Recovery of pasture production and soil properties on soil slip scars in erodible siltstone hill country, Wairarapa, New Zealand
Recovery of pasture production and soil properties on soil slip scars in erodible siltstone hill country, Wairarapa, New Zealand
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新西兰怀拉拉帕可侵蚀粉砂岩丘陵地区的牧场生产和土壤特性在土壤滑痕上的恢复
DOI：
10.1080/00288233.2010.535489
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发表时间：
2011
影响因子：
1.8
通讯作者：
C. Ross
中科院分区：
文献类型：
--
作者：
B. Rosser;C. Ross
摘要：对先前（1977 年、1961 年和 1941 年）以及 1984 年为牧场生产和表土特征进行采样的滑坡疤痕进行了重新采样。从 2007 年开始，对相同的伤痕和未侵蚀的对照地点的牧草干物质 (DM) 产量和选定的土壤特性进行了重新测量，为期两年。结果表明，经过 25 年的恢复，1941 年和 1961 年的滑痕处牧草产量没有出现显着增加。侵蚀场地的平均 DM 牧草产量从未侵蚀场地牧草产量水平的 63% 增加到 78%，但改善仅限于最年轻的 1977 年滑痕，那里的 DM 产量从未侵蚀水平的 20% 增加到 80%。回归分析显示，最大牧场恢复发生在滑坡发生后约 20 年内，进一步恢复超过未侵蚀水平 80% 的可能性不大。滑痕上牧草产量的恢复遵循与土壤物理（例如土壤深度、颗粒密度、容重）和化学性质（例如总碳、总氮）类似的恢复。侵蚀地点的表土深度大约是未侵蚀地点表土深度的三分之一，表明侵蚀土壤的剖面可用水容量减少。这项研究无法确定总碳是否会恢复到未侵蚀的水平，因为侵蚀地点的总碳变化很大。然而，考虑到原始森林下形成了未侵蚀的土壤（在很长一段时间内），而牧场下正在形成新的土壤（在短时间内），总碳不太可能恢复到未侵蚀土壤的水平。这项研究验证了 1984 年开展的先前工作的结论，即在人类时间尺度内，滑痕上的牧场生产不太可能恢复到未侵蚀地区的生产水平。由于累积侵蚀导致牧场产量逐渐减少，软岩山地陡峭山坡上的畜牧农业的可持续性日益受到威胁。
Abstract Landslide scars previously dated (1977, 1961 and 1941) and sampled in 1984 for pasture production and topsoil characteristics were re-sampled. Pasture dry matter (DM) production and selected soil properties were re-measured on the same scars and uneroded control sites for 2 years, beginning in 2007. The results show that after a further 25 years of recovery, no significant increase in pasture production had occurred on the 1941 and 1961 slip scars. Average DM pasture production on eroded sites increased from 63 to 78% of pasture production levels on uneroded sites, but improvement was restricted to the youngest 1977 slip scars, where DM production increased from 20 to 80% of uneroded levels. Regression analysis revealed that maximum pasture recovery occurred within about 20 years of landsliding and further recovery beyond 80% of uneroded level was unlikely. The recovery of pasture production on slip scars follows similar recovery to soil physical (e.g. soil depth, particle density, bulk density) and chemical properties (e.g. total C, total N). Topsoil depths on eroded sites were roughly a third of topsoil depths on uneroded sites, indicating reduced profile available water capacity on eroded soils. This research was unable to determine if total C would recover to uneroded levels because of the high variability in total C at eroded sites. However, given that uneroded soils were formed under native forest (over a long period of time) and that new soils are forming under pasture (over a short period of time), it is unlikely that total C will recover to uneroded soil levels. This research verifies the conclusion of the previous work carried out in 1984 that it is unlikely pasture production on slip scars will return to production levels on uneroded sites in human timescales. The sustainability of pastoral agriculture on steeper slopes in soft-rock hill country is increasingly under threat from the progressive reduction of pasture production from cumulative erosion.