Abstract:Rhinopithecus roxellana’s habitat condition is directly related to its long-term survival and reproduction. Research, with large-scale, on R. roxellana’s habitat selection of seasonal changes is conducive to the protection and construction of its habitat, and it is essential protecting the rare species. Our research is based on the results of previous studies in biological and behavioral ecological field. With the support of GIS and RS technology, we conducted a lot of field investigations. In addition, we also took R. roxellana’s selection bias of seven kinds of ecological factors into consideration. Through the above efforts, we got a selection intensity distribution layer about R. roxellana’s habitat selection of seasonal changes. Our study shows that in spring, the area of weak intensity is 1507.96 hm² while less weak area is 33868.72 hm². The strong intensity area is 266 hm² while the less strong area is 36818.84 hm².
In summer, the area of weak intensity is 4683.4 hm² while less weak area is 28392.4 hm². The strong intensity area is 4078.52 hm² while the less strong area is 35307.2 hm².
In autumn, the area of weak intensity is 1972.08 hm² while less weak area is 33254.72 hm². The strong intensity area is 1516.84 hm² while the less strong area is 35717.88 hm².
In winter, the area of weak intensity is 542.76 hm² while less weak area is 28230.84 hm². The strong intensity area is 392.44 hm² while the less strong area is 43295.48 hm².
The results show that the most forestry areas of the Shennongjia Mt. lie in strong intensity area and these areas provides optimal habitat for the Snub-nosed Monkey.
The distribution layer analyses show that eastern part of the Shennongjia area is coincidence with the current natural distribution of the Snub-nosed Monkey, whereas north-western, south-western and southern part of the area is located in the weak intensity areas and is unfit for the Snub-nosed Monkey. In the central part, the strong intensity areas are fragmented by the highways and no Snub-nosed Monkey is found in this highly disturbed area. However, it is probably a potential habitat for the Snub-nosed Monkey.
Survival and reproduction of the Snub-nosed Monkey was ensured by large and continuous habitat in the eastern part of the Shennongjia Mt. Much effort is needed to intensify the connection of the fragmented central area of the Shennongjia Mt.

Abstract:Global climate change is one of the most important issues of contemporary environmental safety. Quantifying regional or global greenhouse gas (GHG) emissions and searching for appropriate mitigation measures have become a relatively hot issue in international global climate change studies. The high temporal and spatial variability of GHG emissions from soils makes their field measurement at regional or national scales impractical. To develop emission factors for a wide range of management practices such as those given in the Intergovernmental Panel on Climate Change Tier I methodology are often considered as a convenient technique to estimate emissions, but these can result in substantial errors when applied to specific geographical regions. Accordingly, considering the complexity of greenhouse gas production in soils, process-based models are required to quantify and predict the GHG emissions, and also interpret the intricate relationships among the gas emissions, the environmental factors and the ecological drivers. Several detailed biogeochemical process-based models of GHG emissions have been developed and accepted in recent years to provide regional scale estimate of GHG emissions and assess the mitigation measures. Among these the DNDC (Denitrification–Decomposition) model, as a process-based biogeochemical model, is capable of predicting the soil fluxes of all three terrestrial greenhouse gases: nitrous oxide (N₂O), carbon dioxide (CO₂), and methane (CH₄), as well as other important environmental and economic indicators such as crop production, ammonia (NH₃) volatilisation and nitrate NO₃^- leaching. Originally developed as a tool to simulate GHG emissions generated from agro-ecosystem, DNDC has since been expanded to include ecosystems such as rice paddies, grazed pastures, forests, and wetlands, and the model has attracted worldwide attention to simulate carbon and nitrogen biogeochemical cycles occurring in global ecosystems. This paper introduces the scientific basis underlying the modeling of greenhouse gas emissions from terrestrial soils, brings together the worldwide research undertaken on a wide range of ecosystems to test and verify, improve and modify, and apply the DNDC model to estimate GHG emissions from these systems, and furtherly sums up the advantages and disadvantages of the model for providing a reference for the application and development of the model. Most studies showed that there was a good agreement between the simulated and observed values of CO₂, CH₄ and N₂O emissions from arable, forest and grassland fields at different geographical locations over the world. However, some discrepancies still existed between observed and simulated seasonal patterns of CH₄ and N₂O emissions. Moreover, the DNDC model was mainly tested against experimental data on GHG emissions, but there were a few validations on NO₃^- leaching, soil water dynamics, NH₃ volatilisation which could greatly impact the GHG emissions. With the high development of society and economy, China had been facing a huge challenge between food production and environmental protection. Therefore, it was an urgent task to search optimal measures for optimizing land resource use, increasing crop productivity and reducing adverse environmental impacts. Process-based biogeochemical modeling, as with DNDC, can help in identifying optimal strategies to meet the needs. In future, the DNDC model need to not only improve the capability of predicting the GHG emissions, but also the accuracy of simulating the NO₃^- leaching and soil water dynamics for quantifying the non-point source pollution through modifying the parameters of the model or combining with other models, as SWAT model. The DNDC model will play more and more important role in future studies on global change.

Abstract:The physiological responses to hypoxic stress were studied in the common reed, Phragmites australis (Cav.) Trin. ex Steudel. Growth, leaf gas exchange, water (and ion) relations and osmotic adjustment were determined in hydroponically grown plants exposed to 10, 20 and 30 days of oxygen deficiency. The highest growth of reed seedlings was found in normoxic (aerobic) conditions. Treatment effects on biomass production were relatively consistent within each harvest. Leaf water potential and osmotic potential declined significantly as hypoxia periods increased. However, leaf turgor pressure showed a consistent pattern of increase, suggesting that reed plants adjusted their water status by osmotic adjustment in response to root hypoxia. After 20 and 30 days in the low oxygen treatment, net CO₂ assimilation and stomatal conductance were positively associated and the former variable also had a strong positive relationship with transpiration. Short-term hypoxic stress had a slight effect on the ionic status (K⁺, Ca²⁺ and Mg²⁺) of reed plants. In contrast, soluble sugar concentrations increased more under hypoxic conditions as compared to normoxia. These findings indicate that hypoxia slightly affected the physiological behavior of reed plants.

Abstract:Euptelea pleiosperma (Eupteleaceae) is a class III threatened tree species in China. Investigations on structure, regeneration and population dynamics is of great scientific significance to properly conserve, develop and use the resources of this species. This study targeted a small and isolated northernmost E. pleiosperma population in China, which is distributed in Meidigou of Taikuanhe Nature Reserve in Shanxi province. The study aimed at seeking the answers: (1) is the E. pleiosperma population growing or declining? (2) what is the implications of sprouting for the E. pleiosperma population? It is shown through this study that sprouting is a main trait of the population with 49.4% of main stems having sprouted stems. The population is growing rather than declining thanks to the outstanding sprouting trait of E. pleiosperma. The population occurs only in a small shady and moisture valley area most likely because a moist environment is necessary for E. pleiosperma to survive, develop and regenerate. Mainly by rapid producing abundant sprouted stems, E. pleiosperma forms itself as an edifying species and demonstrates strong competition ability with other coexistent canopy species in the limited area. The sprouting characteristics of E. pleiosperma provide a mechanism for the expansion and maintenance of its population.

Abstract:The pearl oyster Pinctada martensii is an important economic shellfish species and mainly cultured in the southern provinces of China. The species is cultured for marine pearl production. However, pearl quality has recently decreased because the cultured stocks had slow growth and mass mortalities caused by inbreeding depression. We have initiated a selective breeding program to improve the cultivated stocks since 2002. In 2004, a base population was developed by collecting the breeders from Beibuwan and Liushagang stocks. During the period of 2005–2007, a two successive generation selection for shell length in the base population was carried out to produce the second generation selected and unselected lines. In May of 2008, three types of lines were produced by selecting the breeders from the second generation selected and unselected lines. The three types of lines were designated as SS (Selected for three generations), SC (selected for the two generations) and CC (unselected for three generations). Realized heritability for the third generation, cumulative (over three generation) and current (for the third generation) genetic gains were evaluated by comparing the growth performance of three types of lines at days 8, 16, 45, 75, 180 and 360. It was found that the SS lines had significant larger mean shell length and shell height than the SC and CC lines at all sampling ages (P < 0.05). The realized heritability estimate for adult shell length for the third generation was 0.41, similar with those detected for the first and second generation. The cumulative and current genetic gains for adult shell length were 20.94% and 13.27%, respectively. The present results indicate that there exists a high genetic variation in the population and mass selection is potential to improve pearl oyster stocks.

Abstract:The effects of saline irrigation water and mannitol on the growth and content of essential oil, photosynthetic pigments, soluble sugars, proline, Na, macroelements (N–P–K) and microelements (Mg–Zn–Fe–Mn) of lemon balm (Melissa officinalis L.) plants were investigated. Saline irrigation water decreased certain growth characters (total leaf area, leaf number, and total fresh and dry mass). The photosynthetic pigments (chlorophylls a and b, total carotenoids) and mineral content (N–P–K–Mg–Zn–Fe–Mn) also decreased as saline irrigation water level increased. Saline irrigation water promoted the accumulation of essential oil content and its main components (citronellal, citronellol and geranyl acetate) as well as total soluble sugars, proline and Na⁺ contents. The plants treated with saline irrigation water × mannitol resulted in higher plant growth, essential oil, total soluble sugars, proline, macro and micronutrient values than those treated with saline irrigation water alone, photosynthetic pigments and Na demonstrated an opposite trend.

Abstract:To understand the effect of substrate and temperature on methane production in high frigid wetlands, soil samples along the soil profile were collected from Zoige alpine wetlands, a “hotspot” of methane emission on Qinghai-Tibetan Plateau. Our result showed that temperature had a positive influence on methane production. However, acetate accumulation was negative related with temperature. We found that supplemental methanol and acetate strongly stimulated methane production. Such result indicated that methanol and acetate are major substrates for methane production in Zoige wetlands. Moreover, we also found that methane production rates decreased with soil depths due to the decrease of available substrate in deeper soil.