Study on Community Diversity of Coastal Shelter Forest in Jiaonan

Evaluating the biodiversity of previous and current species in a forest community is an important task. Some methodological researches and effective applications have been carried out widely in the temperate upland zone. However, they lack related researches in coastal shelter forests. This paper attempts to analyze them for Jiaonan coastal forest communities from the following three aspects, the relationship between plant biodiversity structure and its environment, the nexus between biodivers…     

Species richness of tree and shrub layers in riparian forests of the Western Caucasus dominated by alien species

The consequences of replacement of native dominants by alien species (Ailanthus altissima, Ficus carica, Robinia pseudoacacia, Acer negundo, and Amorpha fruticosa) in the tree and shrub layers have been studied in riparian forests of the Western Caucasus. The results show that the invasive dominant species do not always achieve higher abundance, compared with native dominants. When this is the case, however, the dominance of alien species as stronger competitors leads to reduction in the species richness of communities, because they not only intercept the greater part of resources from the environment but also provoke increasingly strict partitioning of remaining resources among associated species.     

Characteristics of Carbon Storage and Density in Different Layers of Forest Ecosystems

Characteristics of carbon storage and density in different layers of forest ecosystems should be studied comprehensively and in more detail. Using forest inventory data in combination with field survey data, we explored the characteristics of carbon storage and density in different layers of forest ecosystems in Liaoning Province of China. Results showed that total carbon storage was 813.034 Tg C. The carbon storage of soil layer accounted for 81.0% of the total storage with 658.783 Tg C, followed by those of arbor, litter and shrub layers with 128.403 Tg C (15.8%), 22.723 Tg C (2.8%) and 3.125 Tg C (0.4%), respectively. The average carbon density for the forest ecosystems were 183.571 Mg C ha^–1, with soil layer (148.744 Mg C ha^–1) being the highest one, followed by arbor layer (28.992 Mg C ha^–1), litter layer (5.131 Mg C ha^–1) and shrub-grass layer (0.706 Mg C ha^–1). Carbon storage in different forest ecosystems varied from 1.595 to 319.161 Tg C, while C density ranged from 165.067 to 235.947Mg C ha^–1, with the highest and lowest values being observed in soil layer and shrub-grass layers, respectively, implying that soil is the main body of forest carbon storage. Young-aged forests accounted for a greater proportion of forests in the Province than forests in other age classes; and proper management of forests could increase the carbon sequestration in the forest ecosystems. The comparison with previous estimations of carbon storage for forest ecosystem implied that methods and data used for forest carbon storage estimation affected the results of estimates obviously.     

Species richness,structure, and conservation of <Emphasis Type="Italic">Nitraria retusa</Emphasis> communities in the coastal salt marshes of Kuwait

Although the coastal salt marshes of Arabian Gulf have been altered extensively by human development activities, there is a paucity of data describing changes in the distribution and abundance of native coastal plant communities. The main objectives of this study are to determine vegetation condition, size structure, and conservation status of Nitraria retusa, a medicinal and salt-tolerant shrub, in disturbed and non-disturbed coastal salt marshes of Kuwait. Size measurements of Nitraria shrubs and nabkas, which are mounds of sediment developed around shrubs, were carried out in 50 quadrats (20 × 20 m²), randomly selected inside and outside Sabah Al-Ahmad Natural Reserve. Species richness and soil properties of nabkas and interspaces, the open areas between the nabkas, were also measured. The results revealed that nabkas of Nitraria in non-disturbed sites are more stable and rich in plant diversity than those in disturbed sites. Mean height and mean canopy diameter of Nitraria shrubs, total plant cover, and species richness are significantly higher in non-disturbed sites than disturbed sites, which indicate the positive influences of conservation for long term on vegetation structure and species richness. The results of soil analyses indicate the important role of nabkas in providing refuges for plant life and species diversity. The present study indicates that more than 50 % of the N. retusa community has been lost during the last few decades. Therefore, N. retusa should be considered an endangered species in Kuwait. The reduction in vegetation cover, a decline in species richness, and the overall degradation of salt marshes are attributed to human development activities along the coast of Kuwait. Effective conservation actions for threatened species in degraded coastal salt marshes of this region include establishment of protective enclosures, prohibitions on development that adversely affects native plant communities, and the planting native salt-tolerant shrubs to facilitate regeneration.     

Differences in plant species diversity between conifer (<Emphasis Type="Italic">Pinus tabulaeformis</Emphasis>) plantations and natural forests in middle of the Loess plateau

We compared differences in plant species diversity between conifer (Pinus tabulaeformis) plantations and natural secondary forests in the middle of the Loess plateau. The goal of the study was to examine the differences in the effect of stand development on species diversity and in species responses to changes between forest types and between forest layers. To clarify the effects of differences in forest management, we emphasized the functional types of plant species occurring in each forest type. The result as follow: (1) The H′ and S of tree layer were significantly lower in natural conifer forest than old conifer and secondary forest, but were not different compared with mid aged conifer forest. The H′ and S of shrub layer were significantly lower in mid aged conifer forest compared with other forest types. The H′ of herb layer showed no significant differences in the four forest types. The evenness index (J′) of tree layer of mid aged conifer forest was lower than other forest communities and its J′ of shrub layer was highest although its richness of shrub layer was lower than in the other forest types. (2) The analysis of β diversity index also indicated large differences between conifer plantations and natural forests. Although the tree layer species were similar in old plantation and natural conifer forests, they differed greatly between the natural conifer and secondary forests. The natural conifer and secondary forest species composition in shrub layer differed significantly from those in plantation and secondary plots. Tree species were significantly less common in plantations than in abandoned coppice forests. Species composition in the herb layer of different forest types was similar. (3) The management of P. tabulaeformis plantations alters plant species composition considerably; the number of sub tall-tree species is increased in old aged conifer forest, especially species dispersed by animals. Plantation management appears to affect ecological processes through seed dispersal. From the perspective of management, the change in the structure and composition of the canopy in plantations could affect the behavior of dispersers and regeneration.     

Small mammal communities in forest ecosystems affected by urbanization

A set of characters has been used to evaluate transformations in forest phytocenoses and their small mammal communities affected by urbanization, compared to conditionally undisturbed phytocenoses (communities). In park forests of the city of Yekaterinburg, the understory and subordinate shrub and herb-dwarf shrub layers of phytocenosis are transformed to a greater extent. The undergrowth of conifer forestforming species is as a rule sparse or absent, and that of deciduous trees often consists mainly of invasive species. Small mammal communities in pine forests transformed under the effect of urbanization also undergo changes leading to the formation of relatively stable (for an urbanized environment) zoocenoses differing both in species composition and in parameters characterizing community diversity.     

Influence of aspect and location of stands on biodiversity in a Sal mixed broadleaved forest in Kumaun central Himalaya

In the present study total 21 forest stands on different aspects and locations (Hill base, mid slope and ridge top) on the slope were studied to assess the importance of these two parameters in supporting species regeneration and biodiversity in a mixed broadleaved forest between 380 and 850 m elevation in the Kumauau Himalayan region. A total of 36 tree species were recorded in the forest. In all aspects the tree, sapling and shrub richness was higher at hill base stands in comparison to mid slope and ridge top stand. Maximum tree richness (average across all aspects) was 9.7 and shrub richness was 9.3. Higher richness at hill base may be attributed to more soil moisture and deeper soils which accumulate the hill base where the slope steepness declines. The tree richness was higher in the northern aspect whereas southern aspect was more suitable for the shrub species. From the present study it becomes evident that the base of the hills can support higher biodiversity and are instrumental in supporting regeneration of several tree and shrub species in sal mixed broadleaved forest.     

Forest structure and regeneration along the altitudinal gradient in the Binsar Wildlife Sanctuary,Uttarakhand Himalaya,India

Forest structure and regeneration were studied along the altitudinal gradient in the Binsar Wildlife Sanctuary of Uttarakhand Himalaya in India. Stratified random sampling of tree species was done by placing minimum 15 quadrats of 10 × 10 m at each aspect and altitude. The results reveal that along the altitudinal gradient there were three types of forest communities in the Sanctuary viz., chir pine (Pinus roxburghii), oakchir pine (Quercus leucotrichophora and Pinus roxburghii) and oak (Quercus floribunda and Quercus leucotrichophora). Rhododendron arboreum, Cornus macrophylla and Lyonia ovalifolia were main associates of these forest communities. The oak forests had larger shrub population as compared to chir pine. Myrsine africana was the most dominant shrub across the altitudinal gradient, whereas few shrub species were restricted to a certain altitudinal range. The regeneration of chir pine was best at lower altitude on south and east aspects, which indicates that it mostly regenerates on warm and dry slopes. In general, the regeneration potential in most of the tree species declines with the altitude. The density of saplings and seedlings also represented the dominant species at each altitudinal range, which indicates the cyclic regeneration of forests in the Sanctuary area.     

喀斯特地区土壤水中溶解有机碳浓度对植被退化的响应

按退化程度在茂兰喀斯特地区选取的4种不同植被类型依次为原生性乔木森林、次生性乔灌混合林、灌木林、灌丛草坡,并对各植被退化系统中1a内的土壤水中溶解有机碳（DOC）浓度变化特征进行测试分析,并探讨其对不同退化程度的植被的响应特征。结果显示：（1）各种植被类型下土壤水DOC含量按月份均呈现出由低到高、再由高到低的变化趋势,在6月底出现峰值;（2）土壤水DOC含量对降雨量具有很好的响应关系;（3）土壤水DOC含量随植被退化程度的加剧而呈现出递增的趋势,即退化的植被系统中土壤水的DOC含量大于未退化的植被系统,说明未退化的土壤 植被系统比较稳定,不易受到外界因素的干扰,贮存能力大,流失少。研究结果表明对植被退化响应灵敏的土壤水DOC含量可以作为评价土壤和植被关联退化的一个有效指标。     

Changes in Species Diversity of Rove Beetles (Coleoptera,Staphylinidae) Depending on the Age of Pine Plantations in Central Belarus

Trends of changes in species richness and dominance in staphylinid communities depending on the age of pine plantations have been analyzed. The species richness of these communities is high in the plantations of age classes 1 and 2 (11 and 28 years, respectively) but decreases in the plantations of age class 3 (60 years). The highest and lowest indices of species diversity are observed in the plantations of age classes 2 and 3, respectively. Four groups of rove beetles have been distinguished by the criterion of their dominance in pine plantations of different ages.__________Translated from Ekologiya, No. 4, 2005, pp. 306–313.Original Russian Text Copyright © 2005 by Derunkov.     

Macrozoobenthos as an indicator of the ecological state of mountain watercourses

Structural characteristics of benthic macroinvertebrate communities in mountain watercourses of different sizes have been studied in the Upper Ob basin. It has been found that species richness, diversity of zoobenthos, and most biotic indices in the background areas increase in the series from the smallest watercourses to large rivers. On the contrary, the values of the above parameters in areas polluted with mercury has proved to decrease, thereby indicating a significant transformation of the benthic communities. Approaches are proposed to select reference indices for assessing the ecological state of watercourses in the basin with regard to the size of the river, the structure of benthic communities, and variability of biotic indices along the background cross sections.     

The effect of natural and anthropogenic disturbance in forest canopy and its effect on species richness in forests of Uttarakhand Himalaya,India

Pinus roxburghii (chir-pine) and Quercus leucothchophora (banj-oak) are dominant forests of mountainous part of the Uttarakhand Himalaya. The continued anthropogenic disturbance is opening the canopy, forming canopy gaps and as a result forest fragments are developing. Thus, the present study aims to analyze variations in species richness and vegetational parameters in relation to canopy gaps in forests. Total species richness was greater in open canopied forest compared to moderate and close canopied forests. In comparison between oak and pine forest, it was greater in oak forest while the proportion of common species was low between oak—pine forests. Mean species richness did not significantly vary from one canopy gap to another as well as in oak and pine dominated forest. This indicated that dominant forest types played an important role to form the community structure. The shrubs richness were greater in closed canopy and between the forests it was greater in pine forest. Tree and shrub density was low in open canopy while herb density was high in moderate canopy. Thus, this study indicated that the dominant canopy species play an important role in deciding the community structures especially the distribution of under canopy species. These parameters should be considered for conservation and maintenance of plant biodiversity of a region.     

岷江上游土地岭生态恢复过程中植被特征研究

对岷江上游土地岭生态恢复过程中的群落外貌、物种组成和结构进行了研究。结果表明,恢复后群落外貌以小型叶、单叶、非全缘、草质的高位芽植物为主,表现出与演替前期相符的类似温带针阔混交林特征。恢复形成的四类不同群落组成有一定差异,造林并封育效果最好,干扰下的恢复效果最差。在恢复的进程中,四类群落垂直结构层次更复杂,川莓在各灌木层都占优势地位。放牧干扰是灌木层与草本层物种丰富度与均匀度较低及灌丛难以实现进展演替的主要原因。恢复后群落的上层盖度影响下层盖度,放牧引起了少数口食性差的草本迅速占优。从径级结构上看,处于演替前期的华山松林有被云杉类取代的趋势,加入演替后期种的封育造林是更理想的恢复模式。     

Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in ¹³⁷Cs contamination from 100 to 15500 kBq m⁻² and estimated external dose rates ranged from 0.13 to 30.7 μGy h⁻¹. General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe #7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since ⁹⁰Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by ⁹⁰Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample).     

Structural-functional organization of lower vegetation layers in tree communities of the upper timberline ecotone in the Polar Urals

Typologically identical (dwarf birch-herb-dwarf shrub-moss) open and closed larch forests growing on the same altitudinal transect have proved to differ in the structural-functional organization of lower vegetation layers. Coverage, general species composition, and species richness of the herb-dwarf shrub layer are higher in the open forest than in the closed forest. Correlations between individual species of vascular plants weaken upon transition from the open to the closed forest. Conversely, the coverage of the lichen-moss layer increases in the closed forest, which contributes to its role as a factor of selection of vascular plant species against the background of the prevailing influence of the tree layer.     

Factors of variation in the number of adventive species in herbaceous communities of the Western Caucasus

The saturation of herbaceous communities with adventive species in the Northern Caucasus has been estimated using as an indicator the number of such species in 0.5-m² plots. Among factors accounting for variation in the test parameter, consideration has been given to the coverage of the herbaceous layer, the species richness of communities (in 0.5-m² plots), and the numbers of adventive and indigenous species (in 15-m² plots). The field data have been processes by methods of ordinary and multivariate regression analysis. The results show that variation in saturation with adventive species between small areas of herbaceous communities largely depends on the number of such species in larger areas, their species-holding capacity, and the level of completeness of communities.     

Plant Species Richness and Developmental Morphology Stage Influence Mycorrhizal Patagonia Plants Root Colonization

The objectives of this study were to determine the percentage of root colonization by arbuscular mycorrhizal (AM) fungi at various levels of plant species richness and developmental morphology stages in various perennial grass, and herbaceous and woody dicots species using experimental plots during 2013 and 2014. An auger was used to obtain six replicate root + soil samples at each sampling time on each of the study parameters. Roots were washed free of soil, and percentage AM was determined. The shrub Larrea divaricata was the species which showed the lowest percentage of colonization by AM at the vegetative developmental morphology stage at the monocultures and six-species-mixtures on the experimental plots. Dicots, but not grass, species showed a greater percentage colonization by AM fungi at the greatest (i.e., six-species-mixtures) than lowest (i.e., monocultures) species richness. Although at different degrees of species richness and developmental morphology stages, the perennial grasses Nassella longiglumis and N. tenuis, the herbaceous dicot Atriplex semibaccata, and the shrubs L. divaricata and Schinus fasciculatus showed a greater (p < 0.050) percentage colonization by AM fungi during the second than the first study year. Even though it was species- and sampling time-dependent, percentage colonization by AM fungi increased as species richness also increased most of the times. Our results demonstrated that the plant species differences in percentage colonization by AM fungi in the experimental plots were species richness-, developmental morphology stage-, and sampling-time dependents.     

Effect of three georges reservoir (Yangzi River) on the plant species richness in drawdown zone downstream the tributary river (Pengxihe River)

In order to understand the spatial pattern of plant community and the maintenance mechanism of biodiversity in littoral zone of Three Gorges Reservoir, 110 km stretches of Pengxihe River (from estuary to the backwater of Three Gorges) were chose to study. We investigated species composition and environmental variables along 50 m long stretches of riverbank between the high-water level and the lowest summer water level, at a 5 km interval. The results showed that: (1) along longitudinal gradients, longitudinal species richness, longitudinal shrub species richness and longitudinal herb species richness were significantly related to distance to estuary; (2) along lateral gradient, there were visible different changes in all kinds of types (lateral species richness, lateral tree species richness, lateral shrub species richness, lateral herb species richness). Along lateral gradient, species richness and herb species richness first increased with the elevation then reduced with it, trees and shrubs species richness increased with the elevation. (3) Correlation analyses showed that substrate types were correlated with the longitudinal species richness, without considering the distance to estuary. Soil moisture and substrate heterogeneity were correlated with lateral, species richness. These results indicated that, along longitudinal gradient of the river, distance to estuary plays an important role in species richness, and along lateral gradient spatial heterogeneity due to inundation and flooding plays an important role in forming a new pattern of plant community in the littoral zone of Three Gorges Reservoir Region. Because of special hydrological dynamics, plant in the littoral zone of Three Gorges, are gradually form a unique spatial pattern to some extent, though it had the same change law with riparian plant of a natural river.     

Relationship between Habitat Properties and Composition of Communities in Conifer–Broadleaf Forest

Ecological and phytocenotic features of forest communities were studied in the southwest of Moscow oblast. Based on the ecomorphological groups of species prevalent in the herb–dwarf shrub and moss layers, five groups of communities typical of the conifer–broadleaf forest zone were distinguished (small-herb, small herb-large herb, large-herb, moist-herb, and mixed-herb communities), and their composition was analyzed. Discriminant analysis of the species composition of lower vegetation layers revealed significant differences between the syntaxa, with the percentage of correct classification being 89.8%. To evaluate ecological determination of the above groups of communities, a hypothesis was tested concerning the correlation of their composition with ecotope properties. This hypothesis was verified by means of (1) ordination by ecological indicator values and interpretation of the axes, (2) revealing differences in ecological regimes between habitats of the syntaxa, and (3) combined analysis of on-ground and remote sensing data, particularly spectral brightness of satellite images and morphometric characteristics of the terrain surface. The results confirmed the informativeness of the syntaxa distinguished based on the species composition of the ground vegetation layer and mapping of the ecological regimes of habitats.     

A vegetation management experiment: Goats grazing shrublands in Doñana Natural Park

We have studied the effect of goat grazing on the shrub understory of a pine forest situated in a protected area (Doñana Natural Park). Along three years we have studied the changes in phytovolume, flammability, species richness and diversity in a grazed shrubland and in a control area not grazed by the goats. We studied also food preferences of the goats and the ability of the goats to disperse the seeds of the plants they eat. Goat grazing significantly reduced shrub biomass and flammability, decreasing the risk of forest fire. Goats selected the species they eat, changing the pattern of selection throughout the year. Grazing reduced shrub diversity, but did not affected species richness. The goats can also potentially disperse the seeds of some of the species they eat, since the seeds were able to pass through the goat’s gut and germinated afterwards. Goat grazing on scrub vegetation can be used as an effective tool for the control of shrubs in protected forest areas, without losing biodiversity.