation conditions.