林木分布格局多样性测度方法: 以阔叶红松林为例

林木分布格局是森林结构的重要组成部分, 直接影响森林生态系统的健康与稳定, 维持森林结构多样性被认为是保护生物多样性的最佳途径。本研究探讨了林木分布格局多样性的测度方法, 以期为揭示森林结构多样性提供理论依据。格局多样性研究的关键在于选择合适的生物多样性测度方法和具有分布属性的格局指数。本研究通过统计角尺度分布频率和Voronoi多边形边数分布频率, 运用Simpson指数分别计算角尺度多样性和Voronoi多边形边数分布多样性, 作为表达林木分布格局多样性指数的方法, 并以我国东北吉林蛟河的3个100 m × 100 m的阔叶红松(Pinus koreansis)林长期定位监测标准地为例, 分析了林木分布格局的多样性。结果表明: 无论是角尺度分布还是Voronoi多边形的边数分布都接近正态分布, 角尺度分布中随机分布林木的频数最多, 占55%以上; Voronoi多边形的类型多达10个以上, 50%以上的林木有5-6株最近相邻木。利用Simpson指数衡量林木格局多样性, 角尺度分布与Voronoi多边形的边数分布都显示出聚集分布的林分比随机分布林分的格局多样性高。研究还发现, 两种格局判定方法得出的Simpson指数值有所不同, 角尺度分布的多样性数值明显低于Voronoi多边形的边数分布的多样性数值, 主要原因是二者的等级数量不同。可见, 林木分布格局多样性研究应选择具有分布属性的格局指数, 但由于各指数反映的角度不同, 所以在分析比较不同林分格局多样性时应采用相同的分析方法。     

滇西北藏区自然圣境与传统文化驱动下的生物多样性保护

本研究旨在将滇西北藏区传统生态文化应用于社区生物多样性保护之中, 以推动社区参与式生物多样性保护和森林生态系统的修复。应用民族植物学和民族生态学的方法, 调查了位于白马雪山国家级自然保护区及周边地区的3个藏族村寨(巴珠、柯功、追达)的自然圣境与生物多样性分布状况及其生态服务功能等, 应用SWOT分析法和社区参与式保护途径, 开展了生物多样性保护示范活动。本研究结果表明, 社区保护生物多样性的主要驱动力来源于民族传统文化, 社区生计依赖于生物多样性, 保护自然圣境是社区水平保护生物与文化多样性及社区发展的重要途径。藏族自然圣境是基于传统信仰文化并经过长期实践建立和发展起来的有利于生物多样性保护的社区保护形式, 藏民社区长期遵从和实践自然圣境对生物多样性保护做出了重要贡献。     

我国林业基础研究刍议

自然科学基础研究是整个科学技术研究的重要组成部分,是应用研究及高技术研究的奠基石。作为自然科学中的一个组成部分,林业科学亦不例外,其应用研究和开发研究的成功和发展在很大程度上依赖于林业基础研究的深化,即对森林自然现象的认识和了解。林业基础研究在宏观方面,主要是揭示森林发生、发育的客观规律及原理,包括森林生物间相互依存、相互制约的机理研究,森林生物多样性的研究,森林生态系统的研究,森林群体遗传规律的研究,林业基本科学数据的收集、整理及分类研究,森林病虫害发生规律的研究,森林与外界环境的相互关系研究,森林资源动态变化规律以及森林经营活动中的自然规律研究。     

中国森林生物多样性监测网络(CForBio):二十年进展与展望

大型森林动态监测样地是研究群落尺度森林动态变化的最优途径之一。中国森林生物多样性监测网络(CForBio)始建于2004年,是全球森林生物多样性监测网络(ForestGEO)最活跃的组成部分之一。CForBio森林动态监测样地一般为20ha,同时建立3–5个1–3ha辅助样地,以统一技术规范对胸径≥1 cm的木本植物进行定位监测,旨在长期监测中国主要森林类型的生物多样性格局与动态,研究其形成和维持机制。本文简要介绍了CForBio的概况、主样地建设、数据共享、能力建设、基于长期监测数据的主要科学发现以及科学支撑和服务,夯实CForBio监测与研究、拓展专题网络并加强能力建设,可为以监测数据为基础的森林生物多样性保护管理决策以及国际履约提供科学依据。     

中国特有野生酿酒葡萄的群体基因组学分析

葡萄是中国的重要经济植物,酿酒葡萄更是葡萄产业的重要部分。本研究通过34份酿酒葡萄基因组重测序数据,研究中国三种特有野生酿酒葡萄山葡萄(Vitis amurensis)、刺葡萄(Vitis davidii)和毛葡萄(Vitis heyneana)的群体间遗传结构、遗传多样性与群体历史变化,通过群体遗传学手段筛选选择信号,挖掘中国野生酿酒葡萄特有的重要种质基因。群体结构显示群体间聚成四个分支。与中国主要栽培酿酒葡萄相比,三个野生酿酒葡萄群体多样性较低,且均受东亚大陆末次冰期的影响,导致群体有效数量较低,相关野生种质资源需要得到进一步的保护和收集。通过对中国野生酿酒葡萄共同受选择区域进行定位,本研究共鉴定到272个中国野生酿酒葡萄受选择的基因,这些基因富集到葡萄有性生殖、花粉形成、淀粉和蔗糖代谢,以及自噬体等功能或通路上,研究结果能为栽培酿酒葡萄今后的杂交育种、抗病和酿酒风味等方面提供重要的育种依据。这些基因可能与中国野生葡萄长期受本土环境影响而形成的独特生长发育过程有关。本研究可为中国原产野生酿酒葡萄的保护及育种应用提供重要理论依据。     

农作物生物育种产业化情况及发展趋势

全球经济发展、人口增长给粮食生产带来了严峻挑战,而农作物种业是国家战略性、基础性核心产业,是促进农业长期稳定发展、保障国家粮食安全的根本。本文从农作物生物育种技术出发,对单倍体育种、杂交育种、诱变育种、多倍体育种和细胞工程育种等常见生物育种技术进行了介绍,以及对国内外农作物生物育种产业化情况进行了深入分析,并展望了未来种业发展趋势。     

木本油料植物麻疯树的研究进展

近来,麻疯树(Jatropha curcas L.)因可以作为生物柴油的原料而受到广泛关注。虽然麻疯树具有含油量高且可在边际土地种植的优势,但同时存在理想品种缺乏、种植面积限制、基础研究薄弱等方面的问题。为了使常规育种和生物技术改良工作者更好地了解麻疯树的研究进展,确定日后麻疯树育种和遗传改良的方向,综述了麻疯树种质资源与遗传多样性分析、生理及对环境适应性、组学研究、油脂合成功能基因研究、育种等方面国内外的最新进展。     

分子标记及其在植物遗传育种中的应用

遗传标记可以说是生物群体中可识别的遗传多态性的一种表现形式。随着遗传研究特别是遗传作图的不断深入,遗传标记已从传统的以等位基因的表型识别为基础的形态标记、以染色体的结构和数目为特征的细胞学标记,及具有组织、发育及物种特异性的同工酶标记,拓展到目前已广泛应用的以ＤＮＡ多态性为基础的分子标记技术。现代分子标记技术的出现和发展为植物遗传育种研究的许多领域注入了新的活力。本文着重就目前植物遗传育种中所应用的一些主要分子标记技术及其应用作一概述。１　常用的分子标记技术自８０年代初有人提出用ＲＦＬＰ作为遗传…     

中国森林种子植物区系的特征

本文主要根据中国种子植物区系研究的最新资料,简要介绍中国现代森林种子植物区系的多样性、地理成分、区系性质及地区差异等特征,供森林研究和中国生物多样性研究参考。     

中国森林冠层生物多样性监测

林冠作为森林与外界环境相互作用最直接和最活跃的关键生态界面,承载了森林生物多样性的主体,在生物多样性的形成与维持以及生态系统功能过程中发挥着重要的作用,被称为地球的"第八大洲"。同时,林冠对气候变化和人为干扰高度敏感,在人类活动和全球气候变化加剧的背景下,森林生态系统正面临着严重的威胁,首当其冲的就是森林冠层。气候变化下的林冠生物多样性保护与可持续利用已成为现代生态学研究的热点问题,受到森林生态学、气候学、环境科学等研究领域的学者越来越多的关注。据此,中国生物多样性监测与研究网络以网络内拥有森林冠层塔吊的生物多样性监测样地为平台,建立了林冠生物多样性监测专项网。该专项网将参照国际标准,统一监测指标,规范监测标准,通过大尺度地带性森林冠层内植物(包括附生种子植物和附生孢子植物)多样性、动物多样性、微生物多样性及其动态变化的长期监测,结合林冠小气候环境特征监测,建立林冠小环境特征、植物多样性、节肢动物多样性和微生物多样性等4个动态更新的数据库,以阐明我国典型森林林冠生物多样性变化的规律,揭示其对森林生态系统功能过程的影响和对全球变化的响应。     

Demographic costs and benefits of natural regeneration during tropical forest restoration

For tropical forest restoration to result in long‐term biodiversity gains, native trees must establish self‐sustaining populations in degraded sites. While many have asked how seedling recruitment varies between restoration treatments, the long‐term fate of these recruits remains unknown. We address this research gap by tracking natural recruits of 27 species during the first 7 years of a tropical forest restoration experiment that included both planted and naturally regenerating plots. We used an individual‐based model to estimate the probability that a seedling achieves reproductive maturity after several years of growth and survival. We found an advantage for recruits in naturally regenerating plots, with up to 40% increased probability of reproduction in this treatment, relative to planted plots. The demographic advantage of natural regeneration was highest for mid‐successional species, with relatively minor differences between treatments for early‐successional species. Our research demonstrates the consequences of restoration decision making across the life cycle of tropical tree species.     

Accelerating the domestication of forest trees in a changing world

In light of impending water and arable land shortages, population growth and climate change, it is more important than ever to examine how forest tree domestication can be accelerated to sustainably meet future demands for wood, biomass, paper, fuel and biomaterials. Because of long breeding cycles, tree domestication cannot be rapidly achieved through traditional genetic improvement methods alone. Integrating modern genetic and genomic techniques with conventional breeding will expedite tree domestication. Breeders will only embrace these technologies if they are cost-effective and readily accessible, and forest landowners will only adopt end-products that meet with regulatory approval and public acceptance. All parties involved must work together to achieve these objectives for the benefit of society.     

Can we rely on forest reserves for primate conservation?

Tropical forests contain much of the world's biodiversity, yet their rate of decline is increasing. The strategy most frequently used to protect this biodiversity is to make parks and reserves. While there is a great deal of research on the effectiveness of parks for protecting biodiversity, there is little research on how well extractive reserves conserve biodiversity. Here, we evaluate the effectiveness of four forest reserves in western Uganda at maintaining populations of primates and compare census data from the reserves to data from the neighbouring well‐protected Kibale National Park. The relative abundance of the five most common primates in the park was approximately four times that of the forest reserves. In the forest reserves, evidence of new human encroachment was seen every 500 m, while in the park it was seen every 100,000 m. Two recommendations emerge from our research: (i) for forest reserves, such as those studied here, to have conservation value for primates, extraction must be reduced and (ii) until the long‐term viability of the populations in forest reserves can be ascertained, they should not be considered in estimates of the sizes of endangered species protected ranges.     

Native tree regeneration in native tree plantations: understanding the contribution of Araucaria angustifolia to biodiversity conservation in the threatened Atlantic Forest in Argentina

Deforestation is a global process that has strongly affected the Atlantic Forest in South America, which has been recognised as a threatened biodiversity hotspot. An important proportion of deforested areas were converted to forest plantations. Araucaria angustifolia is a native tree to the Atlantic Forest, which has been largely exploited for wood production and is currently cultivated in commercial plantations. An important question is to what extent such native tree plantations can be managed to reduce biodiversity loss in a highly diverse and vulnerable forest region . We evaluated the effect of stand age, stand basal area, as a measure of stand density, and time since last logging on the density and richness of native tree regeneration in planted araucaria stands that were successively logged over 60 years, as well as the differences between successional groups in the response of plant density to stand variables. We also compared native tree species richness in planted araucaria stands to neighbouring native forest. Species richness was 71 in the planted stands (27 ha sampled) and 82 in native forest (18 ha sampled) which approximate the range of variation in species richness found in the native forests of the study area. The total abundance and species richness of native trees increased with stand age and time since last logging, but ecological groups differed in their response to such variables. Early secondary trees increased in abundance with stand age 3–8 times faster than climax or late secondary trees. Thus, the change in species composition is expected to continue for a long term. The difference in species richness between native forest and planted stands might be mainly explained by the difference in plant density. Therefore, species richness in plantations can contribute to local native tree diversity if practices that increase native tree density are implemented.     

Fire effects and ecological recovery pathways of tropical montane cloud forests along a time chronosequence

Tropical montane cloud forests (TMCFs) harbour high levels of biodiversity and large carbon stocks. Their location at high elevations make them especially sensitive to climate change, because a warming climate is enhancing upslope species migration, but human disturbance (especially fire) may in many cases be pushing the treeline downslope. TMCFs are increasingly being affected by fire, and the long‐term effects of fire are still unknown. Here, we present a 28‐year chronosequence to assess the effects of fire and recovery pathways of burned TMCFs, with a detailed analysis of carbon stocks, forest structure and diversity. We assessed rates of change of carbon (C) stock pools, forest structure and tree‐size distribution pathways and tested several hypotheses regarding metabolic scaling theory (MST), C recovery and biodiversity. We found four different C stock recovery pathways depending on the selected C pool and time since last fire, with a recovery of total C stocks but not of aboveground C stocks. In terms of forest structure, there was an increase in the number of small stems in the burned forests up to 5–9 years after fire because of regeneration patterns, but no differences on larger trees between burned and unburned plots in the long term. In support of MST, after fire, forest structure appears to approximate steady‐state size distribution in less than 30 years. However, our results also provide new evidence that the species recovery of TMCF after fire is idiosyncratic and follows multiple pathways. While fire increased species richness, it also enhanced species dissimilarity with geographical distance. This is the first study to report a long‐term chronosequence of recovery pathways to fire suggesting faster recovery rates than previously reported, but at the expense of biodiversity and aboveground C stocks.     

Progress in the biotechnology of trees

An increasing world population and rise in demand for tree products, especially wood, has increased the need to produce more timber through planting more forest with improved quality stock. Superior trees are likely to arise from several sources. Firstly, forest trees can be selected from wild populations and cloned using macropropagation techniques already being investigated for fruit tree rootstocks. Alternatively, propagation might be brought aboutin vitro through micropropagation or sustained somatic embryogenesis, with encapsulation of the somatic embryos to form artificial seeds. Tree quality could be improved through increased plant breeding and it is likely that experienced gained, to date, in the breeding of fruit species will be useful in devising strategies for forest trees. Since the development of techniques to regenerate woody plants from explant tissues, cells and protoplasts, it is now feasible to test the use of tissue culture methods to bring about improvements in tree quality. Success has already been achieved for tree species in the generation of somaclonal and protoclonal variation, the formation of haploids, triploids and polyploids, somatic hybrids and cybrids and the introduction of foreign DNA through transformation. This review summarizes the advances made so far in tree biotechnology, and suggests some of the directions that it might take in the future.     

In vitro culture and genetic engineering of Populus spp.: synergy for forest tree improvement

Populus species and hybrids are intensively cultivated as sources of woody biomass for the forest products industry and for reforestation of lowlands in temperate regions of the world. However, the long generation time of trees, the presence of seasonal dormancy and the prolonged period required for evaluation of mature traits are strong limitations for classical breeding and selection. The development of methods for in vitro culture and genetic engineering has increased the possibility of producing poplar genotypes improved in insect pest resistance, herbicide tolerance, growth rate and wood quality, or reduction in undesirable traits. Poplar has become a model system in forest tree biotechnology due to several useful features: small genome size, short rotation cycle, rapid growth rate and ease of vegetative propagation. The combination of molecular techniques and classical breeding will help create forest trees with positive effects on the environment. However, risks associated with the biotechnological applications (concerning the impact on biodiversity, long-term adaptation, transgene inheritance and stability) should be carefully evaluated and field tests performed with transgenic poplar.     

Can Management Improve the Value of Shade Plantations for the Endemic Species of São Tomé Island?

Cocoa and coffee are among the most valuable tropical crops, with much of their production in areas of high biodiversity. Although this could suggest a conflict between agricultural expansion and biodiversity conservation, these crops are normally grown in shade plantations—a more biodiversity‐friendly agroforestry system. Using São Tomé Island as a case study, we examined if shade plantation can benefit biodiversity by protecting extinction‐prone island endemic species. We found that shade plantations held rich assemblages, even in comparison with forest: we estimated 30 bird and 74 tree species occurring in plantations compared to 24 bird and 108 tree species in forests. However, the structure of the assemblages was significantly different between ecosystems, with an average dissimilarity of 33.8 percent and 87.9 percent for birds and trees, respectively. Shade plantations had consistently less endemic species than the forest; we estimated a drop from 17 to 13 in birds and from 17 to 3 in trees. We also found that despite marked differences in the response of bird species to the vegetation characteristics of shade plantations, there was a strong positive link between aboveground tree biomass and endemic species richness and abundance. These results show that shade plantations hold assemblages impoverished in endemic species, but that management can improve their value for the conservation of these species. Finally, we suggest that biodiversity‐friendly certification and carbon markets are used to implement and guarantee the long‐term economical sustainability of practices that favor the endemic species in São Tomé's shade plantations.     

Forest plant community as a driver of soil biodiversity: experimental evidence from collembolan assemblages through large‐scale and long‐term removal of oak canopy trees Quercus petraea

Plant–soil interactions are increasingly recognized to play a major role in terrestrial ecosystems functioning. However, few studies to date have focused on slow dynamic ecosystems such as forests. As they are vertically stratified by multiple vegetation strata, canopy tree removal by thinning operations could alter forest plant community through tree canopy opening. Very little is known about cascading effects on soil biodiversity. We conducted a large‐scale, multi‐site assessment of collembolan assemblage response to long‐term canopy tree removal in sessile oak Quercus petraea temperate forests. A total of 33 experimental plots were studied covering a large gradient of canopy tree basal area, stand age and local abiotic contexts. Collembolan abundance strongly declined with canopy tree removal in early forest successional stage and this was mediated by negative effect of understory plant community composition changes, i.e. shift from moss and forb to tree seedling, fern, shrub and grass species. Negative effect of this composition shift on collembolan species richness was largely offset by positive effect of the increase in understory plant species richness. This gives support to both the plant mass‐ratio and functional diversity hypotheses. Collembolan functional groups had contrasting response patterns, which were mediated by different ecological factors. Epedaphic (r‐strategist) abundance and species richness increased with canopy tree removal in relation with the increase in understory plant species richness. In contrast, euedaphic (K‐strategist) abundance and species richness declined with canopy tree removal in early forest successional stage in relation with changes in understory plant community composition and species richness, as well as microclimatic conditions. Overall, our study provides experimental evidence that forest plant community can be a strong driver of collembolan assemblages. It also emphasizes the role of trees as foundation species of forest ecosystems that can shape soil biodiversity through their regulation of understory plant community and ecosystem abiotic conditions.     

Biotechnological efforts for preserving and enhancing temperate hardwood tree biodiversity,health, and productivity

Hardwood tree species in forest, plantation, and urban environments (temperate regions of the world) are important biological resources that play a significant role in the economy and the ecology of terrestrial ecosystems, and they have aesthetic and spiritual value. Because of these many values of hardwood tree species, preserving forest tree biodiversity through the use of biotechnological approaches should be an integral component in any forestry program in addition to large-scale ecologically sustainable forest management and preservation of the urban forest environment. Biotechnological tools are available for conserving tree species as well as genetic characterization that will be needed for deployment of germplasm through restoration activities. This review concentrates on the biotechnological tools available for conserving, characterizing, evaluating, and enhancing hardwood forest tree biodiversity. We focus mainly on species grown for lumber and wood products, not species grown mainly for fiber (pulp and paper production). We also present a brief summary of the importance of non-wood forest products from temperate hardwood tree species (a research area that needs further development using biotechnological techniques) and a few case studies for preserving forest tree biodiversity.