昆明城区大学校园与公园绿地植物组成研究

目的以种间关系原理为基础,探究河南鸡公山落叶阔叶林中藤本植物是否对林冠下其他物种的生存产生抑制或促进的效应,为理解林冠下的种间关系和共存机制提供指导。方法林冠下藤本及非藤本植物的Shannon-Wiener指数及密度采用样方法进行调查,土壤温湿度采用土壤温湿度监测仪测定。结果该地区落叶阔叶林林冠下总物种及非藤本植物Shannon-Wiener指数随着藤本植物密度的增加而显著下降,林冠下非藤本植物的Shannon-Wiener指数变异受到物种总密度、距离最近树的胸径和土壤温度的综合调节。林冠下非藤本植物的密度随着藤本植物密度的增加而下降,非藤本植物的密度受到物种总密度、土壤温度和距离最近树的胸径大小的影响。结论中国华中地区落叶阔叶林中的藤本植物对林冠下非藤本植物的Shannon-Wiener指数产生显著抑制效应,同时显著降低了个体的数量,这主要归因于藤本植物较强的扩散和生存能力及其对环境资源较强的占据能力,本研究对于提高森林生态系统中物种多样性及共存机制有重要参考价值。     

Colonization lessons from a tropical forest

The decade-old Transamazon Highway provides a useful stage for examining some of the major issues related to frontier conquest and the impact of pioneer settlement on one of the world's richest biomes. The highway project is an ambitious colonization scheme and the lessons that can be drawn from it, ranging from the environmental effects of stripping back the tree cover to the spread of diseases, will be useful in guiding development policy in other tropical regions.     

热带森林植被冠层CO2储存项的估算方法研究

评价植被冠层CO2储存项有助于提高森林-大气层面净生态系统CO2交换量(FNEE)的估算精度.基于西双版纳热带季节雨林2年完整的涡度相关系统和CO2廓线的同步观测资料,详细分析涡度相关法(Fs-EC)和廓线法(Fs-PM)CO2储存项估算结果和变化趋势.结果表明:1)廓线法CO2储存项年平均日变化曲线相比涡度相关法能更...     

Bats limit arthropods and herbivory in a tropical forest

Previous exclosure studies measuring the top-down control of arthropod abundance and herbivory combined the effects of birds and bats. We experimentally partitioned bird predation from bat predation in a lowland tropical forest in Panama and measured the direct effects (arthropod abundance) and indirect effects (herbivory). The exclusion of birds and bats each directly increased arthropod abundance on plants: Bird-exclosed plants contained 65% more, and bat-exclosed plants 153% more, arthropods than controls. Birds and bats also indirectly increased herbivory: Bird-exclosed plants suffered 67% more, and bat-exclosed plants 209% more, herbivory than controls. We conclude that bats have dramatic ecological effects that were previously overlooked.     

Species loss and aboveground carbon storage in a tropical forest

Tropical forest biodiversity is declining, but the resulting effects on key ecosystem services, such as carbon storage and sequestration, remain unknown. We assessed the influence of the loss of tropical tree species on carbon storage by simulating 18 possible extinction scenarios within a well-studied 50-hectare tropical forest plot in Panama, which contains 227 tree species. Among extinction scenarios, aboveground carbon stocks varied by more than 600%, and biological insurance varied by more than 400%. These results indicate that future carbon storage in tropical forests will be influenced strongly by future species composition.     

破碎生境中缙云卫矛种群生殖值分析

卫矛属植物具有杀虫活性,缙云卫矛(Euonymus chloranthoides Yang)为重庆特有的濒危植物,其生境已严重破碎.对该物种位于重庆北碚的6个种群的生殖值进行研究,结果表明,随着种群的减小,种群的生殖值、生活史总生殖值等指标出现增加的趋势,表明种群大小降低,种群增加生殖投入,但当种群太小时,其增加生殖投入的能力受到破坏.缙云卫矛生殖与生存之间表现为对抗关系,较小种群植株的寿命也较小,生殖投入较小的种群具有较长的寿命.说明生境破碎不利于该物种小种群的生殖调节能力.     

Restoration of degraded tropical forest landscapes

The current scale of deforestation in tropical regions and the large areas of degraded lands now present underscore the urgent need for interventions to restore biodiversity, ecological functioning, and the supply of goods and ecological services previously used by poor rural communities. Traditional timber plantations have supplied some goods but have made only minor contributions to fulfilling most of these other objectives. New approaches to reforestation are now emerging, with potential for both overcoming forest degradation and addressing rural poverty.     

Rapid diversification of a species-rich genus of neotropical rain forest trees

Species richness in the tropics has been attributed to the gradual accumulation of species over a long geological period in stable equatorial climates or, conversely, to speciation in response to late Tertiary geological events and unstable Pleistocene climates. DNA sequence data are consistent with recent diversification in Inga, a species-rich neotropical tree genus. We estimate that speciation was concentrated in the past 10 million years, with many species arising as recently as 2 million years ago. This coincides with the more recent major uplifts of the Andes, the bridging of the Isthmus of Panama, and Quaternary glacial cycles. Inga may be representative of other species-rich neotropical genera with rapid growth and reproduction, which contribute substantially to species numbers in the world's most diverse flora.     

Tritium movement in soil of tropical rain forest

Tritiated water applied to the surface of soil in a tropical rain forest was found in free water of the litter and top 18 centimeters of soil as long as 7 months after the application. Plant roots, even in the high-rainfall environment of a tropical rain forest, therefore are exposed to tritiated water for considerable periods of time after release.     

林木遗传图谱构建的技术与策略

对林木遗传图谱构建中的有关概念,实验技术与策略及计算机分析软件等进行了系统阐述。全面总结了当前国内外林木遗传图谱构建研究的现状,指出了目前林木遗传图谱的应用价值及图谱构中存在的主要问题,并对下一步的发展进行了一些探讨。     

红豆树天然林优树选择

应用多目标决策和集对分析原理,对优势木对比树法初选的26株优树预选树进行综合指数计算和比较.复选出一级优树2株,二级优树7株,三级优树14株,可供近期无性繁殖利用.     

林木多倍体育种研究进展

该文综述了林木多倍体育种的途径、方法及其应用现状 ,指出多倍体育种在速生、优质、高抗逆性等林木新品种选育中具有更大的潜力 ;目前在林业生产中应用的多倍体新品种数量之所以相对较少 ,主要与树木细胞遗传等基础研究滞后、一些多倍体育种相关理论和技术难题未能得以攻克有关 .而随着人类对其应用价值认识的提高以及有关新技术方法的注入 ,建立在现代遗传学以及细胞染色体工程技术基础之上的林木多倍体育种将焕发出新的生机与活力 .     

Genetic consequences of tropical second-growth forest regeneration

Secondary forests are more extensive than old-growth forests in many tropical regions, yet the genetic composition of colonizing populations is poorly understood. We analyzed the parentage of a founder population of 130 individuals of the canopy palm Iriartea deltoidea in a 24-year-old second-growth forest in lowland Costa Rica. Among 66 trees in adjacent old-growth forest, only two individuals contributed 56% of the genes in founders. Second-growth trees had lower genetic diversity and larger patches of similar genotypes than old-growth trees. Recovery of genetic diversity of populations in tropical second-growth forests may take many generations and will require continued dispersal from genetically diverse source populations.     

Tree dispersion, abundance, and diversity in a tropical dry forest

Patterns of tree abundance and dispersion in a tropical deciduous (dry) forest are summarized. The generalization that tropical trees have spaced adults did not hold. All species were either clumped or randomly dispersed, with rare species more clumped than common species. Breeding system was unrelated to species abundance or dispersion, but clumping was related to mode of seed dispersal. Juvenile densities decreased approximately exponentially away from adults. Rare species gave evidence of poor reproductive performance compared with their performance when common in nearby forests. Patterns of relative species abundance in the dry forest are compared with patterns in other forests, and are explained by a simple stochastic model based on random-walk immigration and extinction set in motion by periodic community disturbance.     

热带亚热带果树在园林中的应用

介绍了热带亚热带果树在园林绿化中的作用,及其选择原则、应用现状等。     

2019-07期目录

林木无性系育种随着森林工业的兴起而诞生并取得快速发展,在世界林业产业中占具越来越重要的地位。其始终围绕高产、优质的育种目标,通过选择和利用天然群体或人工创制的育种后代群体中遗传增益最为突出的个体,经无性繁殖实现规模生产并适时采收,以满足社会对木材、果实、药物等林产品的巨大需求。由于受树体高大、多为异花授粉,性成熟较晚,生长周期和测试时间长且占地多等限制,决定大多数林木必然在相当长的时期内选择与作物不同的育种策略。现代生物科学和育种技术进步为突破基于传统交配设计杂交育种的遗传改良策略提供了可能。基于种间杂交或异花授粉树种的种内杂交育种时,可采取在毛白杨中成功应用的综合SSR遗传距离和优良单株父本鉴定构建育种亲本群体,并与配子染色体加倍选育三倍体相结合的育种策略,即首先通过SSR分子标记分析林木种质资源库亲本遗传距离,同时采用SSR分子标记对种质资源库自由授粉半同胞家系优株进行父本鉴定,在此基础上通过亲本遗传距离以及半同胞家系优株父本鉴定双重筛选构建育种亲本群体,进而利用高配合力育种亲本开展基于有性多倍化的多倍体育种,并通过无性繁殖实现倍性优势和杂交优势最大限度的利用,经济而高效地推进林木无性系育种进程。