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森林资源状况和伐区作业条件的变化 ,使已往单一的机械化生产方式已不适应当前林业生产的需要。因此 ,必须结合实际 ,因地制宜 ,采用人机畜相结合的生产方式 ,才能降低成本 ,提高经济效益 ,有利于森林资源的培育和保护 相似文献
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A spatially explicit forest succession and disturbance model is used to delineate the extent and dispersion of oak decline under two fire regimes over a 150-year period. The objectives of this study are to delineate potential current and future oak decline areas using species composition and age structure data in combination with ecological land types, and to investigate how relatively frequent simulated fires and fire suppression affect the dynamics of oak decline. We parameterized LANDIS, a spatially explicit forest succession and disturbance model, for areas in the Boston Mountains of Arkansas, USA. Land type distribution and initial species/age class were parameterized into LANDIS using existing forest data. Tree species were parameterized as five functional groups including white oak (Quercus alba L., Quercus stellata Wangenh., Quercus muehlenbergii Engelm.), red oak (Qurecus rubra L., Quercus marilandica Muenchh., Quercus falcata Michx., Quercus coccinea Muenchh.), black oak (Quercus velutina Lam.), shortleaf pine (Pinus echinata Mill), and maple (Acer rubrum L., Acer saccharum Marsh.) groups. Two fire regimes were also parameterized: current fire regime with a fire return interval of 300 years and a historic fire regime with an overall average fire return interval of 50 years. The 150-year simulation suggests that white oak and shortleaf pine abundance would increase under the historic fire regime and that the red oak group abundance increases under the current fire regime. The black oak group also shows a strong increasing trend under the current fire regime, and only the maple group remains relatively unchanged under both scenarios. At present, 45% of the sites in the study area are classified as potential oak decline sites (sites where red and black oak are >70 years old). After 150 simulation years, 30% of the sites are classified as potential oak decline sites under the current fire regime whereas 20% of the sites are potential oak decline sites under the historic fire regime. This analysis delineates potential oak decline sites and establishes risk ratings for these areas. This is a further step toward precision management and planning. 相似文献
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洪崇恩 《绿色中国(A版)》2005,(7):38-41
浩然长江,从格拉丹冬雪域高原出发,跋涉6300公里,投入东海的怀抱。它向大海贡献了数千亿吨水量,还挟来数亿吨泥沙,在江口一带激荡汹涌、沉淀成陆,形成了数万平方公里的沙洲、土壤、沼泽、森林,为人类,也为鸟类、鱼类、两栖类、软体类、哺乳类等等动物,提供了栖息、觅食、繁衍的 相似文献
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A survey was conducted to determine richness of Vascular Endemic Plants of the Uluguru Mountains in Morogoro, Tanzania. Strict and near-endemic species were identified and their habits, habitats and altitudinal ranges were indicated. About 108 strict endemic plant species were identified in the Uluguru Mountains. Most of the endemic species are shrubs followed by herbs, trees and climbers, and are confined to the families Rubiaceae (38 species in 11 general), Orchidaceae (13 species in 7 general) and Balsaminaceae (11 species in 1 genus). The major habitat for endemic species is the montane rain forest on the windward side ranging between 1200 and 2450 m a.s.l. The major areas where the Uluguru endemics are concentrated are the forests of Bondwa/Lupanga followed by Lukwangule/Chenzema and then Bunduki and Mgeta. These areas are therefore the major hotspots for the endemism in the Uluguru Mountains. The information presented in this paper will contribute to the conservation and management of the biodiversity of the Uluguru Mountains. 相似文献
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Spice crops agroforestry systems in the East Usambara Mountains,Tanzania: growth analysis 总被引：1，自引：0，他引：1
A scarcity of cultivation land calls for more intensive and productive land use in the East Usambara Mountains in NE Tanzania.
Spice crops could generate cash in higher parts of the mountains, but the present cultivation methods are depleting the valuable
forest resources. The trial was established at the end of 2000 to find out how the two popular cash crops, cardamom (Elettaria cardamomum (L.) Maton.) and black pepper (Piper nigrum L.), normally grown under the natural forest, will produce in intensive agroforestry system with two multipurpose farm trees,
Grevillea robusta A.Cunn. and nitrogen fixing Gliricidia sepium Jacq. Results from 6 years showed that cardamom produced better with grevillea than in natural forest; 5.5 times more in
the fourth year than the average in the area. The Land Equivalent Ratios for black pepper and cardamom showed that pepper
intercropped with grevillea produced 3.9 times more than in monoculture whereas cardamom intercropped with grevillea and pepper
produced 2.3 times more than in monoculture. Gliricidia improved the nitrogen and organic matter content of the soil over
the levels found in natural forest. Soil acidity was, however, preventing the plants from using the available mineral nutrients
more effectively. 相似文献
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秦岭林区森林火灾发生的原因与对策 总被引：1，自引：0，他引：1
《陕西林业科技》2015,(3)
目前我国森林面积占国土面积的78.2%,森林资源蓄积量达946.5亿m3。为了保护好现有森林资源,做好森林火灾预防工作,本文针对秦岭林区森林防火工作的现状分析了秦岭林区森林火灾发生的原因并提出了相应的对策。 相似文献
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耿国彪 《绿色中国(综合版)》2012,(6):20-27
2012年是“十二五”规划承上启下的关键之年,也是党的十八大召开之年,社会各界对今年的全国两会给予了更多关注。在两会上,“民生”、“幸福”、“公平”和“环境”等词汇成了代表委员热议的话题。 相似文献
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文章对内蒙古大兴安岭林区水生植被的分布及组成进行了简要论述,初步划分了水生植被类型,指出了主要水生植被类型的生境特征,为今后保护水生植被提供基础资料。 相似文献
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《绿色中国(A版)》2020,(4):56-61
位于豫鄂交界大别山腹地的河南省新县,是远近闻名的大别山革命根据地首府所在地,也是刘邓大军千里跃进大别山的落脚地。革命战争年代,不足十万人的新县就牺牲了五万五千人,走出43位开国将军,在革命历史上留下了浓墨重彩的一笔。党的十八大以来,新县深入贯彻落实习近平总书记系列重要讲话精神,用实际行动践行"两山理论",坚持生态优先,遵循绿色发展,在这块红色的土地上,走出了一条绿色发展新路径。 相似文献
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文章通过对大兴安岭地区生态环境保护与建设的分析,指出了存在的主要问题,并提出了相应的对策。 相似文献
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“俊哥”有3个名字,一个名字叫刘俊,官职是原河北省林业科学研究院院长,职称是研究员;一个名字叫刘“忽悠”,是他自己给自己取的,并且在街头地摊上买了一本“货真价实”的“正版”“忽悠”证;一个名字叫“俊哥”,是河北省一些县、区的林农、果农给他取的,并且叫的非常亲切。 相似文献
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西藏色季拉山种子植物区系分析 总被引：2，自引：0，他引：2
色季拉山有种子植物1391种,隶属于491属,103科。其中裸子植物3科,9属,16种;被子植物100科,482属,1375种。色季拉山种子植物属的区系成分以温带成分为主,达324属,占总属数的73 4%,在植物区系的组成中居重要位置。种的区系成分以中国特有种占比例最大(573种,占总种数的41 49%),它们多是构成色季拉山优势植被类型的建群种和优势种的主要成分。类平均聚类分析表明,色季拉山种子植物区系与纬度偏北的太白山、中条山、太行山和太岳山植物区系比较接近,与纬度相近的庐山、木林子、神农架等植物区系差异较大。 相似文献
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绿化大青山是近几年包头市林业重点建设内容,就如何使大青山植被尽快恢复,根据多年实践和经验,提出大青山林业发展模式。 相似文献
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文章通过对内蒙古大兴安岭的现状分析,尤其对该地区的资源优势进行了大量的阐述,并指出了目前经营发展中存在的一些问题,着重阐述了内蒙古大兴安岭林区未来的转产方向,并对其发展前景做出了预测。 相似文献