生态学中关键种与物种重要性的概念(英文)

在本文中,对关键种的概念进行了讨论,并介绍了关键种的典型特征及其在群落和生态系统中的判别。在对关键种的研究基础上,首次提出了物种重要性(SI)概念。物种重要性可以简单地理解为生态系统中物种的重要值,它由三个指数构成,即物种结构重要值(SIV)、功能重要值(FIV)和动态重要值(DIV)。本文同时评价了三大硬阔森林生态系统中乔木树种的物种重要性。     

科学引进外来物种正确防治物种入侵

外来物种是当今生物多样性保护的一个重大话题。作者提出了外来物种主要集中在大中城市及周边农村;分析了湖南省外来物种分布现状;提出了正确认识外来物种,科学利用外来物种,建立起立法、检疫、监测等综合防治体系,不断提高防治外来物种入侵的能力和意识,逐步完善防治外来物种入侵的法律制度。     

Biomass component equations for Latin American species and groups of species

? Studies dealing with the estimation of biomass, site productivity and the contribution of forests to the global carbon balance require the use of allometric equations. There have been a great number of equations developed to estimate biomass components of trees and shrubs in various ecosystems. However, there are less literature compilations that address the calculations of biomass components.

? I report a total of 229 sets of allometric equations to estimate biomass components for 102 species in 72 different forest communities of arid, semi-arid, subtropical, tropical and temperate Latin-American ecosystems.

? The selection of the appropriate allometric model is a key element in the accurate estimation of biomass, stand productivity, carbon stocks and fluxes, and as a consequence, it is important to apply special effort to the selection and estimation of biomass equations.

? I also discuss statistical methods of parameter estimation and recommend the dissection of two conventional allometric equations when biomass studies are conducted on a wide range of diameters. In order to use nondestructive procedures of biomass estimation such as the fractal theory, the null hypothesis that the mean slope b value is equal to 2.67 was rejected for Latin American biomass species.

? This information is critical for the establishment of environmental projects that aim to estimate conventional parameters (i.e., productivity, habitat quality and fuel wood) as well as environmental features (i.e., stocks and fluxes of carbon and nitrogen).

     

关于增加造林物种的多样性引进优良树种的建议

在"天然林保护工程"的启动实施中,增加新的造林树种,丰富林木优良基因也是不可忽视的问题.大兴安岭地区由于气候比较寒冷,无霜期短,可供造林树种比较单一,在一定程度上制约了林业工作的发展,为此,加快林木引种的进程,实现此地区造林树种的多样化,促进林业事业的发展,增加林产品的种类,提高森林的稳定性及抗性,充分发挥森林的防护作用和森林美化、净化价值,更好地为林区经济建设服务具有十分重要的意义.     

Structure and species composition of novel forests dominated by an introduced species in northcentral Puerto Rico

The African tulip tree, Spathodea campanulata Beauv., is an introduced species forming novel forest types in Puerto Rico. These forests develop naturally after deforestation, agricultural use and land abandonment, and there are many questions as to their ecological characteristics. We sampled structure and species composition of large, small, and juvenile trees (≥10, ≥2.5 to <10, and <2.5 cm diameter at breast height, respectively) in nine secondary forests dominated by S. campanulata on alluvial, karst, and volcanic substrates in northcentral Puerto Rico. No differences were found in S. campanulata forest structure between substrates. Of a total of 79 species found, 17 were introduced. Forests on karst and alluvium had the highest and lowest global species richness, respectively. Species richness increased from large to small to juvenile trees in most sites, but more so on karst. The percentage of introduced species was inversely related to species richness of tree size classes on all substrate types. The dominance of S. campanulata in the large tree size class was highest and lowest in alluvial and volcanic sites, respectively, and decreased from large to small to juvenile trees on all substrate types. Species richness of S. campanulata forests is lower than that of native forests on equivalent substrates. Although land use history affects composition, the juvenile tree species established in S. campanulata forests seems to correspond to the geological substrate were sites are found. This study shows S. campanulata restores forest structure and native tree species on abandoned agriculture and grazing lands in Puerto Rico. Management of these novel forests should consider them as resources were natural processes have the potential of making them more diverse.     

Neutral and accumulator species in determining the spatial structure of tree species at different spatial scales

In 2014, a 40-ha undisturbed plot was established in the Beijing Songshan Nature Reserve. The spatial distribution and spatial associations of five dominant tree species of different height classes were examined using spatial point pattern analysis and the effects of these species on local community diversity assemblages were examined using the ISAR method. The dominant species were characterized by an aggregated distribution at spatial scales of 0–50 m. At smaller spatial scales, trees in larger height classes had significant positive and negative effects on the diversity of the lower height classes. However, at larger spatial scales this effect was diminished. At small scales(0–10 m), accumulator species had positive effects on species diversity, maintained an over-representative proportion of diversity in their proximity, and supported the ecological niche theory. At the larger scale(10–50 m),neutral species were dominant and had positive effects on species diversity, though repeller species, which had negative effects on species diversity, also contributed to diversity. Neutral and accumulator species together determined local species diversity, but the relative importance of the two was closely related to spatial scale. A combination of the ecological niche theory and neutral processes together determines species coexistence and biodiversity of an undisturbed pine forest.     

Vertebrate species assemblages and species sensitivity to logging in the forests of north-eastern New South Wales

The occurrences of 227 vertebrate species recorded on 487 forested sites in north-eastern New South Wales were investigated to determine the levels of association among species, the distribution of species by broad functional groups, species relations with key environmental and disturbance variables, the sensitivity of species to intensive logging, and to list species that have potential value as direct indicators of major environmental change and which should be considered as candidates for long-term monitoring.A total of 40 species appeared to be significantly disadvantaged by logging, another 40 species appeared to be significantly favoured by logging, while the remainder (147 species) appeared to be relatively unaffected. Most species were widely distributed throughout both logged and unlogged landscapes, albeit at possibly quite different abundances. This may be due to the fine-scale complexity of the habitat mosaic for many species, resulting in the continued availability of essential resources within or near logged areas, or the lack of sufficient sensitivity in the analysis due to the need to use presence–absence data. A further 121 species were recorded so rarely in the study (based on 619 sites) that it was not possible to make any assessments of their sensitivity to logging. The study produced several unexpected results, including the failure to identify some species as sensitive to logging that had previously been identified as sensitive in experimental and other retrospective studies.Species disadvantaged by logging were often either dependent on large old trees and/or tree hollows for nesting, roosting and foraging, such as the Common Brushtail Possum, Red-browed Treecreeper, Satin Flycatcher and Crimson Rosella, or they were species that inhabit open forests and woodland, such as the Rufous Bettong, Buff-rumped Thornbill, White-throated Gerygone, White's Skink and Nobbi, that were probably disadvantaged by the increase in stem density and understorey and mid-canopy cover that usually follows logging. In contrast, species favoured by logging, such as the Eastern Whipbird, Brown Gerygone, Lewin's Honeyeater, Wonga Pigeon and Land Mullet, were often those species preferring wetter forest environments, particularly those with multi-layered foliage and a forest structure that includes fallen logs and a dense ground cover. No species displayed consistently strong preferences for selectively logged forest. Mammals were more likely to be disadvantaged by logging than birds, but reptiles contained the largest proportion of species sensitive to logging (39%). Frogs were inadequately sampled in this study; only nine species were recorded. While each taxonomic group had some species that were apparently sensitive to logging, the time frame to population recovery following logging disturbance may differ widely between groups depending on their habitat requirements. Fire history was also strongly correlated with the occurrences of many species, indicating the need to quantify species sensitivity to regular fuel-reduction burning.Three main assemblages of species were identified. One group consisted of rainforest or wet forest specialists, another group comprised open-forest generalists, including a number of open-country and woodland species, and a third group was made up of tall, eucalypt forest generalists, including all of the large forest owls and marsupial gliders. Each broad assemblage, and most of their sub-groups, were found to have at least one species that was apparently sensitive to logging. The study was unable to test whether these sensitive species can function effectively as indicators of the changing status of other species within each assemblage because sampling was undertaken only once at each site.This study has provided one of the few opportunities to date to critically evaluate some aspects of the indicator species concept and its potential as a management shortcut for assessing changes in biodiversity in managed forest landscapes. Qualified support for the concept has been shown, based on the identification of a set of species apparently sensitive to logging and their representation across a range of species assemblages. The choice of candidate species for monitoring will depend on the integration of results from other experimental and retrospective studies, and will be specific to each region depending on the composition of species assemblages and the goals of management.     

Ecology and distribution of Armillaria species in Norway

The occurence of Armillaria species was assessed in Norway, enabling the northern‐most distribution of this genus to be determined in Europe. Four Armillaria species were found in Norway. Armillaria borealis was the most common species occurring on woody vegetation to the permafrost zone (ca. 69°N). Armillaria cepistipes was present in southern and central Norway, but was not found further than 66°N. Armillaria solidipes and Armillaria gallica were rare, found at only one locality each; 59°40′ and 59°32′, respectively. Armillaria species were found on 14 hosts, but there was no significant difference between occurrence of A. borealis and A. cepistipes on declining and dead trees. Phylogenetic analyses separated each species into separate clades. All isolates of A. borealis, except one, and most isolates of A. solidipes were in separate clades. However, a subclade within the A. borealis clade was formed of two A. ostoyae and one A. borealis isolates. Two small A. cepistipes genets were found in a declining oak stand.     

Distribution and ecology of Armillaria species in Greece

Five Armillaria species were identified in a nationwide survey in Greece. Armillaria mellea was present in coniferous and broad-leaved forests in most of the areas examined, except the high altitudes (above 1100 m) of the mountains of north Greece. It was found to cause significant damage in fir forests as well as in fruit orchards and vineyards. Armillaria gallica was common in coniferous and broad-leaved forests in the high altitudes of central and northern Greece, predominating in the beech forests. The fungus was a weak parasite or a saprophyte of forest trees and was occasionally found on cultivated plants. Armillaria ostoyae was not found in southern and central parts of the country, but it has a wide distribution in the mountain forests of northern Greece and causes significant damage on fir, black pine, Scots pine and spruce. Armillaria cepistipes was recorded at high altitudes (1400–1800 m) on two mountains of northern Greece, mostly as a saprophyte in coniferous and broad-leaved forests. Armillaria tabescens was rare in the forests of Greece; it was found to cause disease in almond tree orchards.     

四川四季桂品种群品种调查与分类

对四川省几个栽培桂花的主要城市四季桂品种进行了调查和整理,共记载了6个四季桂品种.编制了四季桂品种群各品种分类检索表并对各品种进行了特征描述.     

四川立地分区及适生树种

在划分立地区的基础上，根据地形、地貌、海拔、土壤、植物、气候等因子，参照有关资料，划分立地亚区、立地类型小区和立地类型组，并提出适生树种，为各地进行退耕还林地的造林规划提供理论参考。     

The Armillaria species in Europe

A literature survey is given of the five European honey mushrooms Armillaria mellea, A. borealis, A. bulbosa, A. cepistipes, and A. obscura (syn. A. ostoyae) (corresponding respectively to Korhonen's intersterile groups D, A, E, B, and C); two forms of A. cepistipes are discussed: the tiny A. cepistipes f. cepistipes from Czechoslovakia and West Germany and the more common A. cepistipes f. pseudo-bulbosa Romagnesi et Marxmüller. Nomenclature, geographical distribution, hosts, some characteristics, and practical importance (including pathogenicity) are treated.     

Diversity of secondary woody species in relation to species richness and cover of dominant trees in thermophilous deciduous forests

One of the prominent compositional features of thermophilous deciduous forests of southern Europe is their richness in secondary woody species (AWS). To date, no studies have focused on the diversity and contribution to the ecosystem functions and socio-economic benefits provided by these species. Here, we first characterized species richness and diversity for three main functional groups of AWS, sporadic trees, shrubs and vines, in 53 representative stands of central Italy. Secondly, we explored variations in AWS diversity and composition along a four-level gradient of species richness of dominant trees under comparable site conditions. The 40 AWS taxa recorded showed a remarkable taxonomic singularity at both the genus and the family rank. Dominant tree species richness had no significant effect on AWS species richness and composition, while Shannon diversity of AWS, especially shrubs, was associated with cover of the dominant trees. Each AWS possessed, on average, ca. five ability traits over a total of 13 considered that contributed to important ecosystem functions or expected socio-economic benefits such as wood and food production, conservation of genetic resources (wild crop relatives) and ornamentals. This highlights the key role of AWS, and in particular of sporadic trees, for enhancing multifunctionality of thermophilous deciduous forests.     

Ecological niche complexity of invasive and native cryptic species of the Bemisia tabaci species complex in China

Journal of Pest Science - Bemisia tabaci is an important pest affecting agricultural and horticultural crops worldwide and comprises a complex of cryptic species. In China, the introduction of the...     

Insect herbivores and pathogens of Alnus species in Uganda

Published documentation of insect pests and pathogens associated with Alnus species in Africa is very scarce. We surveyed damaging insects and pathogens, and arthropod natural enemies on Alnus acuminata and A. nepalensis in Kabale and Mbale districts, Uganda between March 1999 and August 2000 in order to identify the range and relative abundance of arthropods and pathogens associated with the Alnus species. Frequently encountered damaging insects on the Alnus species included Apis mellifera, Apion globulipenne, a Systates sp. (Coleoptera: Curculionidae), Phymateus viridipes, a Lobotrachelus sp. (Coleoptera: Curculionidae), Coloborrtics corticina and some Chrysomelidae. Some species such as Aphis fabae, Parastictococcus multispinosus and a Cacopsylla sp. (Homoptera: Psyllidae) were observed feeding on other agroforestry tree species and/or crops although they generally occurred at low population intensities. Spiders and parasitic Hymenoptera were the most common natural enemies. Diseases were more severe in nurseries than in the field. Damping-off caused by Fusarium oxysporum, Septoria brown leaf spot and stem canker were the most serious diseases of Alnus. The array of damaging insects and pathogens indicates a potential danger to the cultivation of Alnus species in Uganda as adoption of the species for agroforestry continues to expand in the country. In view of the increasing demand for Alnus species for agroforestry in Uganda, regular pest monitoring and appropriate control strategies are necessary.This revised version was published online in November 2005 with corrections to the Cover Date.     

Growth and yield of nine pine species in Angola

A species introduction experiment including several tropical pines and eucalypts was established in 1966/1967 in the Tchianga research station in Angolan Highlands. Despite 27 years of political conflict (1975-2002) and lack of management, the research experiment has remained relatively well conserved. We measured the best conserved plots that were 41 years old in 2007 to obtain information on the growth of different pine species. We calculated stand characteristics including basal area, dominant height, mean diameter, and stand volume for Pinus patula Schiede ex Schiltdl. Et Cham., Pinus pseudostrobus Lindl., Pinus kesiya Royle ex Gordon, Pinus devoniana Lindl., Pinus chiapensis (Martinez) Andresen, Pinus elliottii Engelm., Pinus greggii Engelm. Ex Parl., Pinus montezumae Lamb. and Pinus oocarpa Schiede ex Schltdl. The growing stock volume at 41 years was the highest in P. pseudostrobus, 1,325 m3·ha-1, followed by P. kesiya with 1,200 m3·ha-1. The widely planted P. patula had a growing stock volume of 892 m3·ha-1. P. oocarpa and P. pseudostrobus had the highest stand basal area, over 80 m2·ha-1. Using increment core analyses we studied the temporal development of stand characteristics. Analysis of the mean annual increment (MAI) showed that rotation lengths of 20-30 years would maximize wood production. With these rotation lengths, the MAI of P. pseudostrobus would be 35 m3·ha-1. Other productive species were P. kesiya, P. oocarpa and P. chiapensis. P. patula had a maximum MAI of 20 m3·ha-1. P. greggii had the lowest mean annual volume production, only about 13 m3·ha-1.     

常用绿化树种易发生的专食性害虫及防治措施

对近年来在我省大发生或局部发生、危害较重的10余种食叶或蛀干害虫的易害树种进行了调查,并对害虫的生活史、习性进行了研究,提供了防治措施。为生产及园林绿化管理部门针对某种害虫进行有效防治,提供了依据。