How a socio-ecological system (SES) responds to changes in global environment has been deemed as a priority concern in the modern natural resources management. The resilience theory provides an important theoretic basis to scientific analysis of interactions between disturbance and adaptivity in a SES. With the contradiction between human and land resources getting increasingly prominent,, it is of great significance to analyze the connotation of resilience as a valuable feature of the nature-human system and to sum up progresses in the research of its evaluation. Based on the introduction to genesis of the resilience theory, definition of resilience was dissected and explanations of engineering resilience, ecosystem resilience and socio-ecological resilience were tried, with emphasis on analysis of their differentiation from and relationships with frangibility, adaptability and sustainability. Meanwhile, a review was presented of quantitative evaluation and application of resilience from the angle of framework, indices and tools of the evaluation. In the end, for better understanding of the resilience in SESs outlooks on the future development tendency of the resilience are described in the aspects of connotation of resilience, quantitative evaluation and remediation practice of the degraded SESs.

The "National Ecological Function Zoning"of China defined 50 national important ecological function areas, which have great significance on the protection of national and regional ecological security. Indicators were selected from two aspects of ecological stress and ecosystem structureto form ecological security evaluation system, and zoning ecological security evaluation based on remote sensing data of three periods were conducted on national important ecological function areas in order to identify areas where ecological security conditions show deterioration trends, which could provide theoretical and scientific basis for ecological security assurance of national important ecological function areas. Results show that ecological security indices of water conservation areas and biodiversity protection areas were relatively high, while soil conservation areas were in poor situation. Overall ecological security situation of national important ecological function areas has been declined. The ecological environment situation of Dongting Lake flood regulation areas and the southeastern Tibet mountain rainforest biodiversity protection areas improved significantly. While the ecological security index of the wind prevention and sand fixation areaslocated in the middle and lower reaches of Heihe River were the least and had a further declining trend.

Through expansion of the connotation of “per capita ecological carrying capacity”, the concept of ecological Load coefficient (ELC) was established. Based on multiple time sections, the ecological carrying capacity per capita of 17 cities in Anhui Province during 2001-2010 was calculated. At the same time, based on the per capita ecological carrying capacity the energy consumption, fresh water consumption, COD discharge and SO₂ emission were chosen to establish the methods for calculation and evaluation of the Gini coefficient of resources and environment (G_r,e) and the ELC in Anhui province. The results show that (1) The SO₂ emission of G_r,eare higher than the “red line” of 0.4, and the energy consumption of G_r,e is close to 0.4. The G_r,e of other items such as fresh water consumption and COD discharge are all in a relative and reasonable scope. (2) On the whole, the resource-based cities (such as Ma'anshan, Huainan), the relatively developed cities (such as Hefei) and the industrial cities along the Yangtze River (such as Anqing, Wuhu)in Anhui Province are the main factors contributing to unfairness of the resource consumption and pollutant release. These cities need to optimize the allocation of resources and environment. Cities in the mountainousareaof south Anhui Province (such as Huangshan, Chizhou, Xuancheng) are the main factors contributing to fairness of resource consumption and pollutants release. The results of thestudy can provide a theoretical basis for safety assessment and fairlydistribution of the resources and environment  of Anhui Province.

Water samples were collected along the tributaries of a drinking water source catchment for analysis in line with the procedure for risk assessment of the USEPA, and environment health risk of phthalic acid esters (PAEs) was assessed by taking into account the parameters of the region. Results show that (1) all the samples were found to have PAEs like pollutants, including Di (2-ethylhexyl) phthalate (DOP), diethyl phthalate (DEP), di-n-butyl phtalate (DBP), among which DOP was higher than the other two, displaying an order of DOP > DEP > DBP.  (2) The concentrations of DOP, DEP and DBP in the water catchment were all higher than their respective ones in other drinking water source catchments in the region and could also be sorted into the moderate or upper level of contamination in similar areas in the country and others. DOP was designated the primarily controlled contaminant of the water source catchment.(3) In areas less affected by anthrogenic disturbance, environmental health risk of pollutants in rivers was low, while in areas densely populated and concentrated with industry, the risk was high. Along a river, the risk was low in the upper reaches, high in the middle reaches and low again in the lower reaches or the reservoirs.Therefore, it can be concluded that the environment health risk of PAEs like contaminants in headwater catchment has not yet exceeded the criteria of USEPA, but among similar regions the world over, this region is moderate or high in concentration of PAEs like contaminants and does have some potential health risks. It is, therefore, essential to track potential source of PAEs in the region and take corresponding countermeasures to control the sources in environmental risk management of the region.

A case study of Jiangsu Province was conducted using questionnaires and field survey to explore status quo of the collection and utilization of rice and wheat straw of the province. Problems in collecting the straw were analyzed, taking into account meteorological data of the rice and wheat harvesting seasons in the region. Results show (1)currently the major straw utilization method is to incorporate straw directly into the field. In the two townships (A and B) investigated in the study, only 22.01% and 28.75%, separately,of the farmer households interviewed had followed the practice and both of the two townships had a considerable portion of the straw wasted or improperly disposed. In Township B over 50% of the farmer households surveyed failed to make use of any of the straw and as high as over 55% of the straw was discarded or burnt. (2) During the rice and wheat harvesting seasons, precipitation varies in the range of 7.21-87.28 mm and in every 10 days, there were1.53-5.00 rainy days. Such weather not only affectsthe timely harvesting of rice and wheat, but also seriously impedes baling, transportation, and storage of straw.(3) As the crops must be harvested in a relatively short and concentrated time period, large volumes of straw are turned out within a few days. Moreover, harvesting of the first crop often coincides with sowing of the next crop, leaving little time available for straw collection. (4) Straw collection is very low in economic benefit. A farmer can only get 60-90 RMB per day from straw collection and transportation, much lower than what they can get by working as migrant workers in city.(5) Machines designed for straw collection are rare and those now used in the operation are low in efficiency and need to be improved technically, which directly affects straw collection efficiency. The above-listed findings indicate that time shortage, negtive weather condition, low benefit and low mechanization level are the major factors affecting straw collection. To solve the problems, the following proposals are brought forth, that is, improving the economic benefit of straw collection as a driving force,accelerating development of rice and wheat sheaf-binding reaping machine,and setting up long-term operational mechanism for straw recovery, in the hope that this study may provide some useful ideas to help solve the problems.

The application of the technique of composite fingerprinting to the identification of sediment sources is based on the assumption that the type of potential sediment sources could be confirmed and the sum of the contributions of the sediment sources equals to 1. However, the uncertainty in prediction of potential sediment sources would have some impact on accuracy of the results. The upstream of the Jiuxiang River in Nanjing was investigated for case study. Mean significance tests were carried out of fingerprint factors of the sediment sources in order to test whether each predicted source could be used individually as a potential sediment source. Meanwhile, effects of different sediment sources on the accuracy of the determination based on composite fingerprinting were analyzed and compared, in an attempt to quantitatively analyze shortages in the process of sediment source prediction and explore for ways to mitigate the impact of sediment source selection on identification of sediment sources. Results show that the four predicted sediment sources were readjusted as farmland, woodland and road. The readjustment significantly enhanced  the differences in fingerprint factors between the sediment sources. The highest identification rate of 89.2% was obtained in discriminating sources by using optimum composite fingerprinting. In terms of relative contribution of sediment, the sediment sources displayed an order of farmland (39.9%~87.8%) > wood land (<0.1%~47.7%) > and road land (0~25.6%).

As an invasive plant, Bidens pilosa imposes great potential harm to agricultural production, biodiversity and safety of ecosystems. Making use of allelopathy to develop new herbicides, is a meaningful way to control and reduce negative impact of chemical herbicides to the environment. It has been reported that leaf litters of common species, such as Eucalyptus grandis, Cinnamomum camphora and Juglans regia, could generate secondary metabolites during their growing process, which show comparatively strong allelopathy to plants and microorganism, and might play an important role in the prevention of colonial invasion herbs. Selected leaf litters of E. grandis, C.camphora and J.regia,were made into different concentrations of water extracts. By combining the methods of indoor germination test and potted biological test,  indexes such as germination rate, germination speed,  aerial parts fresh weight,  antioxidant enzyme activity, and osmotic regulation substance of B. pilosa were determined. Finally, comprehensive evaluation and comparison of allelopathy effects of the three species were completed. The water extracts of E. grandis leaf litter significantly inhibited the germination rate and germination speed of B. pilosa, while C. camphora and J. regia showed weaker inhibition. The leaf litter water extracts of the three tree species promoted the activity of peroxidase (POD), superoxide dismutase (SOD) and inhibited the activity of catalase (CAT) in B. pilosa. The antioxidant enzyme system of B. pilosa treated withE.grandis leaf litter extract showed passivation response, and thus lead to obvious increase of malondialdehyde (MDA). When treated with leaf litter extracts of E. grandis and C. camphora, the soluble protein and soluble sugar in B. pilosa increased with increasing extract concentration.However, when  treated by leaf litter extracts of J. regia, the soluble protein and soluble sugar in B. pilosa showed a trend of promotion at low concentration, and inhibition at high concentration. Overall, the leaf litter of three tree species showed potential allelopathic effects on the germination and growth of B. pilosa, and led to significant changes in resistance physiological indicators in B. pilosa, but the effects varied by the tree species and the extract concentration of leaf litter. Among them, E.grandisdemonstrated the strongest inhibition on B. pilosa, followed by C.camphora, and J. regiais the weakest.