Ouyang Zhiyun

Primary evaluation of carbon sequestration potential of wetlands in China

Abstract As one of the important ecosystem services of wetlands, carbon sequestration potential of lakes and swamps in China were investigated. Significant differences were found among the carbon sequestration potential of various lakes, determined by natural conditions and human disturbance. In this study, swamps had a carbon sequestration potential of 4.90 TgC, much higher than lakes in China. Mangrove and coastal marsh have the highest carbon sediment rate among swamps. Carbon sequestration potential in returning farms to lakes and swamps was 30.26 and 0.22 GgC. … a−1, respectively. Under the ongoing national wetland conservation action plan in China, the carbon sequestration potential of wetland restoration was 6.57 GgC. … a−1. Protection and restoration measurements can improve carbon sequestration potential of wetlands.

Assessment of eco-security in the Knowledge Grid e-science environment

Ecological security is an important basis of the entire human security system, the cornerstone for human survival. Knowing the status of ecological security is crucial for making decisions to avoid ecological disaster. Existing research, both the basic research on ecological security mechanism and information service systems, is still primitive in their abilities to resolve eco-security problems. This paper investigates the eco-security impact factors and identifies eco-security types. Taking urban eco-security as an example, we develop an assessment method including the indicator system and assessment model, and construct an integrated assessment framework based on data integrity, security assessment and security management with the support of the Knowledge Grid e-science environment. The proposed assessment framework enables decision makers to better know the status of eco-security in making policies for achieving sustainability.

Application of ecological-niche factor analysis in habitat assessment of giant pandas

Abstract Ecological-niche factor analysis (ENFA) is a multivariate approach to study geographic distribution of species on a large scale with only “presence” data. It has been widely applied in many fields including wildlife management, habitat assessment and habitat prediction. In this paper, this approach was applied in habitat suitability assessment for giant pandas in Pingwu County, Sichuan Province, China. With “presence” data of giant pandas and remote sensing data, habitat suitability of pandas in this county was evaluated based on ENFA model, and spatial distribution pattern of nature reserves and conservation gaps were then evaluated. The results show that giant pandas in this county prefer high-elevation zones (> 2128 m) dominated by coniferous forest, and mixed coniferous and deciduous broadleaf forest, and avoid deciduous broadleaf forest and shrubs. Pandas avoid staying at habitats with human disturbances. Farmland is a major factor threatening panda habitat. Panda habitat is mainly distributed in north and west of Pingwu with a total area of 234033 hm2, 106345hm2 for suitable habitat and 127688 hm2 for marginally suitable habitat). 3 nature reserves were located in Pingwu, covering over 49.2% of total suitable habitat and 45.6% of total marginally suitable habitat. Although 47.2% of panda habitat was in reserves under protection, connectivity between reserves was weak and a conservation gap existed in the north part of Pingwu. Thus, a new nature reserve in Baima and Mupi should be established to link the isolated habitats.

Allergenic pollen plants and their influential factors in urban areas

Abstract Owing to unsuitable green space construction, abundant allergenic pollen plants are centralized in urban areas, producing allergenic pollen. A mass of airborne allergenic pollen could cause pollinosis to badly influence peoples robustness. To provide scientific basis for reasonable green space construction, the research advances of allergenic plants were reviewed. Firstly, species composition, phenological characteristics and influential factors (which include unsuitable green land construction, urban heat island effect, traffic pollution, etc.) were summarized. Secondly, the strategies controlling allergenic pollen plants were proposed. Thirdly, some problems on allergenic plants worthy of more research, including allergenic mechanism and methodology, were also put forward.

Comparisons of carbon storages in Cunninghamia lanceolata and Michelia macclurei plantations during a 22-year period in southern China.

Tree species composition was important for carbon storage within the same climate range. To quantify the dynamics of ecosystem carbon allocation as affected by different tree species, we measured the above- and below-ground biomass accumulation in 22 years, as well as the tissue carbon concentrations of trees in Cunninghamia lanceolata plantation and Michelia macclurei plantation. Results indicated that M. macclurei plantation significantly stored more carbon (174.8 tons/hm2) than C. lanceolata plantation (154.3 tons/hm2). Most of the carbon was found in the soil pool (57.1% in M. macclurei plantation, 55.2% in C. lanceolata plantation). Tree and soil component of M. macclurei plantation possessed significantly higher carbon storage than that of C. lanceolata plantation (p <0.05). No significant difference was found in the carbon storage of understory and forest floor. These results suggest that the broadleaved species (M. macclurei) possesses greater carbon sequestration potential than the coniferous species (C. lanceolata) in southern China.

Multichannel automated chamber system for continuous monitoring of CO2 exchange between the agro-ecosystem or soil and the atmosphere

Abstract A multichannel automated chamber system was developed for continuous monitoring of CO2 exchange at multiple points between agro-ecosystem or soil and atmosphere. This system consisted of an automated chamber subsystem with a CO2 concentration analyzer and a data logging subsystem. Both subsystems were under the control of a programmable logic controller (PLC). The automated chamber subsystem contained 18 chambers (50 cm × 50 cm × 50 cm) and a compressor. The chamber lids were closed and can be automatically opened. During measurement, one of the 18 chambers was kept closed for three minutes for measuring and the other chambers were kept open to maintain the natural soil conditions to the maximum extent. Environmental variables were simultaneously measured using sensors and recorded by the data logger. The reliability of the multichannel automated chamber system was tested and the results showed that the turbulence of the fans had no significant effect on the CO2 exchange. The changes in the air and the temperature of soil and soil moisture inside the chambers, caused by the enclosure of the chambers, were not significant. The net ecosystem CO2 exchange for the wheat ecosystem was −2.35 μmol·m−2·s−1 and the soil respiration was 3.87 μmol·m−2·s−1 in the wheat field, and 6.61 μmol·m−2·s−1 in the apple orchard.

Evaluating Conservation Effectiveness of Nature Reserves Established for Surrogate Species: Case of a Giant Panda Nature Reserve in Qinling Mountains, China

Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable. In this study, this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains, Shaanxi Province, China. The network of reserves was established mainly for the conservation of the giant panda, a species considered as a surrogate for the conservation of many other endangered species in the region. The habitat suitability of nine protected species, including the giant panda, was modeled by using Maximum Entropy (MAXENT) and their spatial congruence was analyzed. Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones (i.e., core, buffer and experimental zones). Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species, and giant panda reserves protect a relatively high proportion of the habitat of other protected species. Therefore, giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region. However, a large area of suitable habitat was excluded from the nature reserve network. In addition, four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves. It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones, thus, is being affected by human activities. To increase their conservation effectiveness, nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species. The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.

A review of beta diversity studies.

Beta diversity is an important component of biological diversity, measuring compositional change in species assemblages across temporal and spatial scales. Beta diversity concerns not only a number of ecological and evolutionary issues, but can also guide the selection of protected areas and help to optimize conservation networks. It has thus become a hot topic in biodiversity research in recent years. Researchers have used various measures and analytical methods to investigate patterns of beta diversity and its underlying mechanisms for various taxa and in different regions. Here, we reviewed literature from the past decade pertaining to the following aspects of beta diversity: metrics, temporal and spatial patterns, determinants and applications in biodiversity conservation. Whittaker introduced the term beta diversity in 1960, but defined it vaguely. As the concept of beta diversity evolved, a high variety of measures were developed to quantify the concept. The comparison of results from different studies may be hindered by the variety of measures used to quantify beta diversity. Presently, the most popular methods for measuring beta diversity are similarity/dissimilarity coefficients such as Jaccard index and Sorensen index. In the last few years, several methods to quantify beta diversity have emerged, some of which are worth noting. Beta diversity depends on temporal scale, spatial scale and taxonomic scale, and decreases with increasing analytical grain size. There is no con324 生 物 多 样 性 Biodiversity Science 第 18 卷 sensus among scientists that beta diversity decreases with latitude, i.e. that it is higher in tropics and lower near the poles. Beta diversity is high within mountain ranges and at the interface of biogeographic realms; thus, larger/more reserves are needed in these regions to cover the entire gradient of species turnover. Studies on beta diversity across temporal scales have shown that climatic change has resulted in shifts in species composition through time, and that the migration of species between different continents/regions has led to biotic homogenization. Based on a thorough review of beta diversity literature, we think the following questions might be the focus of future research: (1) the influence of evolutionary history and biological characteristics of different taxonomic groups on their beta diversity; (2) the influence of temporal/spatial scales on beta diversity and its determinants; and (3) the effect of anthropogenic activities on beta diversity.

Evaluating Value of Natural Landscapes in China

Natural landscapes consist of the natural substances, environment, and phenomena, all of which provide many benefits to people, including a sense of place, sightseeing, relaxing, and recuperating. However, the economic value of natural landscapes has only been recognized in recent decades, and the resulting large-scale decline and degradation of ecosystems now severely threatens the sustainable provision of their services to society. There is an emerging consensus that natural capital should be incorporated into the current socioeconomic accounting system. Many studies valuated natural resources at local and regional scales, but there are very few empirical studies at a national level. To provide a benchmark for natural landscape management on a national scale, we use the travel cost method (TCM) and the contingent valuation method (CVM) to determine the economic value and the spatial distribution of natural landscapes across China. Our results show that the total economic value of China′s natural landscape was 9.75 × 1011 U.S. dollars (USD) in 2012. Of this value, the highest proportion was in the eastern and southwestern regions of China, which accounts for 23.7% and 18.3%, respectively. The provinces of Guangdong, Sichuan, Yunnan, Inner Mongolia, and Heilongjiang were the top five in terms of the largest number of natural landscapes and largest economic values. Together, these five provinces accounted for 32.9% of the total number of natural landscapes and 29.4% of the total economic value in 2012. We believe this study will increase awareness of the value of natural landscapes, and more importantly provide a scientific basis for resolving conflicts between development and resource conservation.

Wetland Economic Valuation Approaches and Prospects in China

Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.