Modern forestry vehicles and their impacts on soil physical properties
Modern forestry vehicles and their impacts on soil physical properties
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现代林业车辆及其对土壤物理性质的影响
DOI：
10.1016/j.still.2004.07.009
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发表时间：
2004
影响因子：
6.5
通讯作者：
S. Becker
中科院分区：
文献类型：
--
作者：
R. Horn;J. Vossbrink;S. Becker
“接近自然的林分”是德国科学研究部资助的“面向未来的森林管理”项目的核心内容之一。确定从纯云杉林到接近自然的混交林转变过程中机械化采伐程序的生态和经济后果是“南部黑森林研究合作”的一部分。分析了几种典型的森林采伐车辆的机械操作，以检查土壤剖面中的实际土壤应力和位移，揭示森林土壤的土壤物理性质的变化。采用应力状态传感器（SST）和位移传感器系统（DESS）测定了20和40 cm两个深度的土壤压实应力。在简短的9分钟的操作完成完整的收获和树干记录过程中观察到的时间分辨率为每秒20个读数。所有试验的最大垂直应力均超过200 kPa，某些车辆和采伐作业顺序在土壤深度20 cm处的最大垂直应力接近≥ 500 kPa。为了评估土壤应力对土壤结构的影响，通过测量预压应力来确定土壤内部强度。在田间试验点，森林土壤的预压应力值在20 cm深的土壤中为20 ~ 50 kPa，在40 cm深的土壤中为25 ~ 60 kPa，孔隙水压力为− 60 hPa。这些测量土壤应力及其自然承载力的数据证明，无论车辆类型和工作过程如何，持续的旋转都是不可能的。再次发生的顶部和底土压实，增加预压应力值在不同的土壤层，深车辙深度，垂直和水平的土壤位移与剪切应力，所有影响的森林土壤的机械强度。为了维持自然的“无轮”土壤区域的最小压实，建议使用较小的机器，具有较小的质量，完成森林采伐，以防止或至少保持目前最小压实的森林土壤。此外，如果需要更大的机器，必须建立永久轮和滑轨，以使其对未来的森林作业发挥最大作用。实现这些永久性道路的第一步需要与联邦州巴登-符滕贝格进行全面规划。最后用滑道打开的新指南（Landesforstverwaltung巴登-符滕贝格，2003年）建议使用20- 40 m宽的永久性滑道系统。
“Close-to-nature forest stands” are one central key in the project “Future oriented Forest Management” financially supported by the German Ministry for Science and Research (BMBF). The determination of ecological as well as economical consequences of mechanized harvesting procedures during the transformation from pure spruce stands to close-to-nature mixed forest stands is one part of the “Southern Black Forest research cooperation”. Mechanical operations of several typical forest harvesting vehicles were analysed to examine the actual soil stresses and displacements in soil profiles and to reveal the changes in soil physical properties of the forest soils. Soil compaction stresses were determined by Stress State Transducer (SST) and displacement transducer system (DTS) at two depths: 20 and 40cm. Complete harvesting and trunk logging processes accomplished during brief 9-min operations were observed at time resolutions of 20 readings per second. Maximum vertical stresses for all experiments always exceeded 200kPa and at soil depths of 20cm for some vehicles and sequences of harvesting operations approached ≥500kPa. To evaluate the impacts of soil stresses on soil structure, internal soil strengths were determined by measuring precompression stresses. Precompression stress values of forest soils at the field sites ranged from 20 to 50kPa at soil depths of 20cm depth and from 25 to 60kPa at soil depths of 40cm, at a pore water pressure of −60hPa. Data obtained for these measured soil stresses and their natural bearing capacities proved that sustainable wheeling is impossible, irrespective of the vehicle type and the working process. Re-occurring top and subsoil compaction, increases in precompression stress values in the various soil horizons, deep rut depths, vertical and horizontal soil displacements associated with shearing stresses, all affected the mechanical strengths of forest soils. In order to sustain naturally “unwheeled” soil areas with minimal compaction, it is recommended that smaller machines, having less mass, be used to complete forest harvesting in order to prevent or at least to maintain currently minimal-compacted forest soils. Additionally, if larger machines are required, permanent wheel and skid tracks must be established with the goal of their maximum usefulness for future forest operations. A first step towards accomplishing these permanent pathways requires comprehensive planning with the Federal State Baden-Württemberg. The new guideline for final opening with skid tracks (Landesforstverwaltung Baden-Württemberg, 2003) proposes a permanent skid track system with a width of 20–40m.