河北小五台山主要植被类型的分布与地形的关系：基于遥感信息的分析

小五台山是河北省最高峰,具有较完整的暖温带植被垂直带谱。本文通过野外群落植被调查,结合由TM遥感影像解译1：50000地形图制作的DEM数据而得到的植被图,分析了小五台山主要植被群落的分布状况及其与地形的关系。结果表明,小五台山从低海拔到高海拔,依次出现灌丛、阔叶林、针阔混交林、暗针叶林、矮林、灌丛、草甸等植被类型。森林景观的面积最大,占总面积的60．7％;平均斑块面积最大的是阔叶林和亚高山草甸,斑块破碎化最严重的是水体和针阔混交林。不同的植被类型在不同的地形条件下分布特点不同,林地在北坡所占面积比例(占总面积的75％)远大于南坡(46%),说明水分条件是小五台山森林分布的限制因子之一;灌丛和草甸与林地相反。随海拔高度的变化,不同植被类型的分布面积比例发生变化,出现替代现象,形成植被垂直带谱。由于坡度的影响,增加了带谱内植被组成的复杂性。     

Effects of forest-floor avalanche disturbance on the structure and dynamics of a subalpine forest near the forest limit on Mt. Fuji

In subalpine forests near the forest limit on Mt. Fuji in central Japan, slush avalanches occasionally destroy forest-floor vegetation through an influx of volcanic gravel from bare upper sites. The vegetation structure of Larix kaempferi–Abies veitchii forests near and distant from avalanche paths was investigated to determine the effects of forest-floor disturbance on successional processes. The Larix population in a forest near an avalanche path, where there had been signs of forest-floor disturbance by avalanches, had a discontinuous age structure with three age groups, indicating that Larix seedlings established under the Larix canopy after the forest-floor disturbance. In contrast, the Larix population in a forest distant from avalanche paths, where there had been no forest-floor disturbance, had a continuous age structure, with no plants younger than the 90-year-old trees, indicating that this population had established on bare ground over a long period. These data suggest that the primary requirement for the regeneration of L. kaempferi on the forest floor is a mineral substrate. Conversely, A. veitchii had a continuous age structure in both forests. However, forest-floor disturbances by avalanche(s) may exclude A. veitchii from the forest because A. veitchii is very sensitive to scoria deposition. In conclusion, forest-floor disturbance by avalanche(s) provides L. kaempferi with an opportunity to establish on the forest floor, resulting in the maintenance of Larix forests alongside avalanche paths in the upper subalpine area on Mt. Fuji.     

Characteristic and representativeness of the vertical vegetation zonation along the altitudinal gradient in Shennongjia Natural Heritage北大核心CSCD

Aims Mountains contain broad environmental gradients, which are to be an outstanding universal value representing significant on-going ecological and biological processes in the evolution and development of zonal vegetation along the elevation gradients. Exploring the biological and ecological value of the vegetation zonation along the elevation gradients of Chinese mountain natural heritage site is important for biodiversity conservation and management. Methods Based on the community survey data of the six vegetation zonation along the elevational gradients in Shennongjia, the global land use dataset, and the literature data of the communities along the altitudinal gradients of other natural heritage sites and the nominated world natural heritage sites in Oriental Deciduous Forest Biogeographic Province by Udvardy, we explored the outstanding universal value of the zonal vegetation along the altitude gradients by the methods of spatial analysis. Important findings Shennongjia heritage site preserves the intact vegetation zonation of the typical Oriental Deciduous Forest Biogeographical Province in the Classification of the Biogeographical Provinces of the World by Udvardy, including evergreen broad-leaved forests (South Slope of the Heritage Site), evergreen deciduous broad-leaved mixed forests, deciduous broad-leaved forests, coniferous and broad-leaved mixed forests, coniferous forests and subalpine shrub and meadow along the elevation gradients. The altitudinal zonation of vegetation in the Shennongjia heritage site represented a variety of bio-ecological processes, such as the turnover of the dominant trees along the altitudinal gradients, and is an outstanding example of the ongoing ecological processes occurring in the development of intact subtropical mixed broadleaved evergreen and deciduous forest in the Northern Hemisphere. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All Rights Reserved.     

岷江冷杉林皆伐后次生群落结构和物种多样性的演替动态

为阐明岷江冷杉林皆伐后次生群落的演替过程,采用空间代替时间的方法,在川西米亚罗林区海拔3100—3600 m的阴坡选择岷江冷杉林皆伐后次生演替10、20、30、40和50a阶段的次生群落作为研究对象,对其群落结构和物种多样性的动态进行了研究。不同演替阶段的树木均呈显著聚集分布。按群落中优势种的重要值将该演替序列划分为3个类型:悬钩子-蔷薇灌丛、白桦阔叶林和桦木-岷江冷杉针阔混交林。随次生演替,乔木和灌木种的物种丰富度趋于增加,而草本种的物种丰富度趋于减少;乔木和灌木种的Shannon-Wiener多样性指数趋于增大,而草本的Shannon-Wiener多样性指数趋于减小;乔木、灌木和草本层的Pielou均匀度指数均趋于增大;乔木层的Simpson优势度指数趋于减小,灌木和草本层的Simpson优势度指数在演替0—40年阶段趋于增大,而在演替50a阶段趋于减小。在该演替序列中,乔木、灌木和草本层的物种组成均呈耐荫种替代非耐荫种的趋势。     

Characteristic and representativeness of the vertical vegetation zonation along the altitudinal gradient in Shennongjia Natural Heritage

Aims Mountains contain broad environmental gradients, which are to be an outstanding universal value representing significant on-going ecological and biological processes in the evolution and development of zonal vegetation along the elevation gradients. Exploring the biological and ecological value of the vegetation zonation along the elevation gradients of Chinese mountain natural heritage site is important for biodiversity conservation and management.Methods Based on the community survey data of the six vegetation zonation along the elevational gradients in Shennongjia, the global land use dataset, and the literature data of the communities along the altitudinal gradients of other natural heritage sites and the nominated world natural heritage sites in Oriental Deciduous Forest Biogeographic Province by Udvardy, we explored the outstanding universal value of the zonal vegetation along the altitude gradients by the methods of spatial analysis.Important findings Shennongjia heritage site preserves the intact vegetation zonation of the typical Oriental Deciduous Forest Biogeographical Province in the Classification of the Biogeographical Provinces of the World by Udvardy, including evergreen broad-leaved forests (South Slope of the Heritage Site), evergreen deciduous broad-leaved mixed forests, deciduous broad-leaved forests, coniferous and broad-leaved mixed forests, coniferous forests and subalpine shrub and meadow along the elevation gradients. The altitudinal zonation of vegetation in the Shennongjia heritage site represented a variety of bio-ecological processes, such as the turnover of the dominant trees along the altitudinal gradients, and is an outstanding example of the ongoing ecological processes occurring in the development of intact subtropical mixed broadleaved evergreen and deciduous forest in the Northern Hemisphere.     

Soil physicochemical properties drive the variation in soil microbial communities along a forest successional series in a degraded wetland in northeastern China

The Sanjiang Plain is the biggest freshwater wetland locating in northeastern China. Due to climate change and human activities, that wetland has degraded to a successional gradient from the original flooded wetland to dry shrub vegetation and a forest area with lower ground water level, which may result in changes in soil microbiologic structure and functions. The present study investigated the microbial diversity and community structure in relation to soil properties along that successional gradient. The soil physico‐chemical properties changed significantly with degradation stage. The Shannon diversity index of both soil bacteria (5.90–6.42) and fungi (1.7–4.19) varied significantly with successional stage (both p < .05). The community structures of soil bacteria and fungi in the early successional stages (i.e., the wetland) were significantly determined by water content, total nitrogen, and available nitrogen concentrations in soils, while those in the later successional stages (i.e., forests) were significantly structured by soil organic carbon, soil pH, and available phosphorus concentrations. These results suggest that the soil microbial structure is mainly determined by soil properties rather than by plant community such as plant species composition along successional stages.     

川西亚高山暗针叶林恢复过程中岷江冷杉天然更新状况及其影响因子

在川西亚高山米亚罗林区海拔3 100~3 600 m阴坡、半阴坡, 以立地条件基本一致的箭竹和藓类林型不同恢复阶段(20~40 a生的箭竹阔叶林、50 a生的箭竹针阔混交林、160~200 a生的箭竹原始暗针叶老龄林; 20~40 a生的藓类阔叶林、50 a生的藓类针阔混交林、160~200 a生的藓类原始暗针叶老龄林)的群落为研究对象, 共设置了50个样方(20 m×20 m), 采用空间代时间的方法分析了岷江冷杉(Abies faxoniana)的天然更新状况, 并采用通径分析法对其影响因子进行分析。结果表明: 箭竹和藓类两种森林类型岷江冷杉幼苗、幼树和小树的密度偏低。对于箭竹林型不同恢复阶段, 岷江冷杉幼苗密度＜幼树密度＜小树密度; 对于藓类林型不同恢复阶段, 藓类阔叶林幼树密度大于幼苗和小树密度, 藓类针阔混交林小树密度大于幼苗和幼树密度, 而藓类原始暗针叶老龄林幼苗密度大于幼树和小树密度。藓类林型岷江冷杉天然更新状况好于箭竹林型。对箭竹林型而言, 影响岷江冷杉天然更新的关键因子为母树密度、倒木蓄积量、箭竹盖度和苔藓层厚度, 其中母树密度和倒木蓄积量对岷江冷杉天然更新起着促进作用, 箭竹盖度和苔藓层厚度对岷江冷杉天然更新起着阻碍作用; 对于藓类林型而言, 影响岷江冷杉天然更新的关键因子为灌木盖度和苔藓层厚度。灌木和苔藓有利于幼苗的发生, 但不利于幼苗向幼树、小树的过渡。     

Structural comparison of tropical montane rain forests along latitudinal and altitudinal gradients in south and east Asia

Geographical patterns of altitudinal zonation, floristic composition, and structural features of tropical montane rain forests were examined along latitudinal gradients in south and east Asia. On equatorial mountains, the tropical montane rain forests occur above 1000 m. Toward middle latitudes, they come farther down and reach sea level at c. 35° N. Thus, the forests are equivalent to the subtropical rain forests of the latitudinal, horizontal zonation series. They exhibit gradual changes in floristic composition and structure along both altitudinal and latitudinal gradients. On equatorial mountains, they are divided into three types, i.e. tropical lower montane, upper montane, and subalpine forests. The three tree regeneration types, having emergent, sporadic and inverse-J type stem-diameter class frequency distributions, coexist in the lower montane forests, but the upper and subalpine forests display only the inverse-J type species with a few species of the sporadic type. Toward the northern latitudinal limit, the distinction between the three tropical montane forest zones in equatorial mountains becomes less clear. This can be explained by temperature conditions: on equatorial mountains, a temperature sum of 85° C months which controls the upper limit of the lower montane forests, and a coldest month mean temperature of-1° C which controls the evergreen broad-leaved trees, appear at c. 2500 and c. 4000 m respectively. The altitudinal range between 2500 m and 3800 m, which is the upper forest limit, is covered by upper montane and subalpine forests. On the other hand, at the latitudinal northern limit, the tropical upper montane and subalpine forests cannot exist because the above mentioned two temperature conditions occur at nearly the same point. Thus, at the northern latitudinal limit of the tropical montane forests, the three zones of equatorial mountains amalgamate into a single subtropical lowland forest community. This is due to the seasonal temperature climate in middle latitudes in, e.g., central Japan and central China.A part of this paper was presented as an oral presentation at the Vth International Congress of Ecology, Yokohama 23–30.8.1990.     

Zonal transition of evergreen,deciduous, and coniferous forests along the altitudinal gradient on a humid subtropical mountain,Mt. Emei,Sichuan, China

Altitudinal zonation of evergreen, deciduous and coniferous forests on Mt. Emei (3099 m asl, 29°34.5' N, 103°21.5' E), Sichuan, China was studied to understand the transition of vegetation zonation from tropical to temperate mountains in humid Asia. On the basis of quantitative data on floristic composition and community structure sampled at ten plots selected in different altitudes on the eastern slope of the mountain, forest zonation and the inter-relationships among different life-forms of trees in each zonal forest community were studied quantitatively. Three forest zones were identified physiognomically along the altitudinal gradient, viz. (i) the evergreen broad-leaved forest zone (660–1500 m asl), (ii) the mixed forest zone (1500–2500 m asl), and (iii) the coniferous forest zone (2500–3099 m asl). Great compositional changes were observed along elevation, and the zonal forest communities were characterized by their dominants and floristic composition. Maximum tree height decreased from 33 m at lower middle altitude (965 m asl) to 13 m near the summit (2945 m asl). There was no apparent deciduous forest zone along the altitudinal gradient, but true mixed forests of three life-forms (evergreen, deciduous, and coniferous) were formed around 2000–2500 m asl. Patches of deciduous forest were found in a lower part of the mixed forest zone, particularly on scree slopes, between 1450 m and 1900 m asl. These patches were dominated by the Tertiary relic deciduous trees, such as Davidia involucrata, Tetracentron sinense, and Cercidiphyllum japonicum var. sinense. High species diversity in the mixed forest zone resulted from the overlapping of different life-forms at middle altitudes, which is partly due to wider variety of temperature-altitude correlations. A comparison of the altitudinal zonation with the other east Asian mountain vegetation clarified that Mt. Emei is located exactly at the ecotone between tropical and temperate zonation types in eastern Asia.     

四川小寨子沟自然保护区大熊猫生境植物群落结构特征

通过沿海拔梯度的系统调查,对小寨子沟自然保护区大熊猫生境的植物群落种类组成和结构进行了初步研究。结果表明:(1)小寨子沟大熊猫生境的植被类型有2种:阔叶林和针叶林;(2)小寨子沟自然保护区内分布有青川箭竹、缺苞箭竹、华西箭竹、冷箭竹等多种箭竹,这些作为大熊猫食料的箭竹广布在各种植被类型中,尤其是针阔混交林和亚高山针叶林;(3)大熊猫对生境的群落结构有较广的适宜性,阔叶林、针阔混交林、亚高山针叶林均可作为它的适宜生境;(4)小寨子沟自然保护区内的植被类型是随海拔的升高而自然过渡的,呈现出受人类活动影响较小的自然状态。     

Litterfall Production Along Successional and Altitudinal Gradients of Subtropical Monsoon Evergreen Broadleaved Forests in Guangdong, China

Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982–2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m⁻² for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m⁻² for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study.     

Altitudinal zonation of human-disturbed vegetation on Mt. Tianmu,eastern China

Much of the primary vegetation at low altitudes has been greatly altered or destroyed by a long history of human activities. This is particularly true in eastern China, where low-altitude areas are now dominated by secondary forests or plantations. Altitudinal vegetation zonation of this region is often based on these secondary forests, resulting in seral vegetation with an obscure zonal sequence. Here, we deduced the potential climax vegetation according to the regeneration patterns of the dominant species of the secondary forests at low altitudes (below 1,000 m a.s.l.) on Mt. Tianmu (1,506 m a.s.l., 30°18′30″–30°21′37″N, 119°24′11″–119°27′11″E). Based on the potential climax vegetation combined with the floristic composition and community structure, three vegetation zones were identified, viz: (1) evergreen broad-leaved forest zone (400–950 m a.s.l.); (2) evergreen and deciduous broad-leaved mixed forest zone (950–1,100 m a.s.l.); (3) deciduous broad-leaved forest zone (1,100–1,506 m a.s.l.). The altitudinal vegetation zones identified in this study correspond with the thermal conditions on Mt. Tianmu. The distribution of vegetation on Mt. Tianmu was limited by lower temperatures in winter, and the altitudinal thermal vegetation zones on this mountain were more similar to the thermal vegetation of Japan than to that of China. The vertical distributions and roles of conifers were different between the eastern and the western regions along 30°N latitude in humid East Asia. Cryptomeria fortunei formed the emergent layer, towering above the broad-leaved canopy at middle altitudes as C. japonica on Yakushima, but disappeared at high altitudes with hydrothermal limitation on Mt. Tianmu.     

Coastal heathland succession influences butterfly community composition and threatens endangered butterfly species

Succession has a strong influence on species diversity and composition of semi-natural open terrestrial ecosystems. While several studies examined the effects of succession on butterflies in grassland and forest ecosystems, the response of heathland butterflies to succession had not been investigated so far. To address this issue we sampled butterfly abundance and environmental parameters on the Baltic island of Hiddensee (NE Germany) along a gradient of coastal heathland succession from grey dunes to birch forest. Our results provide evidence that succession of coastal heathland has a strong influence on butterfly diversity, abundance, and species composition. Thereby grass and tree encroachment present the main threats for heathland butterflies. Diversity and abundance of butterflies were highest in shrub-encroached heath directly followed by early stages of coastal heathland succession (dwarf-shrub heath, grey dune). Both observed threatened species (Hipparchia semele, Plebeius argus) were negatively affected by succession: abundance decreased with increasing vegetation density (both species) and grass cover (P. argus); consequently, the two later successional stages (shrub, birch forest) were not occupied. Our findings highlight the importance of the preservation of early stages of coastal heathland succession for endangered butterfly species. For coastal heathland management we therefore suggest to maintain early successional stages by sheep grazing, mowing or, in case of high nutrient contents, intensive techniques such as sod-cutting or choppering. To a lower extend shrub-encroached sites should also be present, which might be beneficial for overall species richness.     

Genesis of a soil seed bank on a primary succession in the Central Alps (Ötztal,Austria)

Soil seed bank and standing vegetation were investigated on the Rotmoos Glacier foreland (Ötztal, Tyrol, Austria) along the chronosequence (i.e. on the pioneer, early, and late successional stage) as well as on a subalpine pasture beyond the glacier foreland (old successional stage). We aimed to answer the following questions: (1) How large are soil seed banks along the successional gradient? (2) Do the seed banks reflect the actual standing vegetation or do they remember earlier successional stages or do they represent already the next successional stage?     

Secondary Succession and Indigenous Management in Semideciduous Forest Fallows of the Amazon Basin1

To the discussion on secondary succession in tropical forests, we bring data on three under‐addressed issues: understory as well as overstory changes, continuous as opposed to phase changes, and integration of forest succession with indigenous fallow management and plant uses. Changes in vegetation structure and species composition were analyzed in secondary forests following swidden agriculture in a semideciduous forest of Bolivian lowlands. Twenty‐eight fallows, stratified by four successional stages (early = 1–5 yr, intermediate = 6–10 yr, advanced = 12–20 yr, and older = 22–36 yr), and ten stands of mature forests were sampled. The overstory (plants ≥5 cm diameter at breast height [DBH]) was sampled using a 20 × 50 m plot and the understory (plants <5 cm DBH) in three nested 2 × 5 m subplots. Semistructured interviews provided information on fallow management. Canopy height, basal area, and liana density of the overstory increased with secondary forest age. The early stage had the lowest species density and diversity in the overstory, but the highest diversity in the understory. Species composition and abundance differentiated mature forests and early successional stage from other successional stages; however, species showed individualistic responses across the temporal gradient. A total of 123 of 280 species were useful with edible, medicinal, and construction plants being the most abundant for both over‐ and understories. Most of Los Gwarayo preferred mature forests for making new swidden, while fallows were valuable for crops, useful species, and regenerating timber species.     

Anthropogenic disturbances and plant biodiversity in forests of Uttaranchal,central Himalaya

Eight forest types varying in disturbance frequencies were identified along an elevational gradient in Uttaranchal, central Himalaya. Low elevation forests were close to human habitation and had high disturbance frequency, while high elevation forests were situated far from the human habitation and had low disturbance. The dominant tree species at low elevation were Pinus roxburghii and Quercus leucotrichophora, while Q. floribunda and Q. semecarpifolia dominated the high elevation forests. Pyracantha crenulata was the shrub present in all the forests except in Q. semecarpifolia forest and Anaphalis contorta, a herb species, was present in all the forests. Disturbance decreased the dominance of single species and increased the plant biodiversity by mixing species of different successional status. Species richness and diversity for all the vegetation layers were higher in low elevation–high disturbance forests. Mean tree density decreased from high to moderate and increased in low disturbance. The shrub density decreased from high to low disturbance while the reverse occured for herbs. High proportion of early successional species in disturbed forests indicated that disturbance induces succession. The mean number of young individuals increasing from high to low disturbance indicates that disturbance adversely affects regeneration. But, however, the high number of young individuals of Coriaria nepalensis, a small non-leguminous nitrogen fixing tree, in disturbed forests shows that the forest is regenerating. This species could be helpful in the re-establishment of original vegetation through triggering the regeneration of these forests. High elevation–low disturbed forests separated from low elevation–high disturbed forests. Forest type and elevation may have more influence on tree richness while shrub and herb richness may be more sensitive to disturbance and forest types.     

Ecology of the pteridophytes on the southern slopes of Mt. Kilimanjaro – I. Altitudinal distribution

140 taxa of 61 genera in 24 families of pteridophytes were recorded on the southern slopes of Mt. Kilimanjaro. These represent about one third of the entire pteridophyte flora of Tanzania. The families richest in species are the Aspleniaceae, the Adiantaceae, the Dryopteridaceae, the Thelypteridaceae and the Hymenophyllaceae. Due to its luxuriant montane rain forest, which receives a precipitation of up to over 3000 mm, Mt. Kilimanjaro is distinctly richer in pteridophyte species than other volcanoes in East Africa. However, compared with the mountains of the Eastern Arc, the number of pteridophytes on Mt. Kilimanjaro is smaller. This can be explained by the widely destroyed submontane (intermediate) forest rather than by the higher age of the Eastern Arc Mts.The altitudinal distribution of all ferns was investigated in 24 transects. On the southern slopes of Mt. Kilimanjaro they were found in an altitudinal range of 3640 m. Cyclosorus quadrangularis, Azolla nilotica, Azolla africana andMarsilea minuta are restricted to the foothills, while Polystichum wilsonii, Cystopteris nivalis and Asplenium adiantum-nigrum are species found in the highest altitudes.Based on unidimensionally constrained clustering and on the analysis of the lowermost and uppermost occurrence of species, floristic discontinuities within the transects were determined. From these data and from an evaluation of the distribution of ecological groups and life forms, 11 altitudinal zones could be distinguished: a colline zone (–900 m asl), a submontane zone (900–1600 m asl) with lower and upper subzones, a montane zone (1600-2800 m asl) divided into 4 subzones, a subalpine zone (2800–3900 m asl) with lower, middle and upper subzones, and finally a (lower) alpine zone above 3900 m. The highest species numbers were observed in the lower montane forest belt between 1600 and 2000 m altitude. The zonation of ferns found at Mt. Kilimanjaro corresponds well with the vegetational zonation described by other authors using bryophytes as indicators in different parts of the humid tropics.     

Plant diversity patterns in subtropical evergreen broad-leaved forests of Yunnan and Taiwan

The subtropical evergreen broad-leaved forests of Yunnan and Taiwan were compared along environmental and successional gradients with the aim of identifying important taxon and species diversity as well as the drivers of mountain biodiversity patterns. A detrended correspondence analysis of an exhaustive set of data collected from 105 and 223 plots for Yunnan and Taiwan, respectively, was applied to classify natural mature forest types. Additional data from 72 and 68 plots for Yunnan and Taiwan, respectively, were used for analyses of secondary succession. The floristic richness and diversity index were calculated for each type of forest. In Yunnan, the monsoon forests in mesic-humid sites had more taxa and tended to show higher species diversity than the other two forest types. In Taiwan, species diversity values were significantly higher in the Machilus–Castanopsis zone in the middle altitudes (500–1500 m) than for the other three forest zones. For both Yunnan and Taiwan, the forests at the middle successional stage showed significantly higher species diversity than those at the early successional stage. Differences in diversity between the middle and late stages were not significant. These findings highlight the high species diversity of the natural mature evergreen broad-leaved forests of both Yunnan and Taiwan. In the secondary forests, as succession proceeds, species diversity comes to resemble that of the natural mature forests. In both ecosystems, the drivers of species diversity patterns are moisture, altitude, and succession/disturbance.     

Invasion of Ligustrum lucidum (Oleaceae) in the southern Yungas: Changes in habitat properties and decline in bird diversity

Ligustrum lucidum is the major exotic tree in NW Argentina montane forests (Yungas). To assess the effects of its expanding invasion on avian communities we (1) measured different habitat properties (vertical forest structure and composition, vegetation cover, light availability, air temperature, air relative humidity and soil litter depth), (2) compared bird species composition and diversity in Ligustrum-dominated and native-dominated secondary forests and (3) analyzed seasonal patterns and changes in these variables between forest types. The study was conducted during 2010–2011 wet and dry seasons, at two altitudinal zones: 500–800 and 1100–1450 masl. Compared with native forests, Ligustrum dominated forests had a more homogeneous vertical forest structure and denser canopy cover (resulting in lower understory solar radiation), significantly lower understory cover and lower litter depth. Air temperature and relative humidity did not differ between forests in either season. Solar radiation was higher in the dry season in both forest types, but litter depth showed opposite patterns between seasons depending on forest type. We recorded 59 bird species in 21 families. Bird species abundance, richness and diversity indexes were significantly lower in Ligustrum-dominated relative to native forests of similar successional age, which had almost twice as many species as the former. Avian communities differed between altitudinal zones, but the difference was stronger between Ligustrum and native-dominated forests. Avian community composition was less variable in time and space in native forests than in Ligustrum-dominated ones. Our results suggest that L. lucidum invasion generates structurally homogeneous and simpler forests that represent a less suitable habitat for a diverse avifauna. This illustrates the wide ecological changes (from habitat properties and ecosystem functioning to vertebrate community composition) that the subtropical mountain forests of Argentina are experiencing with this invasion.     

Butterfly Community Composition Across a Successional Gradient in a Human‐disturbed Afro‐tropical Rain Forest

Knowledge of the recovery of insect communities after forest disturbance in tropical Africa is very limited. Here, fruit‐feeding butterflies in a tropical rain forest at Kibale National Park, Uganda, were used as a model system to uncover how, and how fast, insect communities recover after forest disturbance. We trapped butterflies monthly along a successional gradient for one year. Traps were placed in intact primary forest compartments, heavily logged forest compartments with and without arboricide treatment approximately 43 years ago, and in conifer‐clearcut compartments, ranging from 9 to 19 years of age. The species richness, total abundance, diversity, dominance, and similarity of the community composition of butterflies in the eight compartments were compared with uni‐ and multivariate statistics. A total of 16,728 individuals representing 88 species were trapped during the study. Butterfly species richness, abundance, and diversity did not show an increasing trend along the successional gradient but species richness and abundance peaked at intermediate stages. There was monthly variation in species richness, abundance, diversity and composition. Butterfly community structure differed significantly among the eight successional stages and only a marginal directional change along the successional gradient emerged. The greatest number of indicator species and intact forest interior specialists were found in one of the primary forests. Our results show that forest disturbance has a long‐term impact on the recovery of butterfly species composition, emphasizing the value of intact primary forests for butterfly conservation.