Species Diversity Based on Vertical Structure as Indicators of Artificial Restoration for Coniferous Forests in Southwest China

Five indices of species richness, species diversity and species evenness were used to assess a diversity of four types of coniferous forests undergone different artificial regeneration time. The study was based on the vertical structure of forests, involving growth-forms of total plants as well as vertical layers of woody plants. The results showed that, except for the fourth layer of woody plants, the vertical structure of the four forests exhibited significant difference in terms of their species richness, species diversity and species evenness, suggesting that a species diversity index provided more detailed information and was a better index reflecting the regeneration processes in this region. It was recommended that silvicultural management of artificially regenerated forests should be strengthened to conserve the biodiversity of the forests, optimize forest structure and, in the long run, promote sustainable development of forest ecosystems.

Composition, diversity and distribution of tree species in response to changing soil properties with increasing distance from water source – a case study of Gobind Sagar Reservoir in India

Construction of big dams on rivers develops artificial lakes or water reservoirs which conceive alterations in soil properties of the upstream catchment area. An undulating topography and freckly soil properties cause ups and downs in tree diversity, composition and distribution. The study aimed to evaluate the effect of Gobind Sagar reservoir on soil properties relative to the distance from it and assess its effect on tree diversity, evenness and their distribution in tropical and subtropical forests. Based on data analysis it was found that the soil moisture and organic carbon decreased along with increasing distance from the reservoir. It played a significant role in varying tree diversity. The sites distributed within0-2 km showed significantly higher α and β-diversity indices. Tree species richness and diversity indices showed a strong correlation（p ＆lt; 0.05） with soil moisture and organic carbon content. Simpson＇s and Mc Intosh evenness indices showed a strong negative correlation with soil bulk density. Indirect Detrended Correspondence Analysis（DCA） identified soil moisture and soil organic carbon as two major environmental gradients that influenced tree diversity and their distribution in five tropical and four subtropical forests in an upstream catchment of the reservoir. Mixed forests inhabited moist sites andAcacia-Pinus forests showed an inclination to dry areas. Canonical Correspondence Analysis（CCA）revealed that the tree species in tropical forests were mainly affected by driving forces such as soil moisture,organic carbon and bulk density whereas, in subtropical forest tree species were influenced by elevation, soil p H, EC and clay content.

Pedodiversity: a controversial concept

The concept of pedodiversity and its measurement methodology proposed and developed by Ibá?ez research term is introduced. An attempt to apply pedodiversity to analyze spatial soil variation and distribution patterns on the global scale is briefly demonstrated. Furthermore, constructive comments and criticisms on pedodiversity and its measurement from the noted pedologists and ecologists are outlined. Finally, potential applications of pedodiversity in soil science and other relevant disciplines are discussed.

Carbon fluxes and species diversity in grazed and fenced typical steppe grassland of Inner Mongolia, China

Aim Grasslands are dominant vegetation of China,support outstanding biodiversity and sequester bulk amount of atmospheric CO_(2).These grasslands are highly degraded and fragmented due to remarkable anthropogenic and grazing loads.Chinese Government has made great attempt to restore by grazing exclusion.The relations of carbon fluxes with species composition and diversity in the communities sensitive to grazing by large herbivores are needed to be analysed under the global climate change scenario.The objective of present study was to comprehend the effects of grazing and fencing on the ecosystem structure and function of the typical steppe grassland.Methods To meet the objectives,overgrazed and fenced(since year 2001)sys-tems were selected in typical steppe grassland at the Duolun Restoration Ecology Research Station,Inner Mogolia,China.Within each system,three dominant communities with three replicates were selected.In each replicate community,three 1×1 m plots,were randomly located.Each plot was divided into four 50×50 cm quadrats.A total of 216,50×50 cm quadrats were sampled.From each quadrat,number of individuals and above-ground herbaceous biomass for each species,soil respiration(SR),ecosystem respira-tion(ER),net(NEE)as well as gross(GEE)ecosystem CO_(2) exchanges were recorded in June 2015.Data were well analysed using statistical software.Canonical correspondence analysis showed dif-ferential responses of communities to the structure and function of the typical steppe grassland.Important Findings Across the communities,fencing reduced the soil tempera-ture by 12%and at the same time increased the soil moisture by 44.30%,thus,increased the species richness by 28%,evenness by 21%,above-ground biomass by 19%and plant carbon by 20%.Interestingly,fencing increased NEE by 128%,GEE by 77%,SR by 65%and ER by 39%.Under fencing,species composition partially governed the CO_(2) exchange processes.Conclusions Fencing reduces soil temperature and thereby improves species diversity and more efficient CO_(2) sequestration and long-term and in-depth study is desirable for a better understanding of the relation-ship between species diversity and ecosystem carbon uptake.