热带次生林群落动态研究：回顾与展望

全球的热带次生林面积正快速增加,但人们对它们的生态、经济和社会效益的了解却十分有限,不同研究对次生林的理解和所使用的定义也不一样。在简要介绍热带次生林的现状之后,着重回顾热带次生林群落动态研究的主要成果,同时简述了现有研究中存在的问题和将来研究的重点课题及展望。     

中亚热带沟谷森林及经济植物资源科学考察研究

2007--2009年间,我们分别科学考察了中亚热带典型区系湖南省雪峰山脉和武陵山脉的沟谷森林,在剖析了沟谷地带的地形地貌,土壤和气候等自然特点的基础上,摸清了沟谷地带森林和经济植物资源,同时提出了沟谷森林自然生态环境的保护,通过这一科学考察,为人们认识和了解中亚热带沟谷森林植被与生境提供了科学依据,对中亚热带沟谷森林植被的保护和经济植物的开发利用具有重要意义。     

中亚热带单优群落的林层划分——以格氏栲群落为例

【目的】以格氏栲群落为例,研究中亚热带单优群落乔木层的林层划分,为进一步探讨林层特征及林层形成与发展动态提供先决条件。【方法】在福建三明莘口格氏栲自然保护区设置2块50 m×50 m格氏栲标准地,采用最大受光面法、剖面图法和基于有限正态混合模型的聚类法研究格氏栲群落的林层划分。【结果】2块标准地均为郁闭林分,且郁闭度均不低于0.95;1号标准地林分密度为424株·hm^-2、平均胸径为39.2 cm、平均树高为26.69 m、蓄积量为588.04 m3·hm^-2,2号标准地林分密度为542株·hm^-2、平均胸径为29.1 cm、平均树高为26.69 m、蓄积量为417.19 m3·hm^-2;3种林层划分方法均可给出林层数和各层临界高度,其中最大受光面法外业工作量少、使用简便,且分层结果具有明确的生物学意义;根据最大受光面法,格氏栲群落乔木层分为受光层和非受光层,2块标准地的临界高度分别为16.00和16.90 m,符合剖面图和基于有限正态混合模型的聚类分析结果;1号标准地受光层与非受光层林木株数比约为...     

和田河沿岸的中亚沙棘群落

和田河沿岸的中亚沙棘灌丛可分为沿岸阶地草甸中亚沙棘灌丛、盐碱滩地中亚沙棘灌丛、荒漠化中亚沙棘灌丛3种类型。     

农田防护林研究现状和展望

文章归纳总结了我国农田防护林发展历史、构建理论技术和防护效应,同时展望了农田防护林未来相关研究,以期为农田防护林发展和建设提供参考。     

不同功能防护林类型的判别技术研究

为了解决防护林类型选择技术问题,测定了洞庭湖水系内２７个主要防护林类型的生产力,林地土壤的渗透能力,水稳性指数,土壤最大蓄水能力,有效贮水能力及林分最大持水能力,并运用多级分辨等方法,对防护林类型的上述功能进行了判别分析,提出了１８个可供多种功能上选用的选择技术模型。选择技术模型回判结果,回判符合率多在７５％以上。     

川中丘陵区防护林群落多样性研究

本文对川中丘陵地区主要防护林群落的物种多样性进行研究,结果表明：①该流域共有维管束植物55科,82属,88种,其科、属、种数与四川省乃至全国比较,官司河流域植物区系具有组成简单的特点;②物种丰富度,物种多样性和均匀度指数都是人工林低于天然次生林,纯林林分低于混交林分;③土壤pH值、土壤有机质、土层厚度和人为干扰是影响防护林群落多样性发育的重要制约因子,其中土壤pH值是主导因子,制约着本区防护林群浇的空间分布格局;④林木高度、郁闭度和灌、草层盖度与物种丰富度、物种多样性指数和均匀度指数相关密切,对群落多样性发育的影响较大;而林木胸径与群落多样性指数相关不明显,对群落多样发育的影响不大。     

农田防护林垂直效益研究

通过网格式农田防护林内外风速、温度、湿度的观测对比分析，在１２．５ｍ树高的防护林网内，防护林在近地面低空对风的影响在１４倍树高以下，显著影响在８倍树高以下；对温度的影响在４倍树高以下；对湿度的电话号码 ２倍树高以下，显著影响在１倍树高以下?display structure     

崇武半岛防护林体系建设调查报告

从气候特征、风沙侵蚀、历史上毁林后果说明崇武半岛营造防护林的重要性,介绍崇武半岛防护林体系现状及其在降低风速、固定流沙、涵养水源及增加土壤有机质方面所发挥的巨大作用,总结出抓好林带(网)技术设计、选择良种、改进造林技术、注意抚育方式等营造防护林的主要经验以及存在的树种单调、经营粗放、人为活动频繁、乱砍滥伐等主要问题,最后就合理规划分期实施、巩固完善防护林体系、绿化大山、美化风景区等方面叙述对提高半岛防护林体系效益的设想。     

SITE CLASSIFICATION FOR PROTECTIVE FOREST AFFORESTATION ON THE COAST OF CHINA

Land for protective forest on the coast has special site conditions,and siteclassification is the scientific basis for seaboard afforestation.The site classification systemon the coast zone and islands of China may be classified into five levels-site region(sub-region),district,class,group,and type.The land division for afforestation is carried outby the principle of enviornmental heterogeneity among regions,sub-region and district onlarge scale,according to the difference of air temperature,moisture and type of coastgeomorphy.It may be classified into 7 regions,12 sub-regions and 55 districts.Themedium and small scaled division for site class,group and type,subdivided in a sitedistrict,are based on medium topography,topographic climate,micro-relief and soil conditions.     

塞罕坝自然保护区森林虫害分布特征的研究

通过对塞罕坝自然保护区森林害虫的调查,确定了虫害大规模爆发的时间,分析了害虫在林分中的主要空间分布规律以及害虫的种类,从而为当地的虫害管理提供了一定的技术基础。     

中亚热带常绿阔叶林不同演替阶段乔木层生物量特征

以中亚热带湖南省会同县处于演替早期的马尾松次生林、中期的马尾松阔叶树混交林和后期的常绿阔叶林分类型为研究对象,探讨了生态系统随不同演替阶段进行的乔木层生物量及空间分布特征。结果表明:乔木层生物量以常绿阔叶林最高,为292.51 t/hm~2,其次为针阔混交林,为206.87 t/hm~2,最小是马尾松林,为171.76 t/hm~2。乔木层生物量主要集中于树干,其占乔木层生物量比例由马尾松林向常绿阔叶林降低,而树根生物量所占比例由马尾松林向常绿阔叶林增加。马尾松林、针阔混交林和常绿阔叶林20 cm以上径级的生物量所占总生物量比例较大。     

防护林体系对噪声的影响

利用人工设置的噪声 ,在空旷、林带、片林进行了噪声强度测定 ,研究出噪声强度在空旷地、不同结构的林带、不同树种组成的林分中的变化情况 ,提出了防止环境噪声应采取的措施。     

对双鸭山林区森林分类经营的认识

本文对双鸭山林区森林的分类经营提出了几点认识,并做了具体分析。     

Soil nitrogen transformations varied with plant community under Nanchang urban forests in mid-subtropical zone of China

Soil N transformations using the polyvinyl chloride (PVC) closed-top tube in situ incubation method were studied in Nanchang urban forests of the mid-subtropical region of China in different months of 2007. Four plots of 20 m × 20 m were established in four different plant communities that represented typical successional stages of forest development including shrubs, coniferous forest, mixed forest and broad- leaved forest. Average concentrations of soil NH 4 + -N from January to December were not different among the four plant communities. The concentrations of soil NO 3 - -N and mineral N, and the annual rates of ammonification, nitrification and net N-mineralization under the early successional shrub community and coniferous forest were generally lower than that of the late successional mixed and broad-leaved forests (p<0.05). Similar differences among the plant communities were also shown in the relative nitrification index (NH 4 + -N/NO 3 - -N) and relative nitrification intensity (nitrification rate/net N-mineralization rate). The annual net N-mineralization rate was increased from younger to older plant communities, from 15.1 and 41.4 kg·ha -1 ·a -1 under the shrubs and coniferous forest communities to 98.0 and 112.9 kg·ha -1 ·a -1 under the mixed and broad-leaved forests, respectively. Moreover, the high annual nitrification rates (50-70 kg·ha -1 ·a -1 ) and its end product, NO 3 - -N (2.4-3.8 mg·kg -1 ), under older plant communities could increase the potential risk of N loss. Additionally, the temporal patterns of the different soil N variables mentioned above varied with different plant community due to the combined affects of natural biological processes associated withforest maturation and urbanization. Our results indicated that urban for- ests are moving towards a state of "N saturation" (extremely nitrification rate and NO 3 - -N content) as they mature.     

Disentangling the factors that contribute to variation in forest biomass increments in the mid-subtropical forests of China

Mid-subtropical forests are the main vegetation type of global terrestrial biomes, and are critical for maintaining the global carbon balance. However, estimates of forest biomass increment in mid-subtropical forests remain highly uncertain. It is critically important to determine the relative importance of different biotic and abiotic factors between plants and soil, particularly with respect to their influence on plant regrowth. Consequently,it is necessary to quantitatively characterize the dynamicspatiotemporal distribution of forest carbon sinks at a regional scale. This study used a large, long-term dataset in a boosted regression tree(BRT) model to determine the major components that quantitatively control forest biomass increments in a mid-subtropical forested region(Wuyishan National Nature Reserve, China). Long-term,stand-level data were used to derive the forest biomass increment, with the BRT model being applied to quantify the relative contributions of various biotic and abiotic variables to forest biomass increment. Our data show that total biomass(t) increased from 4.62 9 106 to 5.30 9 106 t between 1988 and 2010, and that the mean biomass increased from 80.19 ± 0.39 t ha-1(mean ± standard error) to 94.33 ± 0.41 t ha-1in the study region. The major factors that controlled biomass(in decreasing order of importance) were the stand, topography, and soil. Stand density was initially the most important stand factor, while elevation was the most important topographic factor. Soil factors were important for forest biomass increment but have a much weaker influence compared to the other two controlling factors. These results provide baseline information about the practical utility of spatial interpolationmethods for mapping forest biomass increments at regional scales.     

韶山风景名胜区植被类型划分

依据韶山风景名胜区丘陵植被小区所辖地理区域内调查的13个标准样地;采用样地植物物种重要值进行样地欧氏距离计算的等级聚合分类法和中国植被的分类单位系统,对韶山风景名胜区原生森林植被类型进行划分,共划分出4个森林植被类型。     

关于森工林区小城镇建设的思考

笔者作为在森工林区长期生活、工作的建设工作者,根据自己掌握的情况,对森工林区的小城镇建设进行了一番思考和探索;详细分析了森工林区小城镇建设的现状及急需解决的问题;并从政治、经济、商业、交通、地域等多方面论述了发展森工林区小城镇建设的必要性;同时对如何才能加快森工林区小城建设步伐提出了改革措施及合理化建议。