Robinson David A, Nemes Attila, Reinsch Sabine, Radbourne Alan, Bentley Laura, Keith Aidan M
UK Centre for Ecology & Hydrology, Environment Centre Wales, Bangor, United Kingdom.
Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.
Sci Total Environ. 2022 Dec 15;852:158506. doi: 10.1016/j.scitotenv.2022.158506. Epub 2022 Sep 2.
Global land use change has resulted in more pasture and cropland, largely at the expense of woodlands, over the last 300 years. How this change affects soil hydraulic function with regard to feedbacks to the hydrological cycle is unclear for earth system modelling (ESM). Pedotransfer functions (PTFs) used to predict soil hydraulic conductivity (K) take no account of land use. Here, we synthesize >800 measurements from around the globe from sites that measured near-saturated soil hydraulic conductivity, or infiltration, at the soil surface, on the same soil type at each location, but with differing land use, woodland (W), grassland (G) and cropland (C). We found that texture based PTFs predict K reasonably well for cropland giving unbiased results, but increasingly underestimate K in grassland and woodland. In native woodland and grassland differences in K can usually be accounted for by differences in bulk density. However, heavy grazing K responses can be much lower indicating compaction likely reduces connectivity. We show that the K response ratios (RR) between land uses vary with cropland (C/W = 0.45 [W/C = 2.2]) and grassland (G/W = 0.63 [W/G = 1.6]) having about half the K of woodland.
在过去300年里，全球土地利用变化导致牧场和农田增多，这在很大程度上是以牺牲林地为代价的。对于地球系统模型（ESM）而言，这种变化如何通过对水文循环的反馈来影响土壤水力功能尚不清楚。用于预测土壤水力传导率（K）的土壤传递函数（PTF）未考虑土地利用情况。在此，我们综合了全球800多个测量数据，这些数据来自于在每个地点对相同土壤类型、但土地利用情况不同（林地（W）、草地（G）和农田（C））的土壤表面近饱和土壤水力传导率或入渗进行测量的站点。我们发现，基于质地的PTF对农田K的预测相当准确，结果无偏差，但对草地和林地K的预测越来越低估。在原生林地和草地中，K的差异通常可由容重差异来解释。然而，重度放牧时K的响应可能低得多，这表明压实可能降低了连通性。我们表明，不同土地利用之间的K响应比（RR）各不相同，农田（C/W = 0.45 [W/C = 2.2]）和草地（G/W = 0.63 [W/G = 1.6]）的K约为林地的一半。
