The role of cacao plantations in maintaining forest avian diversity in southeastern Costa Rica

We conducted 600 ten-minute, fixed-radius point counts in two climatically different seasons in forest, abandoned cacao (Theobroma cacao), and managed cacao habitat from September 1997 through April 1998 in the Talamanca lowlands of Costa Rica. A total of 1,464, 1,713, and 1,708 individual birds and 130, 131, and 144 total species were detected in forest, abandoned cacao, and managed cacao, respectively. Independent of season, cacao habitats had a significantly greater number of individuals and species per point than forest. Community similarity analyses based on guild categorizations revealed a significant degree of similarity among all habitats; however, habitat affinity analyses showed cacao habitats having significantly less forest specialists than forest. A multiple linear regression model for actively managed cacao habitat using habitat and landscape variables revealed density and diversity of canopy tree species to be significantly correlated with numbers of forest specialist species detected per point. Although nearest distance to forest was negatively correlated with the number of forest specialist species per point, it was not a significant variable in the model, possibly indicating the complex and unpredictable nature of bird movements within the complex habitat mosaic of Talamanca. The present forest bird community of the Talamanca lowlands is poor in forest specialist species relative to other forested Caribbean lowland sites. The broad patterns of avifaunal distribution illustrated by our results suggest, therefore, that although cacao plantations cannot substitute for forest, they provide habitat for a large number of species which depend to some degree on forests. This revised version was published online in June 2006 with corrections to the Cover Date.     

Zur Ökologie der Arthropodenfauna einer Stadtlandschaft und ihrer Umgebung II. Pflanzengallen und Pflanzenminen

The distribution of 17 dominant gall-inducing arthropods and 12 leaf miners on woody plants was analysed in the city of Kiel and surrounding habitats. The number of species and the diversity of the fauna in the two landscapes did not differ very much.Pemphigus bursarius, Schizoneura ulmi undStigmella argentipedella preferred trees in the city. In the city predominated plant parasites that hibernate on their host plant, while species overwintering in the litter on the ground or in the soil were suppressed. Important habitat factors may be mechanical perturbations near the ground (removal of leaf litter, pavement on the ground, trampling, digging of the soil). The number of species declined with decreasing size of the habitat islands (wood — bushes, hedges — individually growing trees or groups of trees on grassland — road trees), the species hibernating in the vegetation layer were favoured.     

旅游干扰对鸟类多样性及取食距离的影响评价——以普达措国家公园为例

依据普达措国家公园内旅游活动形式的不同分别在公园的步道、观光公路以及不受旅游干扰的村庄进行调查研究。通过在不同的时段内记录鸟的种类、数量、取食距离及对应的客流量和车流量,分析旅游干扰与鸟类多样性及鸟类取食距离之间的关系。研究结果显示:干扰程度不同的3种生境下鸟类多样性也不同,最高为村庄,观光公路次之,旅游步道的鸟类多样性最低;客流量对鸟类多样性的影响很大,而车流量对鸟类多样性的影响较微弱;客流量与鸟类取食距离之间的关系因鸟种的不同而异,对鹬类及白鹡鸰(Motacilla alba)的取食距离的影响大于鸦科鸟类和游禽类。通过不同旅游干扰对鸟类多样性及取食距离的研究,为普达措国家公园的经营和管理提供参考。     

基于MAXENT生态位模型对内蒙古根河地区驼鹿生境适宜性评价

2013～2015年冬季,综合运用动物生态调查、种群生态学和行为生态学等技术,在内蒙古根河林业局共布设71条长约2～4 km样线、调查313个10 m×10 m样方、1 489个2 m×2 m样方、共收集117份粪便,373个驼鹿出现点数据。利用驼鹿出现数据作为分布点数据,选取地形、植被类型等22种因子作为生境变量,利用MAXENT生态位模型分析了深冬时期根河地区驼鹿冬季生境适宜性分布特征和主要生境因子对驼鹿分布的影响。结果表明:模型预测结果准确性较高,平均AUC(area under the curve,受试工作者曲线下面值)值为0.92,Jackknife检验结果显示:驼鹿生境选择的主要影响因子为距道路距离、距火烧迹地距离、距农田距离、海拔、柳、距沼泽距离、距人为活动点距离、距灌丛距离。驼鹿的适宜生境在根河地区呈现连续性分布,主要分布在东部和东北部,从植被类型上看,适宜生境大部分分布于针叶林,且适宜生境的面积为1 155.8 km^2,约占根河研究区总面积的25.6%。     

广东三水云东海国家级湿地公园秋冬季鸟类多样性研究

2019年10—12月,采用样线法在广东三水云东海国家级湿地公园开展秋冬季鸟类多样性调查,共记录到鸟类10目28科56种,数量累计1 875只。其中雀形目鸟类有18科40种,占鸟类总数量的83.25%,非雀形目有10科16种,占鸟类总数量的16.75%。在居留类型中,鸟类数量从高到低依次为留鸟、冬候鸟、夏候鸟、旅鸟。鸟类多样性指数、均匀度指数和丰富度指数的均值分别为3.70、0.78和3.17。云东海鸟类主要栖息场所为湿地公园内的各种生境,但67.42%的鸟类会在稻田生境中栖息和觅食,因此稻田生境利于喜食稻谷鸟类的栖息,当予以保持。适当的人类干扰能促使鸟类多样性,但过度的人类活动则适得其反。因此建议:保护和恢复湿地, 保护现存鸟类, 减少过度人类活动, 保持并适当扩大稻田规模,增加植物多样性, 保护鸟类繁殖栖息, 加强宣传保护教育, 增加园区科研投入等。     

Does the effect of forest roads extend a few meters or more into the adjacent forest? A study on understory plant diversity in managed oak stands

Roads are recognised as having different ecological roles such as barrier, corridor or habitat, but the spatial extent of road effects on plant communities in forests remains unclear. We studied the effect of forest road distance on plant understory diversity at 20 sites in young and adult oak stands in a French lowland forest with a long history of management and road construction. All vascular and bryophyte species were collected at five distances ranging from the road verge to 100 m into the adjacent forest stand. We analysed species composition, individual species response, a priori life-history traits response – life form, habitat preference and dispersal mode – and environmental indicator values in relation to road distance and stand age. Plant composition strongly differed between road verge and forest interior habitats. The main road effect extended less than 5 m into the forest stand. A third habitat was detected at the forest-road edge resulting from the road effect on light and soil conditions, and from edge-specific topography. Non-forest species were almost absent from the forest interior. In contrast, many bryophytes and several vascular plants kept away from the road. We identified a posteriori six species groups that better explained the variability of plant response profiles than a priori life-history traits. Plant response to road distance was also dependent on stand age: some species colonised from the road into the forest interior in young stands following regeneration cutting, while other species displayed the reverse pattern in adult stands once canopy closed above the forest road. Even if the depth of forest road effect measured in lowland managed stands was narrow, building of a new forest road has non-negligible effects on plant population dynamics. Forest managers should take into account the impacts of roads on biodiversity, since the expected intensification of silviculture in response to global changes is set to accentuate the effect of forest roads. We recommend further study on the role of dispersal by vehicles (i.e. agestochory) in road effects.     

放牧对向海蒙古黄榆天然群落春季鸟类多样性的影响

以向海自然保护区内蒙古黄榆天然群落为对象,研究放牧对其鸟类多样性的影响。结果表明：非放牧区、中度放牧区、重度放牧区三种生境,春季栖息的鸟类分别为8目10科12种126只、8目12科15种178只和5目7科9种74只,中度放牧区鸟类多样性最为丰富;在10个生境因子中,天然群落中草本植物的种类数目与鸟类多样性呈正相关关系,是主要的有效预测变量;草本植物种类与放牧强度呈单峰状曲线关系,即随着放牧强度的增加植物生产力将会先增加,直至某一最佳点时达到最大,以后逐渐下降。     

Herpetofaunal species richness responses to forest landscape structure in Arkansas

Species accumulation curves were used to study relationships between herpetofaunal richness and habitat characteristics on four watersheds in Arkansas that differed markedly with respect to management intensity. Selected habitat characteristics were estimated for stands containing the sample points and within buffers with radii of 250, 500 m, and 1 km surrounding the sample points. Richness of all three herpetofaunal groups (amphibians, reptiles, and all herpetofauna) was greater in hardwood forests than in pine or mixed pine–hardwood. For all three groups, the youngest forest age class had the most species. For amphibians and total herpetofauna, richness declined as stand ages increased. Reptiles had the highest richness at sample points with the lowest class of stand basal area (BA), whereas amphibians were richest at points having the highest BA. In contrast to expectations, there was no effect of distance from water on richness of any taxa; however, we may have had incomplete data on the spatial distribution of small ponds outside the sample plots because they were not recorded in the GIS data. Results for distance to roads were ambiguous, but with more separation of compared curves as more plots were sampled, a positive influence of road proximity was suggested. There was a positive effect of buffer age diversity at the 250 m scale for all three herpetofaunal groups, but less so at scales >250 m except for amphibians, which also showed a positive effect at the 1 km scale. The two most intensively managed watersheds had higher species richness than the two less intensively managed watersheds for reptiles, amphibians, and both groups combined. In this study landscape, where urban and agricultural influences were minimal, we did not observe negative impacts of forest management and associated activities, and local habitat heterogeneity created by silviculture often had a positive effect on herpetofaunal species richness.     

Avian assemblages in eucalypt forests,plantations and pastures in northern NSW,Australia

Eucalypt plantations are expanding rapidly in Australia, and their value for native fauna requires investigation. The relative conservation value of young eucalypt plantations was investigated through assessment of avifauna richness, abundance and composition using transect surveys incorporating point counts in five broad habitat types—dryland forests, riparian forests, dryland plantations, riparian plantations, and riparian pastures (strips of riparian vegetation surrounded by pastures). A total of 73 species were recorded during formal surveys. Species richness and abundance were comparable among all habitat types except dryland plantations, which supported fewer species and in lower numbers. The avifauna assemblage differed according to broad habitat types. Forest habitats (dryland and riparian) harboured more forest- and woodland-dependent species, and a greater abundance of nectarivores and insectivores. Riparian plantations supported a similar number of forest- and woodland-dependent species to forest habitats, but also retained some open-country species. Riparian pastures had the highest cumulative species richness, reflecting a diverse mix of forest- and woodland-dependent birds and open-country species. It was the preferred habitat type for granivores and vertebrate eaters. Dryland plantations were dominated by common species and omnivores, and supported fewer forest- and woodland-dependent birds, insectivores and frugivores compared with other habitat types. The presence of riparian strips increased avifauna diversity and abundance in plantations and pastures to a greater extent than predicted by the proportional area of riparian habitat. The importance of riparian habitats needs to be recognised and incorporated into management policies if biodiversity conservation is to be an objective of plantation establishment.     

黑龙江龙凤湿地自然保护区鸟类研究

采用样带法和定点观察法调查黑龙江龙凤湿地自然保护区的鸟类得知：该地区有鸟类142种,隶属于16目33科77属,其中国家一级保护鸟类5种,二级保护鸟类19种;分析鸟类种数和多样性指数的季节变化,以及繁殖期鸟类的组成可知,保护区以迁徙的候鸟为主,繁殖鸟类对湿地生境有高度适应性。     

A study of habitat fragmentation in Southeastern Brazil using remote sensing and geographic information systems (GIS)

The purpose of this work was to study fragmentation of forest formations (mesophytic forest, riparian woodland and savannah vegetation (cerrado)) in a 15,774-ha study area located in the Municipal District of Botucatu in Southeastern Brazil (São Paulo State). A land use and land cover map was made from a color composition of a Landsat-5 thematic mapper (TM) image. The edge effect caused by habitat fragmentation was assessed by overlaying, on a geographic information system (GIS), the land use and land cover data with the spectral ratio. The degree of habitat fragmentation was analyzed by deriving: 1. mean patch area and perimeter; 2. patch number and density; 3. perimeter-area ratio, fractal dimension (D), and shape diversity index (SI); and 4. distance between patches and dispersion index (R). In addition, the folowing relationships were modeled: 1. distribution of natural vegetation patch sizes; 2. perimeter-area relationship and the number and area of natural vegetation patches; 3. edge effect caused by habitat fragmentation. The values of R indicated that savannah patches (R = 0.86) were aggregated while patches of natural vegetation as a whole (R = 1.02) were randomly dispersed in the landscape. There was a high frequency of small patches in the landscape whereas large patches were rare. In the perimeter-area relationship, there was no sign of scale distinction in the patch shapes. In the patch number-landscape area relationship, D, though apparently scale-dependent, tends to be constant as area increases. This phenomenon was correlated with the tendency to reach a constant density as the working scale was increased. On the edge effect analysis, the edge-center distance was properly estimated by a model in which the edge-center distance was considered a function of the total patch area and the SI.     

Characteristics of bird communities between slope and valley in natural deciduous forest, South Korea

本研究在弄清韩国桂坊山(374030N,128301E)天然落叶阔叶林斜坡和山谷中鸟类群落间的特征差异。调查结果表明:两地鸟类群落的种类组成、丰富度、鸟种多样性及群落结构都有不同。森林的垂直结构特别是林下覆被度及胸高直径分布多显不同。两地生境结构的不同必然影响着鸟类对可利用生境的选择。表6图2参19。     

Predicting breeding bird occurrence by stand- and microhabitat-scale features in even-aged stands in the Central Appalachians

Spatial scale is an important consideration when managing forest wildlife habitat, and models can be used to improve our understanding of these habitats at relevant scales. Our objectives were to determine whether stand- or microhabitat-scale variables better predicted bird metrics (diversity, species presence, and abundance) and to examine breeding bird response to clearcut size and age in a highly forested landscape. In 2004-2007, vegetation data were collected from 62 even-aged stands that were 3.6-34.6 ha in size and harvested in 1963-1990 on the Monongahela National Forest, WV, USA. In 2005-2007, we also surveyed birds at vegetation plots. We used classification and regression trees to model breeding bird habitat use with a suite of stand and microhabitat variables. Among stand variables, elevation, stand age, and stand size were most commonly retained as important variables in guild and species models. Among microhabitat variables, medium-sized tree density and tree species diversity most commonly predicted bird presence or abundance. Early successional and generalist bird presence, abundance, and diversity were better predicted by microhabitat variables than stand variables. Thus, more intensive field sampling may be required to predict habitat use for these species, and management may be needed at a finer scale. Conversely, stand-level variables had greater utility in predicting late-successional species occurrence and abundance; thus management decisions and modeling at this scale may be suitable in areas with a uniform landscape, such as our study area. Our study suggests that late-successional breeding bird diversity can be maximized long-term by including harvests >10 ha in size into our study area and by increasing tree diversity. Some harvesting will need to be incorporated regularly, because after 15 years, the study stands did not provide habitat for most early successional breeding specialists.     

兴凯湖不同栖息地水鸟群落差异分析

【目的】研究兴凯湖不同栖息地水鸟特别是濒危鸟类如鹤鹳类群落组成差异,为兴凯湖水鸟保护管理提供科学依据。【方法】于2014年5月至2015年4月、 2017年12月采用直接计数法对湖岗、龙王庙、东北泡子以及青山水库4个区域6类栖息地水鸟群落进行系统调查,并对水鸟群落特征参数进行分析。【结果】兴凯湖湿地内共记录水鸟7目11科85种364 063只。湿地内水域面积最大,物种数最多,多样性指数最高,以雁形目和鸻形目鸟类最多;林地与灌丛面积最少,物种数最少;灌丛多样性指数最低,以鹭科鸟类为主。在4个区域,湖岗水鸟多样性最高,其次是龙王庙和东北泡子,青山水库多样性最低。由于不同区域的栖息地组成不同,水鸟数量存在着显著性差异。【结论】随着兴凯湖栖息地类型的改变与人类活动的加剧,特别是作为鹤鹳类主要的繁殖地龙王庙与东北泡子,农田耕地面积增多,而沼泽湿地与草甸面积减少,使得鸭类与鹤类数量大幅减少。建议需根据不同水鸟对栖息环境的适宜性需求,制定科学合理保护方案,进行有效保护。     

广州越秀公园鸟类多样性及季节动态研究

2008年1月-2008年12月,用路线法对广州市越秀公园鸟类组成及多样性进行了调查,共记录到鸟类41种。其中,国家Ⅱ级重点保护鸟类1种,“三有”鸟类27种。从统计数据来看,越秀公园不同季节之间的鸟类分布有如下特点：春、秋季鸟类无论在种数还是在总体数量上。都多于冬、夏季。其中秋季最多。在所有鸟类中,雀形目的鸟类数置最多,占绝对优势。     

Potential role of frugivorous birds in the recovery process of forest vegetation after feral goat eradication in Mukojima Island, the Bonin Islands

Some introduced frugivorous birds disperse introduced plants and are thus a substitute for extinct native birds. Introduced birds have negative and/or infrequently positive effects on local ecosystems. It is important for management of the ecosystems to understand the relationships between native and introduced frugivorous and plant species. In this study, we elucidated these relationships in Mukojima Island, the Bonin Islands, where was anthropologically deforested and Japanese White-eye Zosterops japonicus and some plants were already introduced. We examined the habitat selection of frugivorous birds, actual dispersed seeds in bird feces, and the distribution of the potentially dispersed plant species. The Japanese White-eye and the native, Blue Rockthrush Monticola solitarius, were dominant on this island. The former mainly used the forest area and dispersed only small seeds and frequently introduced plant seeds. The latter mainly used the open area and dispersed both small and large seeds. Some small-seed plants occurred not only in the forest but also in the open area. Their seedlings were distributed farther from their adult trees than the large-seed species. These indicate that small-seed plants would be more spread than the large-seed plants because the two bird species disperse their seeds in different environments. This introduced bird species may be important in vegetation recovery, although it may contribute to the distribution of introduced plants on this island.     

Community ecology and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracts,Bangladesh

We investigated the floristic composition, woody species diversity and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracks, Bangladesh. We recorded 25 families, 37 genera, 40 species and 1771 woody individuals in a 0.09 ha plot. Euphorbiaceae and Moraceae were the most speciesrich families, and Castanopsis, Ficus and Terminalia were the most species-rich genera. Bursera serrata Wall. ex Colebr. was the dominant species in terms of highest importance value(13%). Trema orientalis(L.)Bl was typically a light demanding species as it appeared in the top canopy with only one individual having the seventh highest IV, but had no regeneration. The expected maximum number of species(Smax) was 140,indicating that many species may invade the forest as the Smax is greater than the recorded total number of species. The nature of the disappearance and appearance of species in the present forest reflects instability of floristic composition. The values of Shannon's index H ′ and Pielou's index J ′(evenness) were 3.36 bit and 0.63, respectively. These values show moderately high species diversity as compared to other subtropical forests in the tropics. In addition, a sample area of 200 m2 in this forest would be sufficient for measuring the diversity indices H ′ and J ′,whereas the trend of J ′may indicate the rate of equality of individuals among the different species decreased with increasing area. The distribution pattern for the total stand was completely random. However, the dominant species showed aggregate distribution for small areas, but random distribution for large areas. The spatial association between species showed that the strongest positive interspecific association occurred between Streblus asper Lour. and Castanea indica Roxb.(ω =0.51). As a whole, most species were weakly associated with each other,of which 58% species associations were completely negative. The result of cluster analysis showed that species pairs were spatially independent at all or most small clusters; stands of species from all clusters are mosaics of complete habitat and pioneer habitat. All patches in this forest community have similar habitat and regeneration niches, which could be a phenomenon for a young growth forest. Thus, the existence of habitat and regeneration niches may be an important factor in the maintenance of diversity in this forest.     

Individual legacy trees influence vertebrate wildlife diversity in commercial forests

Old-growth forests provide important habitat elements for many species of wildlife. These forests, however, are rare where lands are managed for timber. In commercial forests, large and old trees sometimes exist only as widely-dispersed residual or legacy trees. Legacy trees are old trees that have been spared during harvest or have survived stand-replacing natural disturbances. The value of individual legacy trees to wildlife has received little attention by land managers or researchers within the coast redwood (Sequoia sempervirens) region where 95% of the landscape is intensively managed for timber production. We investigated the use of individual legacy old-growth redwood trees by wildlife and compared this use to randomly selected commercially-mature trees. At each legacy/control tree pair we sampled for bats using electronic bat detectors, for small mammals using live traps, for large mammals using remote sensor cameras, and for birds using time-constrained observation surveys. Legacy old-growth trees containing basal hollows were equipped with ‘guano traps’; monthly guano weight was used as an index of roosting by bats. The diversity and richness of wildlife species recorded at legacy trees was significantly greater than at control trees (Shannon index=2.81 versus 2.32; species=38 versus 24, respectively). The index of bat activity and the number of birds observed was significantly greater at legacy trees compared to control trees. We found no statistical differences between legacy and control trees in the numbers of small mammals captured or in the number of species photographed using remote cameras. Every basal hollow contained bat guano and genetic methods confirmed use by four species of bats. Vaux’s swifts (Chaetura vauxi), pygmy nuthatches (Sitta pygmaea), violet-green swallows (Tachycineta thalassina), and the long-legged myotis (Myotis volans) reproduced in legacy trees. As measured by species richness, species diversity, and use by a number of different taxa, legacy trees appear to add significant habitat value to managed redwood forests. This value probably is related to the structural complexity offered by legacy trees. The presence of a basal hollow, which only occur in legacy trees, was the feature that appeared to add the greatest habitat value to legacy trees and, therefore, to commercial forest stands. The results of our study call for an appreciation for particular individual trees as habitat for wildlife in managed stands. This is a spatial resolution of analysis that, heretofore, has not been expected of managers. The cumulative effects of the retention of legacy trees in commercial forest lands could yield important benefits to vertebrate wildlife that are associated with biological legacies.     

Diversity, composition and density of trees and shrubs in agroforestry homegardens in Southern Ethiopia

Diversity of trees and shrubs in agricultural systems contributes to provision of wood and non-wood products, and protects the environment, thereby, enhancing socioeconomic and ecological sustainability of the systems. This study characterizes the diversity, density and composition of trees in the agroforestry homegardens of Sidama Zone, Southern Ethiopia, and analyses physical and socioeconomic factors influencing diversity and composition of trees in the systems. A total of 144 homegardens were surveyed from 12 sites. In total, 120 species of trees and shrubs were recorded of which, 74.2 % were native to the area. The mean number of tree species per farm was 21. Density of trees varied between sites with mean values ranging from 86 to 1,082, and the overall average was 475 trees ha^?1. Four different crop-based enset (Enset ventricosum (Welw.) Cheesman)-coffee homegarden types were recognized and they differed not only in the composition of major crops but also in the diversity, density and composition of trees. The composition, diversity and density of trees is influenced by physical and socioeconomic factors. The major physical factors were geographical distance between sites and differences in altitude of farms. The most important socioeconomic factors were farm size and access to roads. Tree species richness and density increased with farm size. Increased road access facilitated marketing opportunities to agricultural products including trees, and lead to a decline in the basic components of the system, enset, coffee and trees. In the road-access sites, the native trees have also been largely replaced with fast growing exotic species, mainly eucalypts. The decrease in diversity of trees and perennial components of the system, and its gradual replacement with new cash and annual food crops could jeopardize the integrity and complexity of the system, which has been responsible for its sustenance.     

人类干扰对甘肃麻家寺保护站鸟类群落的影响

2004年11月~2005年1月,在兴隆山麻家寺保护站的6种生境(灌木、阔叶林、混交林、针叶林、农田和人工林)中共记录鸟类25种。鸟类物种总数以灌丛和人工林最高,均为15种。阔叶林最低,为10种。鸟类多样性最高的是灌丛,最低的是阔叶林。各种生境中的鸟类组成和优势物种差异较大,建议每种生境均保持一定面积,以便保护鸟类物种多样性。