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To reveal the variation of leaf nutrient utilization strategies with altitude gradient in subtropical mountain broadleaved trees, 44 species of broadleaved trees at different altitudes (1400, 1600 and 1800 m) in Wuyi Mountains were selected to measure nutrient content, stoichiometric ratio, and nutrient resorption efficiency of green and senescent leaves, and analyzed their allometric growth relationships. The results showed that nitrogen (N) and phosphorus (P) contents in green leaves were significantly higher than those in senescent leaves, which increased with the increases of altitude. The average values of phosphorus resorption efficiency (PRE) and nitrogen resorption efficiency (NRE) were 48.3% and 34.9%, respectively. PRE was significantly higher than NRE. There was no significant difference in nutrient resorption efficiency with altitude. NRE had positive isokinetic growth with and mature leaf N content at low altitude (1400 m) and negative allometry growth with senescent leaf N content at high altitude (1800 m). PRE and N and P contents of senescent leaves had negative isokinetic growth at low altitude (1400 m) and negative allometry growth at high altitudes (1600 and 1800 m). PRE-NRE allometric growth index was 0.95 at each altitude. The nutrient contents of green and senescent leaves increased with the increases of altitude, but altitude did not affect nutrient resorption efficiency. Plants preferred to re-absorbed P from senescent leaves. Nutrient resorption efficiency of leaves at high altitude affected the nutrient status of senescent leaves.

As a new type of pollutant, microplastics accumulate continuously in the environment. The environmental problems caused by microplastics have attracted wide attention. In this study, we collected water, sediment and four types of microplastics (film, foam, fiber and fragment) from wetland in East Lake area of Poyang Lake. We used high-throughput sequencing technology to analyze the bacterial diversity and community structure of water, sediment, and microplastics surface. The results showed that the bacterial richness and diversity of water and sediment were significantly higher than that on microplastics, and the bacterial richness of foaming microplastics was significantly lower than that of the other three types of microplastics. There were significant differences of bacterial communities between water, sediment, and microplastics. There were significant differences cross different types of microplastics. Proteobacteria, Bacteroidetes, and Actinobacteria were the main bacterial communities of water, sediment, and microplastics. The relative abundance of Bacteroidetes and Actinobacteria in water was higher than that in sediments and microplastics, while the relative abundance of Bacteroidetes and Actinobacteria in foaming microplastics was higher than that in other three types. At the genus level, the dominant ones included Massilia, Flavobacteria , and Pseudomonas . The relative abundance of Massilia and Pseudomonas in water and sediments was lower than that on microplastics, and the relative abundance of Flavobacteria was not different among water, sediment and microplastics. The relative abundance of Massilia in microplastics followed an order of fragment>fiber>film>foam, and that of Pseudomonas was film>fiber>foam>fragment. The results of metabolic pathway prediction analysis showed that except for foaming microplastics, the bacterial metabolic pathways on the surface of the other three types of microplastics were significantly different from those in water and sediment. The cellular processes, organismal systems, environmental information processing, and human diseases in bacterial metabolic pathways on microplastics surface were significantly higher than those in water and sediment. Our results suggested that microbial community structure on the surface of microplastics was significantly different from that in water and sediment, and that the morphology type of microplastics affected microbial community structure on the surface.

Developing clean energy is an important strategy to achieve global carbon neutrality. In the entire life cycle industrial chain of clean energy systems, fossil energy was directly or indirectly consumed during the processes from raw material production to waste disposal stages. The energy consumed by clean energy construction differed across regions, resulting in various carbon neutrality contributions of clean energy in different regions. We used bibliometrics to sort out the energy consumption of clean energy construction in different regions, including photovoltaic power generation, wind power, hydropower, and other clean energy sources. By combining the loss of land to decrease carbon pool during the operation of clean energy, we analyzed the current research hotspots, development status and trends, and difference in carbon emissions, and summarized the carbon neutral contributions of different regions. The intensity of clean energy carbon emission in China was significantly lower than global mean value. The average intensity of carbon emission in China in the four fields of onshore wind power, offshore wind power, hydropower, and photovoltaic power was 28.8%, 18.2%, 10.1%, and 16.7% lower than global average, respectively. For further research on carbon neutrality of clean energy, it is important to establish a unified life cycle assessment system, put forward construction strategies according to geographical differences, carry out ecological benefit evaluation for clean energy, and establish a clean energy transmission network system.

The rapid urbanization adversely affects landscape pattern of mountainous cities. It is of great practical significance to explore the spatial and temporal evolution of ecological networks in mountainous areas to achieve regional ecological security. Taking Qianshan City in Anhui Province as an example, based on the land use data in 2012 and 2020, we simulated the land use situation in 2036 with PLUS model, and constructed the ecological networks in 2020 and 2036, respectively. We further analyzed its spatial and temporal evolution characteristics and explored the optimization path of ecological network. The results showed that the scale of various land use types in Qianshan City would change little from 2020 to 2036. The construction land would be centered on the built-up area, expanding in a point and block shape to the surrounding area. The ecological space would be continuously squeezed and encroached. The overall complexity and connectivity of ecological networks in Qianshan City would increase. The number and area of ecological source sites would increase, expanding spatially to the southwest and northeast. The overall density and number of ecological corridors would increase, with a lack of ecological corridor connections in the east-west direction, which need urgent improvement. The stability of ecological networks could be improved through three major measures, including protection and restoration of source sites, optimization and cultivation of corridors, and zoning control.

To improve the utilization efficiency of nutrients and water and determine the best drip irrigation frequency for long-season tomato cultivation in solar greenhouses, we cultivated tomato grafted seedlings in soil using an integrated water and fertilizer technology: drip irrigation under mulch. Seedlings drip-irrigated with balanced fertilizer (containing 20% N, 20% P 2 O 5 , and 20% K 2 O) and high-K fertilizer (containing 17% N, 8% P 2 O 5 , and 30% K 2 O) once every 12 days were set as control (CK) and that with water once every 12 days as CK 1 , while other seedling groups, drip-irrigated with a nutrient solution of Yamazaki (1978) formula for tomato, were set as treatments (T 1 -T 4 ). There were four drip-irrigation frequencies, i.e ., once every 2 days (T 1 ), 4 days (T 2 ), 6 days (T 3 ), or 12 days (T 4 ), who received the same total amounts of fertilizer and water over the 12 experimental days. The results showed that, with the decreases of drip irrigation frequency, tomato yield, the accumulation of N, P and K in plant dry matter, the fertilizer partial productivity, and the nutrient utilization rate first increased and then decreased, peaking at the T 2 treatment. Compared with CK, under the T 2 treatment, plant dry matter accumulation and the accumulation of N, P and K increased by 4.9%, 8.0%, 8.0%, 16.8%, the partial productivity of fertilizer and the utilization efficiency of water increased by 142.8% and 12.2%, the use efficiency of N, P and K was better than CK by 241.4%, 466.6% and 235.9%, respectively, and the tomato yield increased by 12.2%. Under the experimental conditions, drip irrigation with the Yamazaki nutrient solution at a frequency of 4 days could increase the tomato yield, as well as the use efficiency of nutrients and water. Under long-season cultivation, these trends would result in considerable saving of water and fertilizer. Overall, our findings provided a basis for improving the scientific management of water and fertilizers under long-season tomato cultivation in protected facilities.

The frequency of drought will increase under further warming. The increase in atmospheric CO 2 concentration, along with more frequent drought, will affect crop growth. We examined the changes of cell structure, photosynthetic physiology, antioxidant enzymes, osmotic regulatory substances, and yield of foxtail millet ( Setaria ita-lica ) leaves under different CO 2 concentrations (ambient air CO 2 concentration and ambient atmospheric CO 2 concentration + 200 μmol·mol -1 ) and water treatment (soil moisture content maintained at 45%-55%, and 70%-80% of field capacity, representing mild drought and normal water condition, respectively). The results showed that elevated CO 2 concentration increased the number of starch grains, the area of single starch grains, and the total area of starch grains in the chloroplast of millet mesophyll cells. Under mild drought condition, elevated CO 2 concentration increased net photosynthetic rate of millet leaves at the booting stage by 37.9%, but did not affect water use efficiency at this stage. Elevated CO 2 concentration increased net photosynthetic rate and water use efficiency of millet leaves under mild drought condition at the filling stage by 15.0% and 44.2%, respectively. Under mild drought condition, elevated CO 2 concentration increased the content of peroxidase (POD) and soluble sugar in millet leaves at the booting stage by 39.3% and 8.0%, respectively, but decreased proline content by 31.5%. It increased the content of POD in millet leaves at the filling stage by 26.5% but decreased the content of MDA and proline by 37.2% and 39.3%, respectively. Under mild drought condition, elevated CO 2 concentration significantly increased the number of grain spikes by 44.7% and yield by 52.3% in both years compared with normal water condition. The effect of elevated CO 2 concentration on grain yield under mild drought conditions was higher than that under normal water condition. Under mild drought conditions, elevated CO 2 concentration increased leaf thickness, vascular bundle sheath cross-sectional area, net photosynthetic rate, and water use efficiency of millet, improved the antioxidant oxidase activity, and changed the concentration of osmotic regulatory substances, alleviated the nega-tive effect of drought on foxtail millet, and finally increased the number of grains per ear and yield of foxtail millet. This study would provide a theoretical basis for millet production and sustainable agricultural development in arid areas under future climate change.

Platinum group metals (PGMs) present a variety of forms in the environment, and analysis of speciation is essential for identifying their ecological risk. Here, we reviewed the methods for the morphological analysis of three major PGMs (platinum, palladium and rhodium) in the environment, including chemical sequential extraction, hyphenated techniques for instruments, computer simulations. We outlined the types, characteristics and applications of these methods, elaborated the weaknesses, and provided prospects for future development. Among them, chemical sequential extraction is universally applied in the morphological analysis of solid-phase samples, with diverse extraction conditions and procedures proposed in the current study. However, it has not been well standardized. The hyphenated techniques for instruments have significant advantages for the determination of elemental forms in solution, of which capillary electrophoresis system can separate similar substances with the same electrophoresis ability. Liquid chromatography systems have better performance in terms of separation capacity and detection limit. The computer simulations further expand the access to morphological analysis, enabling complex morphological calculations. It was proposed to combine multiple methods in the future to continuously improve the accuracy of analytical techniques by complementing and optimizing each other.

Eddy covariance method has become a key technique to measure CH 4 flux continuously in lakes. A large number of CH 4 flux data was missing due to variable reasons. In order to reconstruct a complete time series of CH 4 flux, it is necessary to find an appropriate gap-filling method to insert the CH 4 flux data gap. Based on the routine meteorological data and CH 4 flux data measured at Bifenggang site in the eastern part of the Taihu eddy flux network during 2014 to 2017, we analyzed the control factors of CH 4 flux at the half-hour scale and daily scale. With those data, we tested that whether nonlinear regression method and two machine learning methods, random forest algorithm and error back propagation algorithm, could fill the CH 4 flux gap at the half-hour scale and daily scale. The results showed that CH 4 flux at the half-hour scale was mainly influenced by sediment temperature, friction velocity, air temperature, relative humidity, latent heat flux and water temperature at 20 cm in the growing season, and was mainly affected by relative humidity, latent heat flux, wind speed, sensible heat flux and sediment temperature in non-growing season. The CH 4 flux at the daily scale was mainly affected by latent heat flux and relative humidity. Random forest model was the best in CH 4 flux data gap filling at both time scales. The random forest model with the input variables of day of year, solar elevation angle, sediment temperature, friction velocity, air temperature, water temperature at 20 cm, relative humidity, air pressure, and wind speed was more suitable for filling the CH 4 flux data gap at the half-hour scale. The random forest model with the input variables of day of year, sediment temperature, friction velocity, air temperature, water temperature at 20 cm, relative humidity, air pressure, wind speed, and downward shortwave radiation was more suitable for filling CH 4 flux data gap at the day scale. The interpolation models could fill the data gap better at daily scale than that at the half-hour scale.

Northern peatlands are typical nitrogen-limited ecosystems, which are sensitive to global climate change and human activities. The increases of endogenous available nitrogen caused by climate warming and exogenous nitrogen input caused by human activities changed the nitrogen availability of northern peatlands, and would affect carbon and nitrogen cycling and carbon sink function of peatland. Here, we review the influence factors of carbon accumulation rate and carbon sink function in northern peatlands. The effects of nitrogen deposition, freezing and thawing, fire and other factors on nitrogen availability of northern peatlands were reviewed. The responses of plants and soil microorganisms to changes in nitrogen availability were elaborated from carbon fixation and carbon emission processes, respectively. The research related to carbon sink function of peat ecosystems under the influence of glo-bal change was prospected, aiming to help the implementation of the 'double carbon' goal.

Heat shock transcription factors (HSFs) are involved in the regulation of plant growth and development. Furthermore, HSFs regulate the expression of a series of genes related to various abiotic stress adaptations. HSFs usually form homotrimers to activate their transcriptional activity and function. Here, we review the basic structure, subcellular localization, transcriptional regulation, functional diversity of HSFs, and their roles in plant adaptation to abiotic stresses, such as extreme temperature, salinity, drought, strong light and oxidative stress, etc . HSFs are high-quality candidate genes for improving the resistance of higher plants to multiple stresses. Studies of HSFs have important application value. In the future, using HSFs to improve the resistance of various crops through genetic engineering would be prospects of development.

Cosmic-ray neutron sensing (CRNS) method was recently used to monitor soil moisture in farmland. But its spatial representation and accuracy needs further study. A field experiment was carried out to evaluate the applicability of CRNS for monitoring soil moisture in winter wheat farmland of the North China Plain. The spatial weight of CRNS detector was simulated by the ultra rapid adaptable neutron-only simulation for environmental research (URANOS) model and the CRNS-estimated soil moisture was compared with the measured soil moisture. The results showed that the CRNS detection radius obtained by URANOS simulation was 127-139 m, and that the weight distribution showed good agreement with the theoretical value. The determination coefficient ( R 2 ) and the root-mean-square error (RMSE) between CRNS-estimated soil moisture and measured soil moisture reached 0.64 and 0.05 cm 3 ·cm -3 , respectively. The CRNS-estimated soil moisture was sensitive to the changes of overall moisture in the detection area, with seasonal variation of measurement accuracy. In conclusion, cosmic-ray neutron sensing is a continuous and reliable method for monitoring total water content in winter wheat fields.

Plant functional traits is connected with vegetation adaptability to the environment. The trade-off between plant functional traits reflects resource reintegration and acquisition under grazing pressures. We summarized the differences of plant functional traits under grazing disturbance, focused on the linkages between grazing disturbance and plant functional traits. We introduced that the variation of plant functional traits resulted from the coordination between plant genetic characteristics and environmental filtration, summarized the effects of grazing on nutritional and reproductive traits, and noted that plants could use survival and reproductive strategies to adapt to the grazing disturbance. We mainly focused on the effects of grazing on plant population, community and ecosystem. The expression of plant functional traits was different under grazing disturbance. Therefore, plant functional traits could be used as indicators to explain population growth and reproduction, community assembly, and ecosystem function. In order to better serve the ecological environment of grassland with plant functional traits, reasonable grazing resis-tant species could be screened according to plant functional traits. Based on life history characteristics of grassland plant population, the scientific grazing mechanism should be formulated, and the responses of plant functional traits and resource allocation to grazing disturbance should be conducted from the perspective of individual-based level in the future.

The substitution of manure for chemical nitrogen fertilizers has great impacts on the growth of rubber seedlings and soil environment, with implications for rubber cultivation and transplantation and soil environment improvement. In this study, rubber seedlings of thermal research '7-33-97' strain were cultivated under four treatments: No fertilizer application (CK), only application of chemical fertilizer (N), manure replacing 50% chemical fertilizer (M+N), and manure replacing 100% chemical fertilizer (M). Plants parameters (including plant height, basal diameter, biomass, and chlorophyll), soil physicochemical properties (including pH, soil organic carbon and nitrogen, soil enzyme activities), and their relationships were investigated. The results showed that plant height, basal diameter, biomass, and chlorophyll content in the M+N and M treatments were significantly higher, while underground biomass and root-shoot ratio were significantly lower than those of in N treatment. Compared with CK, soil pH was significantly increased in the M treatment, decreased in the N treatment, and was not changed in the M+N treatment. Soil ammonium and nitrate content in the M+N and M treatments were significantly lower, while soil organic carbon content, the activity of β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP) were significantly higher than those of in N treatment. Results of correlation analysis showed that soil pH was negatively correlated with soil ammonium and nitrate content, but positively correlated with BG and NAG activities. The structural equation model analysis showed that soil pH had significant positive effects on seedling quality index, while nitrate content had significant negative effects, and soil enzyme activities had no significant effect. Those results indicated that soil pH and nitrate content were the important driving factors on the growth of rubber seedlings. The manure replacing of 50% and 100% chemical nitrogen fertilizer could promote rubber seedlings growth, improve soil environment, and promote sustainable development of rubber production in Danzhou City, Hainan Province.

Nutrient resorption is an important strategy of nutrient conservation, which reflecting the ability of plants to conserve and utilize nutrients and adapt to environment. To explore the relationship between nutrient content and nutrient resorption of broadleaved woody species of different life forms ( i.e ., evergreen vs. deciduous), we sampled 30 broadleaved woody species in subtropical region of China located in Yangjifeng National Nature Reserve, Jiangxi Province. The nitrogen (N) and phosphorus (P) concentrations in green and senescent leaves of each species were measured to calculate nutrient resorption efficiency. Furthermore, we analyzed the relationship of leaf nutrient concentration and resorption efficiency for the different life forms. The results showed that N and P concentrations in green leaves were significantly higher in deciduous trees than those in evergreen trees. The P concentrations of senescent leaves in deciduous woody species was significantly higher than that in evergreen woody species. There was no significant difference of N concentration in senescent leaves between evergreen and deciduous species. Nitrogen resorption efficiency (NRE) and phosphorus resorption efficiency (PRE) of the 30 broadleaved woody species were 49.6% and 50.9%, respectively. There were no significant differences between the NRE and PRE of evergreen and deciduous species. NRE and PRE negatively correlated with N and P concentrations in senescent leaves, respectively. Additionally, evergreen and deciduous species showed similar relationships between nutrient resorption efficiency and nutrient concentration in senescent leaves. The sca-ling exponent of allometric relationship between NRE and PRE was 1.18 across all the species. The nutrient resorption efficiency of all the species were affected by the nutrient status of the senesced leaves. Plants examined in this study generally re-absorbed P from senescing leaves than N.

This study aimed at understanding the differences in traits of functional twigs and leaves of a typical alpine shrub species, Rhododendron przewalskii , at Kaka Mountain in the headwater region of Minjiang River. Leaf and twig traits were compared for shrubs at different growth stages (flower bud stage and flowering stage) and altitude (3600 m and 3800 m). The effects of spatial heterogeneity on their correlations and trade-offs were evaluated at leaf and twig levels, respectively. Our results showed that twig length was significantly longer at low altitude than high altitude for the shubs at the same growth stage. The number and mass of flowers at flowering stage were significantly higher at high altitude than those at low altitude. At the same altitude, twig mass, number of leaves, total leaf mass, total leaf area and total petiole mass were all significantly greater at the flower bud stage than those at the flowering stage, while the individual leaf mass and individual petiole mass at flower bud stage were significantly smaller than those at flowering stage. Compared with the flower bud stage, the proportion of leaf mass decreased by 13% at the flowering stage, while biomass proportion of twig significantly increased. At the flower bud stage, twig mass had a higher contribution to total twig mass. In contrast, the contribution of total leaf mass to total twig mass was higher at flowering stage. More biomass of leaf was allocated to individual leaf mass at flower bud stage. More biomass of leaf was allocated to individual petiole mass and individual leaf mass at flowering stage at low altitude and high altitude, respectively. At low altitude, allometric growth patterns presented between twig mass and total leaf area, total leaf mass. Similarly, individual petiole mass and individual leaf area had allometric growth. Our results indicated that the functional traits of twigs and leaves varied across both altitude and plant growth stage.

The arid area is mainly composed of desert, with fragile eco-environment and being extremely vulnerable to the influence of natural and human perturbations. Based on the remote sen-sing ecological index (RSEI), the arid remote sensing ecological index (ARSEI) was formed to improve the remote sensing ecological index for arid area, which was coupled with the information of greenness, humidity, salinity, heat and land degradation to quantitatively evaluate the eco-environment quality. We used ARSEI and RSEI to dynamically monitor and evaluate the eco-environment quality of Ulan Buh Desert from 2000 to 2019, and analyzed their differences and their applicability in arid area. We further examined the characteristics and reasons of the temporal and spatial variations of the eco-environment quality of Ulan Buh Desert. The results showed that the ARSEI index had better applicability to the eco-environment quality in arid area than the RSEI, and it enhanced the role of land use changes in the ecological environment quality assessment. From 2000 to 2019, the overall eco-environmental quality of Ulan Buh Desert was worse. The parts under better, good, and medium grades were mainly distributed in the northern region, the parts with worse grades were mainly concentrated in the gobi and sandy land, and the poor ones were mainly located in area with low coverage vegetation. From 2000 to 2019, the overall quality of the eco-environment in the Ulan Buh Desert were becoming better. Meanwhile, the eco-environment quality of towns and farms in the northern part of the desert changed complexly, with deterioration and improvement alternately distributed. The main reason for the changes in the eco-environment of Ulan Buh Desert was the positive effects of ecological agriculture and sand industry.

To understand the contamination status of heavy metals and bacterial community in the manure and surrounding soils of cattle farm in Ningxia, we collected cattle manure at different breeding periods (lactation, calf, growing, pre-fattening and post-fattening periods) and soil samples from the largest beef breeding area in the region by different distances, with the waste land far away as control. We measured heavy metal contents and the composition and diversity of bacterial community in manure and soil samples. The results showed that: 1) The contents of Cu, Zn, Cd, Pb and Hg in cattle manure were 33.8%-95.8% lower than the national average, while As content was 94.7% higher than the national average. During the breeding periods, the change tendencies of seven kinds of heavy metals in cattle manure were different. The contents of Cu, Cd, Hg and Cr of cattle manure in the pre-fattening period were the highest across all periods. The comprehensive pollution index of heavy metals in pre-fattening and post-fattening periods of cattle manure was highest in all periods. 2) The contents of Cu and Zn in the soils with cattle manure application were higher than control, and the content of Zn were significantly higher than surrounding soil samples. All single and comprehensive soil pollution indices of soil were safe. 3) During the breeding periods, Sequence, OTU and Chao1 index of cattle manure had no specific change. Sequence, OTU and Chao1 of soil with cattle manure application were higher than the soil around the farm. 4) The types of dominant phylum were less in the manure. The relative abundance of Firmicutes was the highest, followed by Bacteroidetes and Proteobacteria. The relative abundance of Firmicutes in the growing period was significantly lower than other breeding periods, and that of other phylum had little variation among periods. The cattle farm did not affect bacterial community in the surrounding soil. The cattle manure application didn't change the relative abundance of bacteria at the phyla level. The abundance of Gp , Gemmatimona, Lysobacte, Subdivision 3 _genera_incertae_sedis were significantly higher than control and surrounding soil. 5) Organic matter, pH, EC, total nitrogen, total potas-sium, Cd and As significantly affected bacterial diversity and component abundance in cattle manure. Soil pH, total phosphorus and Hg significantly influenced soil bacterial diversity and component abundance. On the whole, the effects of physicochemical properties in cattle manure and soil on bacterial community were more significant than heavy metals. Our results could provide scientific basis for selecting the variety and dosage of feed and veterinary drugs in local cattle farms, as well as the rational application of organic fertilizers.

Clarifying the consumption of local natural capital stock and natural capital flow and its influencing factors can help alleviate the tension between the socio-economic development of the coastal zone, natural resources, and the ecological environment, and promote regional coordinated and sustainable development. Based on the two-dimensional and three-dimensional ecological footprint evaluation models, we analyzed the spatial and temporal variations of ecological footprint in the coastal zone of Zhejiang Province from 2006 to 2016, and explored the regional natural capital stock and capital flow occupancy based on footprint depth and footprint width. We analyzed the spatial and temporal heterogeneity of its influencing factors using a geographically and temporally weighted regression model. The results showed that ecological crisis in the coastal zone of Zhejiang Province deepened during the study period. The average per capita ecological deficit was 3.5 hm 2 ·cap -1 , and the per capita ecological deficit increased by 15.5%. Among them, the contribution of energy consumption account to the per capita ecological footprint was greater than that of the biological resources account. The per capita ecological footprint of each county showed an increasing trend, with significant spatial variation. The coastal zone of Zhejiang Province mainly consumed the natural capital stock, with a significant inhibitory effect on the renewal of natural capital flows. The consumption of natural capital stock was 14.87 times that of capital flow in 2016. Urban scale, economic development level, and people's income level had positive impacts on the ecological footprint of coastal counties of Zhejiang Province, while fishery production had negative effect on the ecological footprints, with transition trend to a positive one. The influence mechanism of the three factors had significant spatial and temporal differentiation.

In two growing seasons of wheat (2015-2017), we conducted a field trial with Taishan 28 in Tai'an Academy of Agricultural Science Feicheng experimental base, Tai'an City, Shandong Province. There were four irrigation levels of 150 (A 1 ), 300 (A 2 ), 450 (A 3 ), and 600 (A 4 ) m 3 ·hm -2 , and four nitrogen application levels of 90 (B 1 ), 135 (B 2 ), 180 (B 3 ), and 225 (B 4 ) kg·hm -2 . We examined the effects of the combination effects of irrigation and nitrogen on dry matter accumulation and transport, nitrogen accumulation and transport, water consumption and utilization, photosynthetic characteristics, wheat grain yield and yield components of wheat. The results showed that dry matter accumulation, nitrogen accumulation, vegetative organs production, storage and the transportation volume to grains of the dry matter and nitrogen, and dry matter and nitrogen accumulation of grain in the mature stage of wheat all reached the maximum in A 3 B 3 treatment, which were significantly different from other treatments. Under all the nitrogen treatments, soil water consumption in the 60-200 cm soil layer was A 3 >A 4 >A 2 >A 1 . Water use efficiency and nitrogen use efficiency in A 3 B 3 treatment were higher than that under A 3 B 4 , A 4 B 3 and A 4 B 4 . The net photosynthetic rate, stomatal conductance and transpiration rate of flag leaves from 7 to 28 days after flowe-ring were all significantly higher in A 3 B 3 treatment, which was conducive to the photosynthetic synthesis of carbohydrates in wheat. The interaction effect of water and nitrogen addition significantly affected grain yield and yield components. Wheat yield was the highest in A 3 B 3 treatment which reached at 9400 kg·hm -2 . In conclusion, the treatment with irrigation of 450 m 3 ·hm -2 and nitrogen of 180 kg·hm -2 could significantly improve dry matter and nitrogen accumulation, and promote transportation volume of the dry matter and nitrogen to grain. Compared with the high water and nitrogen treatment, it could effectively increase water use efficiency and nitrogen use efficiency, enhance photosynthetic capacity of flag leaf, produce more carbohydrate, and increase grain yield.

To investigate the hormone responses of Lycium barbarum to Aceria pallida infestation and the effects of exogenous salicylic acid on the infestation and development of gall mite, four phytohormones (salicylic acid (SA), jasmonic acid (JA), Auxin, and abscisic acid (ABA)) of L. barbarum leaves infested with A. pallida were determined by LC-MS/MS. Moreover, the effects of exogenous SA on the growth of gall and mite population were investigated. The results showed that contents of SA and JA in leaves infested with A. pallida were significantly higher (4.0 and 13.0 folds, respectively) than that in control, but that of Auxin and ABA did not change. The growth of gall was inhibited significantly by exogenous SA, with the inhibition increasing with the prolongation of treatment time. Meanwhile, mite population in galls treated with SA was significantly lower than that in control. Our results suggested that A. pallida could induce SA and JA resistance of L. barbarum , and that the exogenous SA could inhibit the growth of gall and mite population. Exogenous SA could be potentially used in A. pallida prevention.

Plant-derived volatiles are important for guiding herbivorous insects to their host plants. Jaapiella sp. (Diptera: Cecidomyiidae) is the most serious pest of Lycium barbarum . The young flower buds of L. barbarum are attractive to females of Jaapiella sp. for oviposition in the field. In this study, we compared response of Jaapiella sp. to volatiles from flower buds of L. barbarum at different stages, and clarified the crucial semiochemicals attracting Jaapiella sp. to lay eggs. Volatiles from young and mature flower buds were collected using SPME, and then identified and quantified by gas chromatography-mass spectrometry (GC-MS). Both electrophysiological and behavior experiments were conducted to measure the attraction of eight synthetic compounds to females and screen the crucial components based on gas chromatography-electroantennogram detection (GC-EAD) and Y-tube bioassays, respectively. Results showed that qualitative and quantitative diffe-rences between two odor profiles. Consistent electroantennographic response was observed for eight compounds from headspace collections, of which five synthetic compounds (3-carene, camphene, terpinolene, d-limonene, and (+)-pinene) were essential for significant preference or avoidance. Our results indicated that these compounds from L. barbarum flower buds could be effective candidates as oviposition attractant or repellents of Jaapiella sp., which would be helpful in the exploitation of new control agent to Jaapiella sp. in the field.

To investigate the effects of intercropped rape and film mulching on soil water content in dryland apple orchards during the low-water consumption period on the Loess Plateau, soil water content and soil water storage were measured with in situ field observations. The results showed that at the sprout period of apple trees, mean water content in 0-200 cm soil layer under apple trees with film mulching + intercropping 50% width rape (PR 1 ) and apple trees with film mulching + intercropping 100% width rape (PR 2 ) treatments increased by 7.9% and 6.9% compared with the control (apple trees without film mulching+row clearing), respectively. At the blossom period of apple trees, mean soil water content under these two treatments increased by 3.5% and 6.9%, respectively. At the sprout period of apple trees, soil water competition between apple trees and rape occurred in both PR 1 and PR 2 treatments, with the competition being most severe at the boundaries. At the sprout period, competition in the PR 1 treatment was less intense than that in the PR 2 treatment. At the blossom period, competition in the PR 1 treatment was not obvious, but the competition in the PR 2 treatment was significant. Moreover, at the sprout and blossom period, a low-soil-water-content zone was observed in the PR 2 treatment. Compared with the control, both PR 1 and PR 2 treatments increased soil water storage in 0-80 cm layer, and soil water was not deficit in the 0-200 cm layer. In conclusion, the implementation of PR 1 model is conducive to improve soil water availability in the dryland apple orchard on the Loess Plateau during the low-water consumption period.

We estimated grassland NPP using CASA model in the Loess Plateau during 2000-2015 and further analyzed the spatiotemporal dynamics, stability and persistence of grassland NPP. The driving factors of grassland NPP were analyzed from four aspects, i.e., vegetation types, topographic factors, climate change, and human activities. The results showed that the average NPP was 202.93 g C·m -2 ·a -1 . The grassland NPP showed an increasing trend with an average increase rate of 2.43 g C·m -2 ·a -1 . The distribution of NPP in grassland had obvious spatial heterogeneity, which was generally high in the south and low in the north. 91.2% of the total grassland area showed an increasing trend, mainly distributed in most areas of Shaanxi Province, Longdong and Longzhong areas of Gansu Province, and most parts of Qinghai Province. The regions with a stable growth condition of grassland NPP mainly located in the south of Ordos, northern Shaanxi, and Gansu. The future change trend of grassland NPP would be consistent with that of the past in most areas. The grassland NPP would continue to increase in most areas of Shaanxi Province, Longzhong and Longdong areas in Gansu Province. The average NPP of slope grassland was 703.37 g C·m -2 ·a -1 , while that of alpine and subalpine grassland was 57.28 g C·m -2 ·a -1 . The grassland NPP was higher in high altitude area and relative low in plain and hilly area. The increased precipitation promoted the increase of grassland NPP during the study period. Human activities such as improvement of overgrazing and returning cropland to grassland also played an important role in the increase of grassland NPP in the Loess Plateau.

The continuous urbanization leads to increasing pressure on the ecological environment. It is a key point to measure regional ecological environment quality objectively, accurately and quickly from multiple directions in ecological research. In this study, the normalized vegetation index (NDVI), wet index (WET), land surface temperature (LST), and normalized difference building-soil index (NDBSI) were extracted from the aspects of greenness, humidity, heat and dryness. The ecological quality of Xiongan New Area between 1995 and 2015 was evaluated by integrating selected indicators to measure the remote sensing ecological index (RSEI) with principal component analysis technology based on ENVI platform. The results showed that the average RSEI of Xiongan New Area was 0.724, 0.710, and 0.682 in 1995, 2004 and 2015, respectively, showing a downward trend. RSEI mainly changed from 4, 5 to 1, 2 and 3 in the study area from 1995 to 2015. Ecological quality improved and deteriorated area accounted for 8.9% and 20.9% of the total area respectively. The ecological quality improved area was mainly located in the east and south of Xiongxian County, because a large area of forests and gardens was highly valued and strictly protected by the local government. The ecological quality deteriorated area was in the periphery of the town and the surrounding area of Baiyangdian due to the sharp decline of the water area of Baiyangdian and the continuous urbanization. The three-year average correlation coefficient between RSEI and each component index was 0.804, which was higher than that between other component indices. Our results showed that RSEI could efficiently integrate the information of each component index and comprehensively and accurately reflect the ecological quality of the study area.

Under the positive human land use regulation (e.g. afforestation), understanding the impacts of landscape pattern changes on urban and rural thermal fields can provide reference data for future construction and optimization of urban afforestation projects and bring new insights for future landscape patterns and thermal fields environment related research. Under the context of "One Million Mu Plain Afforestation Project" in Beijing plain area, we applied remote sensing technology and geographic information system and used transfer-matrix method and coupling analysis to evaluate the impacts of plain afforestation on thermal field environment and to explore the correlation between changes in landscape patterns resulted from urban afforestation projects and urban land surface temperature. Our results showed that the percentage of landscape (PLAND) of forests and parks increased by 7.6% and 0.5% after the afforestation project in Beijing plain area, respectively. The heat island intensity decreased by 19.2% of entire plain area, and by 23.3% of suburban area, however, it increased by 23.5% of city area. Spanning urban to urban-rural interface, the PLAND of forests and parks, the mean patch size (MPS) of forests and wetlands were significantly negatively correlated with the changes in landscape surface temperature (LST). In city area, the area-weighted mean shape index (AWMSI) of forests was significantly positively correlated with the changes of LST. In suburban area, the MPS and AWMSI of forests showed significantly negative correlation with changes of LST, which was contrary to parks. After the implementation of afforestation project in Beijing plain area, the increased urban forests and urban parks had mitigated thermal fields to some extent. The scale of mitigation was limited and most areas with decreased heat island intensity were concentrated in newly planted sites in suburban area. The more connected the forests and wetlands, the better the relief of the thermal fields in the plain area. Impacted by the grain size, time, topography, human activities and other factors, the change in landscape patterns caused by the control of land use structure showed non-linear correlation with the change of LST.

Conservation tillage is one of the most important agricultural management measures on soil water conservation and crop yield increments. Based on long-term experiment during 2011 to 2016, effects of different tillage treatments, including conventional tillage, no-tillage and subsoiling treatments, on soil water condition, crop yield and water use efficiency were analyzed. The results showed that the average and relative soil water conservation rate was 7.3% and -0.68% at jointing stage of winter wheat under no tillage and subsoiling treatments, respectively. Compared with conventional tillage, soil water storage significantly increased in 0-60 cm soil layer at jointing stage of winter wheat under no-tillage. Besides, the mean values of soil water content significantly increased in 0-100 cm soil layer at jointing, flowering, filling, and harvesting stages under no tillage treatment while that was not significantly increased at jointing stage under subsoiling treatment. Furthmore, no-tillage treatment significantly increased the yield and water use efficiency of winter wheat, especially in the dry years. Therefore, soil moisture conservation ability and yield increment of no tillage was better than that of the subsoiling treatment in dry years.

To investigate the influences of sewage and cadmium combined stress on maize seedling metabolites, we took GC-MS metabonomics technology to analyze the metabolite species, content and metabolic pathways. A total of 50 kinds of metabolites were identified. Under single stress of Cd, the malic acid content in maize seedling decreased, the citric acid content increased significantly, and the tricarboxylic acid cycle was relatively stable. Under the combined stress, both malic acid and citric acid contents increased significantly, and the tricarboxylic acid cycle was inhibited. Both single Cd stress and combined stress of sewage and Cd, especially the latter, led to the decrease of glucose and the increase of those substances related to resistance, such as proline, putrescine, muscle and γ-aminobutyric acid, which indicated the photosynthesis was inhibited. It was concluded that sewage and cadmium combined stress influence on maize seedling metabolites mainly by inhibiting the tricarboxylic acid cycle and photosynthesis.

In order to study the effects of salicylic acid on the growth and physiological performance of Ulva prolifera with different proliferative styles, we took U. prolifera from vegetative (VU) and spore proliferative cells (SU) as materials, and cultured them under different salicylic acid concentrations to investigate their growth rate, chlorophyll fluorescence, SOD and soluble protein content. The results showed that the growth of both VU and SU was promoted by low concentration of salicy-lic acid, especially for VU. Under 0.2 Μg·mL -1 salicylic acid treatment, VU showed the highest relative growth rate of 21.0%, and the maximum photochemical efficiency (F v /F m ) increased by 9.8% compared with SU. Additionally, salicylic acid affected the SOD activity significantly, and the enzyme activity of VU increased by 52.0% and 198.6% under 0.2 and 0.5 Μg·mL - 1 salicylic acid treatment, and that of SU increased by 54.1% and 38.0%, respectively. Salicylic acid also promoted the relative electron transfer rate (rETR), photosynthesis and protein content of both VU and SU. In conclusion, salicylic acid benefited the growth of two kinds of U. prolifera, especially for VU.

To study the combined effects of exogenous salicylic acid (SA) and ultraviolet radiation (UV) on marine green algae Ulva prolifera under high (160 Μmol·m -2 ·s -1 ) and low (70 Μmol·m -2 ·s -1 ) light intensities, the growth, chlorophyll fluorescence parameters, photosynthetic rate of oxygen, superoxide dismutase (SOD) activity, soluble polysaccharide and soluble protein contents were investigated after they grew with or without ultraviolet (UV, 3.2 W·m -2 ) radiation in the presence or absence of SA (10 Μg·mL -1 ) for three days. The treatments included control group (CK), SA, UV and UV+SA treatments. Results showed that under the low light intensity without UV condition, the relative growth rate was enhanced, Chl a and soluble protein contents were decreased by SA. Under the high light intensity without UV condition, the relative growth rate was decreased, Chl a content, respiratory rate, photosynthetic rate of oxygen, soluble polysaccharide and soluble protein contents were enhanced by SA. Under the high light intensity with UV condition, the relative growth rate, Chl a and soluble polysaccharide contents were enhanced by UV+SA. Additionally, under the low light intensity with UV condition, compared to UV treatment, the maximum photochemical efficiency (F v /F m ) and soluble protein contents were respectively increased by 139.8% and 32.2% under the UV+SA treatment. In conclusion, SA reduced the inhibitory effects of U. prolifera induced by UV, and the effects were more significant under the high light intensity.

In this study, we explored the effects of cadmium (Cd) on mouse sperm motility parame-ters, protein tyrosine phosphorylation and the location of tyrosine-phosphorylated targets using computer-assisted sperm analysis (CASA), western blot (WB) and immunofluorescence technique coupled to sperm in vitro culture method, respectively. The results showed sperm motility was inhibi-ted by Cd in a dose-dependent manner and when Cd increased to 1.0 μmol·L -1 , sperm motility was inhibited significantly (P<0.05). Simultaneously, protein tyrosine phosphorylation was enhanced by Cd and in particular, the tyrosine phosphorylation of ～55 kDa proteins was greatly promoted when Cd concentrations were greater or equal to 1.0 μmol·L -1 (P<0.05). Importantly, these tyrosine-phosphorylated proteins were mainly localized in the middle piece of mouse sperm. However, when sperm was incubated with 30 μmol·L -1 ethylene glycol tetraacetic acid (EGTA) and 10 μmol·L -1 Cd concurrently, both the tyrosine phosphorylation of ～55 kDa proteins and sperm motility were not changed obviously (P>0.05). These results suggested that Cd may inhibit sperm motility by inducing the tyrosine phosphorylation of ～55 kDa proteins in the middle piece and EGTA could chelate Cd ions to relieve its toxicity. This study demonstrated that Cd induced the tyrosine phosphorylation of a specific subset of proteins and thus decreased sperm motility. Interes-tingly, EGTA acted as an inhibitor to block Cd from entering the sperm, which provided a novel research method for revealing the molecular mechanisms of reproductive toxicity caused by Cd.

Spiny head croaker (Collichthy lucidus) is an important bottom fish distributing from the East China Sea to the Yellow Sea. In order to investigate the seasonal variation in diet composition and feeding habits, a total of 270 specimens were collected in the Yangtze Estuary from November, 2013 to August, 2014, and analyzed by using the stomach contents analysis method. The importance of different prey items was evaluated by the frequency of occurrence, abundance and mass followed by using these data to calculate the index of relative importance (IRI) and the index of preponderance (Ip) for each taxonomic category. The results showed that the diet of C. lucidus consisted of 30 species belonging to 8 orders, in which shrimps, with 38.5 IRI% and 79.1 Ip values, was the most important prey species. The followings were Mysidacea and Amphipoda. The dominant species in the diet of C. lucidus were Palaemon gravieri, Exopalaemon annandalei, E. carinicauda, Acanthomysis longirostris, A. brevirostris, Synidotea laevidorsalis and Calanus sinicus. The dominant species in the diet varied in different seasons. P. gravieri, E. annandalei and A. brevirostris were dominant species in spring and summer, A. longirostris, A. brevirostris and E. carinicauda in autumn, and P. gravieri, C. sinicus and Pesudeuphausia sinica in winter. There was 10.4% of total samples with empty stomachs, and the highest percent appeared in winter, and the lowest in autumn. The mean stomach fullness index of the whole samples was 0.6%, with the highest found in spring, the lowest in winter, indicating the feeding activity of C. lucidus varied significantly among seasons.

In order to assess the resource status of Collichthys lucidus in coastal waters of Yangtze estuary, the growth and population parameters were studied by the length frequency distribution method based on the bottom trawl investigation data from 2012 to 2013. Von Bertalanffy growth parameters were calculated by using the ELEFAN module in FiSAT II software while the natural mortality rate (M) was estimated via Pauly's empirical equation. Besides, the Beverton-Holt dynamic model was developed to predict the variation trend of C. lucidus resource in coastal waters of Yangtze estuary. The results showed that in 2012-2013, a total of 4201 samples of C. lucidus with body lengths ranging from 18 to 155 mm were collected from the coastal waters of Yangtze estuary. The growth parameter (K) and limit length (L.) were 1.1 and 162.75 mm while the total mortality rate (Z), the natural mortality rate (M) and the fishing mortality rate (F) were 4.040, 1.683 and 2.357, respectively. Moreover, the current exploitation (E) of C. lucidus in coastal waters of Yangtze estuary was 0.583 per year, which was larger than Fopt (0.5). Corresponding to the average stock of 576.02 t, the resource amount of C. lucidus reached up to 1.33 x 10(8) individuals. These indicated that C. lucidus has been overfished in Yangtze estuary area.

Culturable endophytic bacteria were isolated from medicinal plant Ilex cornuta by plate-spreading method, strains with strong inhibitory effect on phytopathogen were screened by confrontation culture and fermentation filtrate culture methods, and the morphological changes of phytopathogen hyphae treated with endophytic bacteria were examined by microscopy and micrograph. Their phylogenetic relationships were determined by homology analysis of the 16S rDNA sequences of PCR products and the taxonomic status of the selected strains was determined based on their morphology, physiology, biochemical test results and 16S rDNA sequence analysis. A total of 85 endophytic bacteria were isolated from the healthy roots, stems, leaves and fruits of I. cornuta, and 10 strains of them showed strong inhibitory effect on Alternaria alternata, Magnaporthe grisea, Fusarium oxysporum, and were preliminarily identified belonging to four genera and seven species. Three strains with the strongest inhibitory effect, GG78 (60.3%), GG31 (48.1%) and GG13 (61.0%) belonged to Enterobacter cloacae, Enterobacter ludwigii and Bacillus cereus, respectively. Microscopic analyses showed that the inhibited phytopathogen hyphae became deformed, distorted, and partially expanded forming plasma concentration and hair-like branch on the hyphae base. These morphological changes could be caused by the extracellular metabolic substances secreted by the endophytic bacteria, such as antibiotics, hydrolytic enzymes, alkaloids and so on.

The reservoirs distributed in the western part of Haihe River basin play a key role in drinking water supply in the densely populated region. The potential ecological risk of heavy metals stored in the reservoir sediments has drawn more attention during recent decades. In this study, a total of 10 reservoirs in the western Haihe River basin were sampled. The sediment samples were assessed by the Hakanson potential ecological risk evaluation index. The sediments of upstream and downstream rivers were also sampled for comparative analysis with those of the reservoirs. The results indicated the concentration of Cd was significantly higher than the background value in this region, it was 1.67 times of the background value on average and the highest was 2.77 times. The concentration of Pb was higher than the background value for more than half of the reservoirs. The potential ecological risk was evaluated by the toxic coefficient. The ecological risk level was decreased in the order of Cd>As>Pb>Ni>Cu>Cr>Zn. The ecological risk of Cd in most reservoir sediments belonged to a moderate harm. Xidayang Reservior, which supplied the drinking water for Beijing and Baoding, had the highest level of Cd pollution. The ecological risk of Cd in the upstream and downstream rivers was significantly higher than that of the reservoirs. In addition, the ecological risks of Pb, Cu and Ni in the upstream rivers were also higher than the reservoirs. The difference of ecological risks of Zn and Cr was not significant between reservoirs and rivers.

Today, the main threats for Sciurus vulgaris are illegal hunting, deforestation, and subsequent population fragmentation, combined with interspecific competition from S. carolinensis in some regions of Europe, which has led to a sharp reduction in the number of population. S. vulgaris has been listed as Near Threatened IUCN Red List and included in key protected wild animals in Jilin Province, China. The molecular ecology of S. vulgaris is developing rapidly with the rapid development of molecular biology methods. In particular, the research of mtDNA fragments and the application squirrel study microsatellite loci has further promoted the molecular ecology of S. vulgaris. In this study, the molecular phylogeny, the genetic diversity and the molecular phylogeography involving the molecular ecology of S. vulgaris were reviewed. Four areas for the future development in molecular ecology of S. vulgaris were proposed: 1) to further explore the molecular phylogeny relationship between S. vulgaris and S. lis; 2) the comparative analysis of the genetic diversity of S. vulgaris for continuous populations, isolated populations and metapopulation; 3) the analysis of molecular phylogeography of S. vulgaris based on other markers of nuclear; 4) to explore whether there existed the quaternary glacial refuge in Asia.

To evaluate the choice preference of fish habitat in the Yangtze estuary, juvenile Collichthys lucidus which is the dominant species in spring was selected. The 4 indicator factors, including abundance of Pseudograpsus albus, salinity, substrate type and water depth, were selected from 19 environmental factors. Then, the indices of the habitat suitability curves of the 4 indicator factors were established, and the HSI of juvenile C. lucidus at each site was calculated. The results indicated that HSI was almost more than 0.5 in North Branch, and less than 0.2 in South Branch. It showed that the North Branch of Yangtze estuary was the main nursery area of C. lucidus. The most suitable growth sector was the area with salinity more than 14, mean grain size of substrate less than 29 μm and water depth 2 to 5 m, which was consistent with the distribution of HSI. The study demonstrated that biological factors could be characterized by the response of juvenile C. lucidus to the environment. Chemical oxygen demand, ammonium nitrogen, total phosphorus and volatile phenol did not have significant correlation with the fish abundance, with which nitrite nitrogen, nitrate nitrogen and total nitrogen had significant positive correlation. It suggested that the eutrophication of the survey area had not damaged the habitat of C. lucidus. However, copper ion and cadmium ion had significant negative correlation with the fish abundance, which indicated that the heavy metal pollution had harmed the growth and distribution of juvenile C. lucidus. It was inferred that the heavy metal pollution was the restrictive factor influencing the fish habitat in Yangtze estuary.

Landscape connectivity is an important indicator to measure effectiveness of landscape ecological services. Waterbody connectivity in Lianyun New City, the new reclamation region of Lianyungang, was investigated based on GIS technology and effective distance model. The results showed that the total connectivity of waterbodies was poor in Lanyun New City. Connectivity of patches was related to characteristics of ecological process, ecological services value and spatial arrangement. The higher the ecosystem services value of patches was, the greater its contribution to the overall water landscape connectivity was. Some patches with long strip structure played a key role to improve the landscape connectivity. By classifying the importance of connectivity and functional groups of waterbody patches, planning of waterbodies in Lianyun New City conformed to the theory of non-substitutable pattern developed by Forman. Waterbody patches with corresponding functions should be considered with priority when planning and building a new city. The present study demonstrated that connectivity of patches should be an important factor to be considered in ecological landscape planning. Construction of ecological corridors should not only take the number of ecological landscapes into consideration, but also pay attention to spatial arrangement of landscapes in order to improve the overall landscape connectivity.

Mongolian oak (Quercus mongolica) is an important constructive and accompanying species in mixed broadleaf-conifer forest in Northeast China, In this paper, a laboratory burning experiment was conducted under zero-slope and no-wind conditions to study the effects of fuel moisture content, loading, and thickness on the fireline intensity, fuel consumption, and combustion efficiency of the Mongolian oak leaf litter fuelbed. The fuel moisture content, loading, and thickness all had significant effects on the three fire behavior indices, and there existed interactions between these three affecting factors. Among the known models, the Byram model could be suitable for the prediction of local leaf litter fire intensity only after re-parameterization. The re-estimated alpha and beta parameters of the re-parameterized Byram model were 98.009 and 1.099, with an adjusted determination coefficient of 0.745, the rooted mean square error (RMSE) of 8.676 kW x m(-1), and the mean relative error (MRE) of 21%, respectively (R2 = 0.745). The re-estimated a and b by the burning efficiency method proposed by Albini were 0.069 and 0.169, and the re-estimated values were all higher than 93%, being mostly overestimated. The Consume model had a stronger suitability for the fuel. The R2 of the general linear models established for fireline intensity, fuel consumption, and burning efficiency was 0.82, 0.73 and 0.53, and the RMSE was 8.266 kW x m(-1) 0.081 kg x m(-2), and 0.203, respectively. In low intensity surface fires, the fine fuels could not be completely consumed, and thus, to consider the leaf litter and fine fuel in some forest ecosystems being completely consumed would overestimate the carbon release from forest fires.

Soil salinization is one of the most important eco-environment problems in arid area, which can not only induce land degradation, inhibit vegetation growth, but also impede regional agricultural production. To accurately and quickly obtain the information of regional saline soils by using remote sensing data is critical to monitor soil salinization and prevent its further development. Taking the Weigan-Kuqa River Delta Oasis in the northern Tarim River Basin of Xinjiang as test object, and based on the remote sensing data from Landsat-TM images of April 15, 2011 and September 22, 2011, in combining with the measured data from field survey, this paper extracted the characteristic variables modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), and the third principal component from K-L transformation (K-L-3). The decision tree method was adopted to establish the extraction models of soil salinization in the two key seasons (dry and wet seasons) of the study area, and the classification maps of soil salinization in the two seasons were drawn. The results showed that the decision tree method had a higher discrimination precision, being 87.2% in dry season and 85.3% in wet season, which was able to be used for effectively monitoring the dynamics of soil salinization and its spatial distribution, and to provide scientific basis for the comprehensive management of saline soils in arid area and the rational utilization of oasis land resources.

Lightning-caused fire is the most important natural fire source. Its induced forest fire brings enormous losses to human beings and ecological environment. Many countries have paid great attention to the prediction of lightning-caused fire. From the viewpoint of the main factors affecting the formation of lightning-caused fire, this paper emphatically analyzed the effects and action mechanisms of cloud-to-ground lightning, fuel, meteorology, and terrain on the formation and development process of lightning-caused fire, and, on the basis of this, summarized and reviewed the logistic model, K-function, and other mathematical methods widely used in prediction research of lightning-caused fire. The prediction methods and processes of lightning-caused fire in America and Canada were also introduced. The insufficiencies and their possible solutions for the present researches as well as the directions of further studies were proposed, aimed to provide necessary theoretical basis and literature reference for the prediction of lightning-caused fire in China.

A field survey was conducted in the Quercus wutaishanica shrubs in Liupan Mountains of Ningxia, Northwest China to study the predation and removal of rodents on the seeds of Q. wutaishanica, Prunus salicina and Pinus armandii, aimed to explore the effects of seed size and pericarp traits on the predation and removal behaviors of rodents. The in situ seed predation rates of smaller Q. wutaishanica seeds and P. armandii seeds were significantly higher than those of larger Q. wutaishanica seeds and P. salicina seeds. The P. salicina seeds with hard and thick pericarp (endocarp) had the highest predation rate and hoarding rate after the removal by rodents. The movement distance of larger Q. wutaishanica seeds during predation events was the longest (3.10 m), and the seed hoarding distance of this species (6.48 m) was significantly longer than that of the three other types of seeds. Over 80% of sites were used as the predation sites by rodents for the seeds, except that the P. salicina seeds contained only a single seed and the cache sites contained a single seed accounted for over 90% for all types of seeds. Few predation and cache sites containing over two seeds were detected. Higher proportion of P. armandii seeds were predated in microhabitats except at the base of shrubs and in the holes after removal by rodent, while the seeds of other three types were predated mainly at the base of shrubs and in the holes after removal by rodents. The seed hoarding patterns after removal by rodents were primarily determined by pericarp traits, and higher proportion of soil burial that the rodents hoarded seeds with hard pericarp (endocarp) was detected.

A comparative study was made on the nutrient content in rhizosphere soil and the microflora in rhizosphere soil and on rhizoplane of healthy and red-leaf diseased Salvia miltiorrhiza plants, aimed to approach the microecological mechanisms of red-leaf disease occurrence in S. miltiorrhiza. The N, P, K, and Mn contents in the diseased plant leaves were significantly lower than those in the healthy plant leaves (P < 0.05). No significant difference was observed in the available P content in the rhizosphere soils of diseased and healthy S. miltiorrhiza, but the available N and K contents were significantly higher (P < 0.05) in the rhizosphere soil of diseased S. miltiorrhiza. These results indicated that the red-leaf disease occurrence in S. miltiorrhiza was related to plant P deficiency, but the lack of P in the plants was not caused by the insufficient soil P supply. As compared with those in healthy S. miltiorrhiza rhizosphere, the bacterial number in diseased S. miltiorrhiza rhizosphere soil decreased by 41.3% , while the fungal and actinomycetes numbers increased by 156.6% and 189.5% (P < 0.05), respectively. Similar variations in the numbers of bacteria, fungi, and actinomycetes were observed on diseased S. miltiorrhiza rhizoplane. In the rhizosphere soil and on the rhizoplane of diseased S. miltiorrhiza, the predominant microbial species that might be harmful included six fungi (Fusarium solani, Myrothecium roridum, F. tricinctum, Aspergillus calidoustus, F. oxysporum, and Dothideomycetes sp.), four actinomycetes (Streptomyces lateritius, Lentzea waywayandensis, S. stelliscabiei and S. collinus), and two bacteria (Bacillus aryabhattai and Piscinibacter aquaticus). These predominant soil microbes likely caused plant P deficiency via negatively affecting the growth of roots and their absorption of soil nutrients. It was suggested that the red-leaf disease occurrence in S. miltiorrhiza was closely related to the plant P deficiency caused by the abnormality of soil microflora in the rhizosphere soil and on the rhizoplane of S. miltiorrhiza.

A field survey with random block design was conducted to study the effects of different landscape patch structure on the arthropod community in tea plantations. In the tea plantations with small woodland (QM) or Acacia confuse (XS) patches, predatory spider had the highest proportion, occupying 62.3% and 69.5% of the total arthropods, respectively, being significantly higher than that in the tea plantations close to paddy field (DT) or near a village (RJ). The tea plantations with QM had the highest diversity index and species richness of arthropod community, while the evenness index and dominance index were not significantly different from the other tea plantations. The tea plantations with QM and XS had much richer natural enemies, and the order of the diversity index, evenness index, and richness index of natural enemies in the tea plantations ranked as QM > XS > DT > RJ. It was suggested that landscape patch structure had great effect on the diversity of arthropod community in tea plantations.

Taking fuel moisture content, fuel loading, and fuel bed depth as controlling factors, the fuel beds of Mongolian oak leaves in Maoershan region of Northeast China in field were simulated, and a total of one hundred experimental burnings under no-wind and zero-slope conditions were conducted in laboratory, with the effects of the fuel moisture content, fuel loading, and fuel bed depth on the flame length and its residence time analyzed and the multivariate linear prediction models constructed. The results indicated that fuel moisture content had a significant negative liner correlation with flame length, but less correlation with flame residence time. Both the fuel loading and the fuel bed depth were significantly positively correlated with flame length and its residence time. The interactions of fuel bed depth with fuel moisture content and fuel loading had significant effects on the flame length, while the interactions of fuel moisture content with fuel loading and fuel bed depth affected the flame residence time significantly. The prediction model of flame length had better prediction effect, which could explain 83.3% of variance, with a mean absolute error of 7.8 cm and a mean relative error of 16.2%, while the prediction model of flame residence time was not good enough, which could only explain 54% of variance, with a mean absolute error of 9.2 s and a mean relative error of 18.6%.

To investigate the effects of temperature on the population growth of Therioaphis trifolii (Monell) (Homoptera: Aphididae), a laboratory experiment was conducted to study the development, reproduction, and life table of the spotted alfalfa aphid at nine constant temperatures ranged from 15 to 35 degrees C. The aphid could not survive at 35 degrees C. The total nymphal period shortened significantly with increasing temperature. From birth to adult stage, it required 18.33 days at 15 degrees C, but only 4.02 days at 32 degrees C. The survivorship of the nymphs ranged from 40.0% (32 degrees C) to 83.6% (25 degrees C). The average longevity of the adults ranged from 10.64 days at 32 degrees C to 20.87 days at 23 degrees C. The reproductive peak was advanced with increasing temperature, and the reproduction duration at all test temperatures was 3-6 days except that at 15 degrees C (15 days). The average fecundity and the highest fecundity were the highest at 25 degrees C, being 82.0 and 149.0 offspring per female aphid, respectively. When the temperature increased, the mean generation time was gradually decreased from 31.17 days at 15 degrees C to 10.17 days at 32 degrees C. The net reproductive rate was the highest (68.62) at 25 degrees C and the lowest (13.96) at 32 degrees C. The intrinsic rate of increase was 0.10-0.30 per day, with the highest at 28 degrees C but the lowest at 15 degrees C. The developmental threshold temperature and thermal constant of the nymphs were 9.35 degrees C and 97.83 day-degrees, respectively. Unary quadratic equation could be used to describe the relationships of the fecundity, net reproductive rate, and intrinsic growth rate with the temperature.

A laboratory burning experiment was conducted to measure the fire spread speed, residual time, reaction intensity, fireline intensity, and flame length of the ground surface fuels collected from a Korean pine (Pinus koraiensis) and Mongolian oak (Quercus mongolica) mixed stand in Maoer Mountains of Northeast China under the conditions of no wind, zero slope, and different moisture content, load, and mixture ratio of the fuels. The results measured were compared with those predicted by the extended Rothermel model to test the performance of the model, especially for the effects of two different weighting methods on the fire behavior modeling of the mixed fuels. With the prediction of the model, the mean absolute errors of the fire spread speed and reaction intensity of the fuels were 0.04 m X min(-1) and 77 kW X m(-2), their mean relative errors were 16% and 22%, while the mean absolute errors of residual time, fireline intensity and flame length were 15.5 s, 17.3 kW X m(-1), and 9.7 cm, and their mean relative errors were 55.5%, 48.7%, and 24%, respectively, indicating that the predicted values of residual time, fireline intensity, and flame length were lower than the observed ones. These errors could be regarded as the lower limits for the application of the extended Rothermel model in predicting the fire behavior of similar fuel types, and provide valuable information for using the model to predict the fire behavior under the similar field conditions. As a whole, the two different weighting methods did not show significant difference in predicting the fire behavior of the mixed fuels by extended Rothermel model. When the proportion of Korean pine fuels was lower, the predicted values of spread speed and reaction intensity obtained by surface area weighting method and those of fireline intensity and flame length obtained by load weighting method were higher; when the proportion of Korean pine needles was higher, the contrary results were obtained.

Aimed to understand the fire behavior of Mongolian oak leaves fuel-bed under field condition, the leaves of a secondary Mongolian oak forest in Northeast Forestry University experimental forest farm were collected and brought into laboratory to construct fuel-beds with varied loading, height, and moisture content, and a total of 100 experimental fires were burned under no-wind and zero-slope conditions. It was observed that the fire spread rate of the fuel-beds was less than 0.5 m x min(-1). Fuel-bed loading, height, and moisture contents all had significant effects on the fire spread rate. The effect of fuel-bed moisture content on the fire spread had no significant correlations with fuel-bed loading and height, but the effect of fuel-bed height was related to the fuel-bed loading. The packing ratio of fuel-beds had less effect on the fire spread rate. Taking the fuel-bed loading, height, and moisture content as predictive variables, a prediction model for the fire spread rate of Mongolian oak leaves fuel-bed was established, which could explain 83% of the variance of the fire spread rate, with a mean absolute error 0.04 m x min(-1) and a mean relative error less than 17%.

Participatory appraisal method was adopted to investigate the recent livelihood status of different type farmers and herdsmen's households in the Taipusi Banner of Inner Mongolia agriculture- animal husbandry ecotone, aimed to understand their livelihood strategies and restricting factors and to search for the ways to improve their living standards. The households dealing with pure agricultural production had smaller family size, with older age-structure and lower educational level, and their simple livelihood strategies brought about larger vulnerability and risk. To introduce and expand non-agricultural activities would be the important way to promote the livelihood diversification and to reduce the livelihood risks of these households. The households dealing with pure animal husbandry took grazing as the main subsistence, and their production activities were greatly restrained by the pasture vulnerability. To develop environment-friendly and high-yielding agriculture and animal husbandry would be the effective way to solve the livelihood problems of these households and to protect the ecological environment. The households dealing with both agricultural production and business or dealing with both animal husbandry and business generally had larger family size, with younger age- structure, higher diversity in labor division, larger proportion of non-farming activities, and better living standards. Especially for the households dealing with both animal husbandry and business, their income was much higher.

This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability.

Based on the daily meteorological data from 72 weather stations from 1961-2003, a quantitative analysis was conducted on the spatiotemporal changes of the potential evapotranspiration in the Plain. The Penman-Monteith model was applied to calculate the potential evapotranspiration; the Mann-Kendall test, accumulative departure curve, and climatic change rate were adopted to analyze the change trend of the evapotranspiration; and the spatial analysis function of ArcGIS was used to detect the spatial distribution of the evapotranspiration. In 1961-2003, the mean annual potential evapotranspiration in the Plain was 330 - 860 mm, and presented an overall decreasing trend, with the high value appeared in southwest region, low value in surrounding areas of southwest region, and a ring-belt increasing southwestward. The climatic change rate of the annual potential evapotranspiration was -0.21 mm x a(-1). The annual potential evapotranspiration was the highest in 1982, the lowest in 1995, and increased thereafter. Seasonally, the climatic change rate of the potential evapotranspiration in spring, summer, autumn, and winter was -0.19, 0.01, -0.05, and 0.03 mm x a(-1), respectively, suggesting that the potential evapotranspiration had a weak increase in winter and summer and a slight decrease in spring and autumn.