Institute of Social Ecology Vienna (SEC), Alpen-Adria Universitaet Klagenfurt, Wien, Graz, Schottenfeldgasse 29, Vienna, 1070, Austria.
LSCE-IPSL CEA-CNRS-UVSQ, Orme des Merisiers, Gif-sur-Yvette, F-91191, France.
Glob Chang Biol. 2017 Feb;23(2):512-533. doi: 10.1111/gcb.13443. Epub 2016 Sep 22.
In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human-induced changes in terrestrial ecosystems that do not result in land-cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one-tenth of the ice-free land surface is under intense human management, half under medium and one-fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling.
在气候变化、生物多样性丧失和粮食安全等严峻的全球可持续性挑战面前，增进我们对地球系统复杂动态的理解至关重要。然而，与土地管理相关的大量知识空白仍然存在，特别是那些不会导致土地覆盖转变的人为改变陆地生态系统的变化。在这里，我们回顾了十种常见土地管理活动对其生物地球化学和生物物理影响、过程理解水平和数据可用性的当前知识状况。我们的综述表明，大约有十分之一的无冰地表受到强烈的人为管理，一半受到中等程度的管理，五分之一受到广泛的管理。基于我们的综述，我们将这十种管理活动分为三组：（i）有数据可用且有良好知识库的管理活动（耕地收获和灌溉）；（ii）有足够的生物地球化学和生物物理效应知识但缺乏稳健的全球数据集的管理活动（森林收获、树种选择、放牧和刈割收获、氮施肥）；（iii）土地管理实践数据严重缺失且过程理解水平不令人满意的管理活动（作物品种选择、人工湿地排水、耕作和火灾管理以及作物残茬管理，是作物收获的一个要素）。尽管我们确定了多个阻碍进展的因素，但我们得出的结论是，目前的过程理解和数据可用性足以推进将管理纳入地球系统或动态植被模型等工作，以便对其在地球系统中的作用进行系统评估。本综述有助于在包括土地系统研究、生态研究和地球系统建模在内的多个学科中对研究工作进行战略性优先排序。
