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Using a constant-head permeameter we found an abrupt natural decrease in saturated hydraulic conductivity (Ks) within the upper 1.0-m soil profile of an Orthoxic Tropudult at the Bukit Tarek Experimental Catchments research area in tropical, Peninsular Malaysia. The depth at which low Ks could cause a perched water table in response to high-intensity rainfall, however, was too great to generate saturation overland flow on planar hillslopes in the study area. The effects of logging activity on Ks at five subsurface depths (0.1, 0.25, 0.5, 0.75, and 1.0 m) on the non-roaded portion of the harvest area were examined at the three following sites, which differed in the degree of disturbance and recovery since timber harvesting: (1) selective logging conducted in the 1960s; (2) mechanized selective tree removal conducted 4 years ago; and (3) high-impact clear-cutting just prior to measurement. This recent logging greatly disturbed the soil surface (via compaction, topsoil/subsoil mixing, burning) and produced comparatively high variability in near-surface Ks. Changes in Ks at or below 0.25-m, however, were not detected with certainty at any sites. In terms of hillslope hydrologic response, the connectivity of zones of low Ks in the harvest area with dense networks of skid trails and terraces was identified as one of the most important consequences of timber harvesting, although this phenomenon was not quantified. We estimate the recovery time for near-surface Ks on the non-roaded hillslope to be less than 40 years. 相似文献
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《Journal Of Agricultural & Food Information》2013,14(3):19-23
ABSTRACT The Forestry Library of the University of Minnesota produces four bibliographic databases that are mounted on a Gopher server and are available to researchers over the Internet. The four databases are Social Sciences in Forestry; Urban Forestry; Tropical Forest Conservation and Development; and Trail Planning, Construction, and Maintenance. The four databases cover subjects which, because of their interdisciplinary nature and pattern of publication, tend to receive poor coverage in the standard forestry databases. These databases reflect the collections of the University of Minnesota. 相似文献
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为进一步促进登山健身步道建设向更安全、舒适、健体和保护生态的方向拓展,探讨在江浙沪地区丘陵型登山健身步道建设的适宜性,选取5座江浙沪丘陵的20条登山健身步道进行调查,从步道布局与形态、界面特征、景观特征三方面分析现状特征;结合登山健身者行为需求问卷调查,从安全性、功效性、舒适性、环境友好度四个维度,甄选出14个评价指标;运用AHP层次分析法构建适宜性评价体系,运用于丘陵型登山健身步道建设适宜性评价,得出结论:江浙沪丘陵型登山健身步道,应以建设材料的生态与乡土性、沿线景观多样性与美感度、与其他步道的连接度、生态保护措施完善度为重点建设指标,从生态保护、健身功效、人性关怀、人身安全四方面提升其适宜性。本研究对同类和类似步道的规划设计具有参考价值。 相似文献
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2004年,在云南勐腊植胶区勐腊农场进行橡胶树新品种‘热研8-79’区域性种植试验,2011年正式进入割胶。统计资料表明:该品种幼树期生长较快,7年生胶树年平均茎围生长量达8.17 cm,分别为对照传统种植品种GT1的106.94%和PR107的112.69%,达到开割标准的胶树达73.56%,比对照品种提前一年投产,缩短橡胶树的非生产期,降低在非生产期的管理费用投入;开割第4年平均单株干胶产量达3.91 kg/株,为对照品种GT1的124.52%、PR107的174.55%,充分表现出该品种在勐腊植胶区域具有速生、高产、早熟的品种特点。 相似文献
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收集广东、海南、广西及福建地区 10 个降香黄檀（Dalbergia odorifera）种子并培育，比较分 析不同家系的早期生长表现。结果表明：不同家系间树高、地径、保存率存在极显著差异；综合生长指 标以肇庆广宁中学、广州华农林学院，海南乐东抱由林业局和海南乐东抱由苗圃场共4 个家系表现最好， 可作为降香黄檀采种育苗或无性繁殖的材料加以重点研究；树高与海拔存在显著正相关，说明一定范围 内较高海拔有利于树高的生长；年均降雨量与地径、保存率均存在显著正相关，说明一定范围内年均降 雨量越大，越有利于促进降香黄檀径的增长及提高苗木保存率。 相似文献
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橡胶树新品种热垦628 于2004～2014年在云南省勐腊植胶区勐腊农场进行区域性种植试验,2011年正式割胶。统计结果表明：该品种生长较快,种植10 a平均茎围生长量68.89 cm,分别为传统种植对照品种GT1和PR107的115.70%和113.60%,种植后7 a达到开割标准的胶树为53.9%,比对照品种提前1 a投产,缩短橡胶树的非生产期,降低非生产期管理费用投入;开割第4年平均单株干胶产量达4.19 kg/株,分别为对照品种GT1 和PR107的133.44%和187.05%,平均产量1 183.5 kg/hm2。该品种在勐腊植胶区表现出速生、高产、早熟等特性,是较好的胶木兼优品种,为对该品种的适应性和特性作出全面评价,应考虑在本地区进一步扩大试种并继续对其进行系统鉴定。 相似文献