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中国热带次生林分布、类型与面积研究 总被引：2，自引：0，他引：2
热带林的保护问题已受到世界各国的高度重视,由于占世界热带林面积约三分之一的热带次生林,其经济和生态效益通常较差,处于相对被忽视的状态,因此也往往被进一步破坏。将次生林经营纳入可持续经营的轨道,是实现热带林可持续经营目标的重要战略。通过对中国热带森林研究、经营和统计资料的分析,结合本项目实施过程的实地调研取得的结果,文章对中国热带地区次生林分布、面积和类型作了阐述。热带森林主要分布在海南、广东、广西、云南、台湾,以及福建和西藏的部分地区,包括124个县市的全部和50个县市的部分地区。据可认可的资料统计,中国热带林地面积（不含台湾省）约1125．66万hm^2。其中有林地面积1074．49万hm^2,次生林面积544万hm^2。次生林占热带地区林地面积的48．33％,占有林地总面积的50．63％。中国热带林地和次生林的实际数字估计要比这一数值大6％以上,因为中国这几年高度重视林业建设,森林植被特别是热带森林植被恢复得很快,林地和次生林一直在不断增加。热带森林类型主要有：热带雨林（包括湿润雨林、山地雨林）;热带季雨林（包括半常绿季雨林、落叶季雨林、石灰岩季雨林）;南海珊瑚岛植被;海岸红树林等。从森林经理的角度,中国热带次生林的类型可分为：（1）次生阔叶林,包括次生常绿阔叶雨林、次生季雨林和次生季风常绿阔叶林;（2）次生灌木林;（3）次生针叶林;（4）次生红树林及次生珊瑚岛林等四大类型。 相似文献
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摘要 在国际热带木材组织（ITTO）的资助下,广东省林业科学研究院在广东新会和海南通什开展了“旨在提高生态和经济效益的热带地区次生林经营研究与示范”。其目的是通过在干扰破坏较严重的次生林中引入具有较好生态和经济效益的优良物种,使林分物种增加,林区居民能从经营中取得非木质产品的经济收益,达到保护和促进次生林的生长发育的目的,实现森林可持续经营的目标。本文广东新会热带次生林经营研究与示范区活动中,通过91个引入物种的试验研究,其中区域缺失和退化的乡土树种68中,占75%;外来树种13种,占14%;非木质产品物种10种,占11%。总结了低质低效次生林经营中物种选择的原则、方法和经营效果。 相似文献
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在国际热带木材组织（ITTO）的资助下,广东省林业科学研究院在广东新会和海南通什开展了“旨在提高生态和经济效益的热带地区次生林经营研究与示范”活动。其目的是通过在干扰破坏较严重的次生林中引入具有较好生态和经济效益的优良物种,使林分物种增加,林区居民能从经营中取得非木质产品的经济收益,达到保护和促进次生林的生长发育的目的,实现森林可持续经营的目标。在广东新会热带次生林经营研究与示范区活动中,选择101个引入物种进行试验研究,其中区域缺失和退化的乡土树种68种,占67．3％;外来树种13种,占12．9％;非木质产品物种20种,占19．8％。总结了低质低效次生林经营中物种选择的原则、方法和经营效果。 相似文献
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为更好地开展热带次生林经营,在国际热带木材组织“旨在提高经济和生态效益的热带地区次生林经营研究与示范”项目（ITTO PD294／04）的资助下,对较为典型的中国热带次生林——广东古兜山林区开展了森林资源与社会经济状况的相关调查,其结果认为：中国热带林区的热带森林除自然保护区外,几乎都以低产低质的次生林状况存在,这类林分质量普遍较差,很少开展经营活动,因此缺乏经济和生态效益。林区居民主要依靠政府的生态公益林补偿、砍伐林木、出租林地供商品林经营以及农耕等获得收入,生活仍然处于比较贫困的状态,人均年收入仅3780元（约合556美元）。林农普遍的愿望是将次生林地改种以桉树为代表的速生丰产商品林经营,以获得较高的经营效益,次生林的保护仍然面临巨大的压力： 相似文献
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据 1998年原始林副总体清查成果 ,论述了原始林副总体森林资源现状 ,并通过与前次清查成果对比 ,分析了副总体在这五年内森林资源变化情况 ,森林经营和森林采伐效果等。评价了森林经营质量和经营中存在的问题 ,提出了森林经营管理的具体建议。 相似文献
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论天然林保护工程的科技支撑 总被引：1，自引：0，他引：1
何谓天然林，天然林是指依靠自然力形成的森林，包括原始林和天然次生林。原始森林是尚未经人类经营活动或人为破坏的森林，天然次生林是原始林经过采伐或多次破坏后自然恢复起来的森林。［１］天然林保护工程是我国为改善人类生态和社会经济发展的生态环境及物种多样性所... 相似文献
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天然次生林经营技术与措施 总被引：3，自引：0，他引：3
“次生林”一词是随着人们对森林研究的不断深入和森林经营工作的不断加强而出现的。次生林是森林的一大类型,是相对于原始林而言的。它是指原始林由于采伐、开垦、火灾和其他人为因素、自然灾害而遭受破坏后,经自然恢复而成的次生群落。有些人工林在采伐后又生长起原栽培树种的萌生林木与天然发生的其他树种混生形成的林分,亦称之为次生林。本文所指天然次生林则是前者。天然次生林中确实有些类型是劣质低产的,它们与原始林相比,树种的经济价值较低,木材产量较少,但也有相当一部分是优质高产的。按照比较通用的分类方法,根据林分的自然类型… 相似文献
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Juan Carlos lvarez-Ypiz Angelina Martínez-Yrízar Alberto Búrquez Cynthia Lindquist 《Forest Ecology and Management》2008,256(3):355
The objective of this study was to compare the vegetation structure and soil properties among old-growth tropical dry forests representing three categories of grazing intensity by cattle (light, moderate and heavy grazing) and a category of 20–30-yr-old secondary forest experiencing occasional grazing in a locality in northwestern Mexico. Within each forest type, three 0.1 ha plots located in different grazing ranges (“potreros”) were used as replicates. All woody plants (stem ≥ 2.0 cm diameter at 1.30 m height, DBH) were identified and measured in each plot. Mean basal area and above-ground biomass (AGB) were significantly higher in the moderately grazed old-growth forest. Species density was significantly lower in the secondary forest, where a leguminous tree species was dominant. Accumulation of AGB after 20–30 yr of secondary forest recovery accounted for 43% of the old-growth forest AGB. Soil properties varied among forest categories but did not follow a consistent pattern: mean total N and organic matter content were highest in the old-growth forest with moderate grazing; cation exchange capacity (CEC) was similar among the three old-growth forests categories, but it was significantly lower in the secondary forest compared to the old-growth forest with low grazing. Canonical Correspondence Analysis showed that CEC was highly correlated with the actual species distribution in the study area, especially with Acacia cochliacantha the dominant species of the secondary forest category. Resprouting capacity of the persisting species in the old-growth forests experiencing chronic disturbance could have contributed to the maintenance of some of the structural characteristics of a mature forest. Tropical secondary forests seem to accumulate AGB relatively fast, reflecting their potential for carbon storage and provision for other ecosystem services; therefore, they deserve urgent protection measures. 相似文献
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按照“激励相容”原理启动热带次生林和退化林地的可持续经营 总被引：2，自引：2，他引：2
中国热带天然次生林和退化林地约有1000万hm2,约占热带国土总面积的1/3。在这里,涉及森林资源可持续经营和经济社会可持续发展的基本课题尚未解决。文中建议利用“激励相容”的原理,针对中国的3种次生林和退化林地大类型,选择典型地区,按照尽可能接近当地社区及居民的原则,建立一个由分散化、微型化和多样化示范的小区组成的示范体系,高效率地推进热带次生林和退化林地的可持续经营,增强热带经济社会发展的弱可持续性并进一步向强可持续性转化。 相似文献
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关于中国东北地区森林经营的对话 总被引：2，自引：1，他引：1
中国东北地区有3700多万hm2森林资源, 大部分为已严重退化的天然次生林。如何经营这些森林, 是不予管理、任其退化, 直至形成杂灌丛; 还是"砍次留好", 促进更新, 逐步引向永久性森林?哈尔滨市林业局在山河、转山和丹青河3个直属林场, 开展了以均衡发挥生态效益和经济效益为目地的经营实践, 仅10余年时间3个林场就已获得了低投入、高产出的良好效果, 走上了资源与经济良性循环的轨道。2009年9月, 哈市林业局在中国林科院专家支持下, 邀请德国森林经营专家Heinrich Spiecker教授和法国农业部高级顾问Dominique Danguy des Deserts先生考察了经营现场, 并深入探讨了这些科学实验及其理论价值。 相似文献
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森林系统的存在与演化 总被引：3，自引：3，他引：0
第四纪的热带、亚热带、温带、寒带森林,可划分为"单层同龄林分"类型和"复层异龄林分"类型,它们都遵循着由"初始林分"走入"过熟林分"的"优胜劣汰"规则。森林产生的"死亡量"必定小于"净生长量",这种非线性的"物质运动"与热力学过程的"熵"联系起来,则能更深刻地诠释由孢子植物进化为裸子植物,进而进化为被子植物的多样性树种所组成森林的"森林耗散结构"特性。现代的森林包涵着两类林分:一类是由单一树种组成的"单层同龄林分",是不通过"树种演替"就能形成"初始林分"的林分,因而其具有简单的"内部结构"和"内部时间";另一类是由多"种群"组成的"复层异龄林分",其必需通过"树种演替"才能形成"初始林分",因而它具有复杂的"内部结构"和"内部时间"。对云南的森林,已量测到亚热带阔叶林的"过熟林分"。却缺少"先锋种群"演变为"初始林分"的先前事件,因此不可能描述出其"复层异龄林分"的先前概率。由对云南森林的分析得出,两类"林分"虽都遵循"优胜劣汰"规则,但却只能导算出"单层同龄林分"的"株数递减率和蓄积量递增率"的过程。 相似文献
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《Forest Policy and Economics》2004,6(1):63-70
Policy-makers in most countries now recognise the need to conserve biodiversity, forest productivity and the prosperity of forest dependent communities in the long-term. There is wide recognition of the importance of forested watersheds to hydrological regimes and water quality and the significant cultural, social and aesthetic values of forests. Policies are now directed at achieving sustainable forest management (SFM). Criteria and indicators (C&I) define SFM but obtaining agreement on what SFM is has proven to be a difficult task internationally and nationally. International activities including the work of the International Tropical Timber Organisation (ITTO), the European Union (EU) and the Montreal Process (MP) for temperate and boreal forests outside Europe, have, over the past decade refined C&I for SFM to the point now that there is substantial agreement between them. This paper reviews progress towards defining SFM and shows through a synthesis of the ITTO, EU and MP C&I the emergent consistency in defining SFM. The implication is that there are now sufficiently specific and agreed principles, C&I to guide policy-makers towards SFM. While much work remains to be done to operationalise the C&I, the gap between these agreed criteria and current practice for forest management is so wide that progress can be made within the frameworks while refinement continues. 相似文献
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We investigated the population age structure and spatial patterning of a common understory perennial, Trillium erectum var. album, in primary and post-logging secondary (industrially logged in the early 1900s) cove forests of the southern Appalachian Mountains. Within each of 8 T. erectum populations (4 in primary forest and 4 in secondary forest), we mapped the locations of all T. erectum plants in a 10 m × 10 m plot located within the center of each population. We recorded the height and life stage of each plant and excavated a randomly selected subset for age determination. Trillium erectum populations in primary forests displayed a somewhat stronger and more consistent spatial structure than those found in secondary forests. However, aside from being on-average younger due to a higher concentration of juveniles, age structures of secondary forest populations were similar to those of primary forests and both forest types had similar maximum plant ages. Our results, when considered with the life history of the species, suggest that logging did not eliminate T. erectum from secondary forests. Rather, residual plants and patches of plants that survived logging provided the propagules needed to expand and reestablish populations following logging. This relatively rapid recovery stands in stark contrast to the slow recovery observed by others in post-agricultural secondary forest. When considered in the context of other studies of post-disturbance recovery in secondary forests, our results suggest that the full history of a site must be carefully considered when examining the impacts of disturbance on forest perennial herbs. 相似文献