Genetic Structure of Reaumuria soongorica Population in Fukang Desert, Xinjiang and Its Relationship with Ecological Factors

Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diversity and differentiation were revealed in the population of R soongorica by 15 random primers. One hundred and thirty-six individuals from seven subpopulations were sampled in the study. Seventy-one loci have been detected, and among them 69 were polymorphic. The mean proportion of polymorphic loci (PPB) was 97.18%. The analyses of Shannon information index (0.307 5), Nei's gene diversity (0.312 7) and G(ST)(0.312 0) indicated that there were more genetic variations within the subpopulations than those among the subpopulations. The results of AMOVA analysis showed that 61.58% of the genetic variations existed within subpopulations, and 38.02% among the subpopulations. The gene flow among the subpopulations of R soongorica (Nm = 1.102 8) was much less than that of the common anemophytes (Nm = 5.24), so genetic differentiation among the subpopulations occurred to some extent. Additionally, through the use of clustering and the correlation analyses, we found that the genetic structure of natural population of R soongorica was related to some ecological factors (soil factors mainly) of the oasis-desert transition zone. The genetic diversity level of R soongorica had negative correlation with the content of total soil P and Cl significantly (P < 0.05). On the contrary, it had significant positive correlation with CO32- (P < 0.05), showing that the distribution of the individuals of R soongorica in the sampled areas correlates with certain soluble salt. Furthermore, the genetic diversity of the natural population of R soongorica increased with the decreasing of the content of soil organic matters, water, total N and total P in soil. The paper concluded that the microenvironment ecological factors played an important role in the adaptive evolution of R soongorica population.

Plant Type and Its Effects on Canopy Structure at Heading Stage in Various Ecological Areas for a Two-line Hybrid Rice Combination,Liangyoupeijiu

A two-line hybrid rice combination, Liangyoupeijiu, was used to estimate several factors of plant type, and environmental models for these factors at the heading stage were established using the data of eight ecological experimental sites in 2006 and 2007. According to climatic data from 1951 to 2005, the differences in those factors and their effects on plant canopy were analyzed for four rice cropping areas in China, including South China, the middle-lower reaches of the Yangtze River, Sichuan Basin, and river valley in Yunnan, China. The thickness of leaf layer （the distance from pulvinus of the third leaf from the top to the tip of flag leaf） and distribution of leaf area could be used as candidate indices for the plant type of a rice canopy.

Land Use Structure in Wuhai City on Basis of Ecological Green Equivalence

The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.

Ecological Structure and Prediction Equations for Estimating Tree Age, and Dendometric Parameters of <i>Acacia senegal</i>in the Senegalese Semi-Arid Zone—Ferlo

The development of equations to predict tree height, crown diameter, crown depth from stem diameter of a tree species enables arborists, researchers, and urban forest managers to model costs and benefits, analyze alternative management scenarios, and determine the best management practices for sustainable forests. The objective of this study was to develop regression prediction models for tree age, tree height, crown diameter, crown ratio and crown depth for A. senegal growing in Ferlo, in the northern Senegal. Four plantations of different years old (ISRA, 10 years old plantations, Ndodj, 8 years old plantations, Boulal, 5 years old plantations and Déali, 4 years old plantations) were selected. The following dendometric variables: crown height, crown diameter, stem diameter at the breast height, stem basal diameter (at 0.30 m) and the height from the tree base to first branch were measured on a total of 489 trees. The results suggested that the ecological structure of the different year old A. Senegal plantation revealed a bell-shaped form with left dissymmetric distribution indicating a predominance of individuals with small diameter at breast height. Allometry study of A. Senegal showed highly significant positive correlations (p = 0.00) between stem diameter at breast height, stem basal diameter, tree height, crown diameter and crown depth. Positive correlations were also found between crown diameter, tree height and crown height. Prediction models derived from these relationships can be used to estimate the tree height, stem diameter at breast height and crown depth from crown diameter with greater precision. As for A. Senegal age estimation, the established model is not strong as it can explain only 49.1% of the age variation.

An approach to the influence of industrial structure on urban ecological environment

dustrial structure is key link of man's action to ecological environmental system. Its combina-tion type and intensity determine, to a great extent, economic benefit, resources utilization efficiency andstress on environment. So the assessment to the rationality of industrial structure is of great importance. Inpresent paper, the research theories and ways on relationship between industrial structure and ecological en-vironmental systems were put forward. Environmental carrying capacity (ECC) was adopted to describequantitatively the relationship between man's social economic activity and environmental resources. At theend of this paper. analysis was made with Benxi City as an example.

Study on Changes of Industrial Structure and Its Ecological Environment Benefit in Shaanxi Province

[Objective] To reduce influences of adjustment of regional industrial structure on ecological environment,promote coordinated development of regional economy and ecological environment,and improve the relationship between human beings and natural environment. [Method]Based on the statistical data of Shaanxi Province during 1978- 2013,the ecological environmental impact index and effect index of industrial structure in Shaanxi Province were calculated,and then the ecological environment benefit of changes in industrial structure in Shaanxi Province from1978 to 2013 was assessed quantitatively. [Result]The impact of changes in industrial structure on ecological environment in Shaanxi Province was moderate,but later changes in industrial structure had greater influences on ecological environment than before. [Conclusion]Industrial structure in Shaanxi Province should be optimized further to ensure the healthy development of ecological environment.

Ecological Structure and Fruit Production of African Fan Palm (<i>Borassus aethiopum</i>) Populations

Ecological structure and fruit production of African fan palm stands in Benin were studied on the basis of surveys laid out in ten (10) populations located in three ecological zones. Dendrometric and fruit production parameters such as: diameter at breast height (dbh), total height (TH), number of fruit bunch per tree, number of fruits per tree, number of seeds per fruit, fruit length and width were measured on all African fan palm trees within thirteen (13) plots of 1,000 m2. Diameter and height classes distribution of the palms in each ecological zone adjusted to Weibull distribution showed a bell shaped curve with left dissymmetry, characteristic of young stands (form coefficient between 1 and 3.6). African fan palm stem number was 156 trees/ha. Variation of dbh, TH, number of fruit bunch per tree were highly significant between populations and ecological zones (P < 0.05%). Trees from Sudanian zone were highly grown (mean dbh = 52.2 cm) while those of Sudano - Guinean transition zone were less (mean dbh = 32.73 cm) and dominated by female trees. African fan palm stands of Pahou is suitable for seed collection for in situ conservation of the species while those of Ouorghi and Akomiah could provide fruits for edible hypocotyls production.

Study on ecological structures of coastal lakes in Antarctic continent

Coastal region on the Antarctic continent, where it is under the influences both of ocean and ice sheet, as well as frequent human activities, could be considered as a fragile zone in Antarctic ecological environment. There are many lakes in coastal region, showing much differences from each other in physical-chemical features because of individual evolutionary history in their geographical environments, and suffering from different outside factors, such as climate changes and precipitation. Thus, it results in respective biological distribution and ecological structure in lakes. The present paper reports the results from the studies of chemical components, species distributions and community structures, which mainly consisted of planktons in lakes in the Vestfold Hills (68°38′S, 78°06′E), and the Larsemann Hills (69°30′S, 76°20′E), East Antarctica. It also treats the biological diversities and nutrient relationships of these different types of lakes. So as to provide more scientific basis for monitoring of climate changes and environmental protection in Antarctica.

The Research of Ecological Nutritional Organs of Invasive Plants Structural Characteristics

[Objective] The aim of this paper was to discuss the adaptability of ecological nutritional organs of invasive plants.[Method] By dint of high-definition display of plant tissue crystal method and paraffin section method,the vegetative organs root,stem and leaf cross-section of the organizational structure of Asteraceae Ambrosia trifida L.ragweed（Ambrosia trifida L.）in the suburbs of Changchun City in Jilin Province were inspected.[Result] The structural basis for ecological invasive plant Ambrosia trifida L.vegetative organs was mainly through strengthening the roots of water absorption and transporting function,increasing the water storage function of leaf and stem,reducing the water absorption of stem and leaf for plants to promote water absorption and to enhance the assimilation of leaves to achieve a variety of complex environmental conditions in the rapid growth and development in order to achieve an ecological invasion.[Conclusion] The study provided reference for the biological fundamental research of Ambrosia trifida L.

A STUDY ON STRUCTURAL ANALYSIS OF SUBURBAN ECOLOGICAL AND ECONOMIC SYSTEM ─Taking Tianjin Suburbs and Counties for Example

Along with the development of urban economy. the growth of urban population and the increase of needs of urban society, the suburban ecological and economic system changes constantly and profoundly in its structure and function.Intensifying the research on structural analysis of suburban ecological and economic system is of great significance for grasping light the laws governing the development and evolution of the suburban ecological and economic system and leading this system onto a path of sound circle. By making comprehensive use of the cluster analysis and latent structural analysis the author attempts to explore a new avenue of revealing the structure of suburban ecological and economic system, taking Tianjin suburbs and counties as an example. The results obtained from the above-stated analyses show that it is entirely possible and extremely effective to study the structure and function of suburban ecological and economic system and provide scientific evidence for control of this system by using mathematical methods and statistical analyses.

Study on Development of the Leaf Structure of Podocarpus macrophyllus var. maki Endl.

The leaf development of Podocarpus macrophyllus var.maki Endl.started from the leaf primordium formed by the cell division in shoot apical meristem.During the leaf development,three resin canals from the inferior part of vascular bundles firstly began to differentiate,then protoxylem in vascular bundles differentiated from adaxial side to abaxial side.Meanwhile,a layer of parenchyma cells from the inferior part of protoderm developed into the sclerenchyma,which played an important role in supporting young leaves.When xylem became mature basically,transfusion tissue,phloem and accessory transfusion tissue began to differentiate,so mesophyll tissue finally differentiated into developmental palisade cells and sponge cells.The thicker cuticle was formed in the lateral side of epidermal cells at the same time of differentiation and development for the inner structure of leaves.Therefore,the developmental palisade cells and the cuticle in the leaf structure of Podocarpus macrophyllus var.maki Endl.is greatly significant for photosynthesis and transpiration when it grows in arid and cold regions.

Exergy and ecological modelling of lake environment

The thermodynamic theories and ecological theories can be integrated effectively by exergy(biogeochemical energy of the system) to study the environmental problems of the lakes and reservoirs. In this paper, the applications of exergy in the ecological modelling of lake environment were reviewed. Results showed that exergy can be used as a goal function to estimate the parameters of the ecological model for lakes and reservoirs and to develop the structural dynamic models accounting for the changes in lake ecosystems, and as an ecological indicators for the development and evolution of lake ecosystems.

The Effect of Ecological Factors on the Indexes of Yield Property Equation and Quantitative Analysis

The mechanism of action of ecological factors affecting crop growth and development was complicated. In order to study the relationships between ecological factors and the indexes of yield property equation and determine the main ecological factors affecting yield, using 3-yr field experimental results for different yielding spring maize （Zea mays L.） populations and the relative meteorological observation data in Huadian of Jilin Province in China, and analyzing on the base of the yield property equation （MLAI × D × MNAR × HI = EN × GN × GW）, the main ecological factors were screened, and further mechanisms of action affecting yield were analyzed. Stepwise regression analysis showed that yield was affected mainly by effective accumulated temperature, daily mean minimum temperature, daily mean maximum temperature in July, the ratios of growth days, and the sunshine hour before and after silking. In yield property equation, four indexes of MLAI, growth days, ear number and grain number （total grain number） affected principally yield, the ecological factors affecting predominantly yield were effective accumulated temperature, daily mean temperature, daily mean minimum temperature, daily mean maximum temperature in July, the ratios of growth days, rainfall, accumulated temperature, and sunshine hours before and after silking. Combined with the two analytical methods, it could be deduced that the temperature and the allocated ratios before and after silking of ecological factors were the key factors to achieve high yield. Therefore, appropriate sowing data should be adjusted to achieve the suitable temperature indexes during the whole growth stage and the rational allocated ratios of ecological factors before and after silking.

STUDY ON ECOLOGICAL SPACE OF URBAN AGGLOMERATION-Taking Wuxi City as an Example

From the angle of ecology,urban agg lomeration presents relevant types of landscape structure,which in-clude Patch,Corridor and Matrix.There are different landscape feature s and different problems in differen t development phases.This paper has put forward fi ve basic conditions for security pattern of landscape ecology of urban agglomeration,described quantitatively the featu res for landscape ecology in Wuxi,an d analyzed ecological background of spatial expan-sion and spatial organization of urb an development in Wuxi.From the angle of ecological land use and non-ecological land use,the paper has analyzed the featu res of land use and ecological distribution of land in the urban area.The s patial mod-el of cities and towns in Wuxi is composed of one metropolis,two urban zones and three development axes.This th esis has planned preliminarily ecologic al protection network at four levels in the urban region according to four layers.At last,combining landscape ecology with ur ban space,a tentative security pattern of landscape ecology has been pla nned in Wux-i,namely Source-Buffer Zone and Metropolis,Radiating Routes and Expan sion Direction of City,Strategic Point and Interac-tion between Cities and Towns,Inter-Source Linkage-Corridor of a Stabl e Landscape Structure.

Relationships Between Community Structure and Environmental Factors in Xixiakou Artificial Reef Area

The construction of artificial reefs has unparallelly developed for a few decades in China.Artificial reefs can be used to manage and conserve commercially exploited fish and crustacea.However,their suitability as ecological niche is poorly characterized.Therefore,in this study,we detected the seasonal variation of community biodiversity and the corresponding driving environmental factors.We also explored the relationships between dominant species and environmental factors to identify appropriate ecological niche areas.Different statistical analysis methods were used to assess species distribution within an artificial reef area in Xixiakou during nine sampling events in four seasons between 2017 and 2018.Non-metric multidimensional scaling(NMDS)and cluster analysis results indicated that the components of community can be divided into two clusters.Complexity of community,which is exhibited by species number,biodiversity,and catch per unit effort(CPUE),was significantly higher in summer than in other seasons.Generalized additive model(GAMs)results revealed the significant effects of temperature and chlorophyll a on the community structure.Sebastes schlegelii,Hexagrammos otakii,Conger myriaster and Charybdis japonica were the dominant species in four seasons.GAMs results indicated that temperature,dissolved oxygen(DO),pH and chlorophyll a affect the CPUE of dominant species significantly.The distinct suitable ecological niche for each dominant species was found in this study.For example,Charybdis japonica preferred to live in the area with 20.7–22.1℃,dissolved oxygen 7.07–7.15 mg L−1 and salinity 31.8–31.9.The results of this study are beneficial to resource conservation and fishery management.

Role of permafrost in resilience of social-ecological system and its spatio-temporal dynamics in the source regions of Yangtze and Yellow Rivers

Permafrost is one of the key components of terrestrial ecosystem in cold regions. In the context of climate change, few studies have investigated resilience of social ecological system(SER) from the perspective of permafrost that restricts the hydrothermal condition of alpine grassland ecosystem. In this paper, based on the structural dynamics, we developed the numerical model for the SER in the permafrost regions of the source of Yangtze and Yellow Rivers, analyzed the spatial-temporal characteristics and sensitivity of the SER, and estimated the effect of permafrost change on the SER. The results indicate that: 1) the SER has an increasing trend, especially after 1997, which is the joint effect of precipitation, temperature, NPP and ecological conservation projects; 2) the SER shows the spatial feature of high in southeast and low in northwest,which is consistent with the variation trends of high southeast and low northwest for the precipitation, temperature and NPP, and low southeast and high northwest for the altitude; 3) the high sensitive regions of SER to the permafrost change have gradually transited from the island distribution to zonal and planar distribution since 1980, moreover, the sensitive degree has gradually reduced; relatively, the sensitivity has high value in the north and south, and low value in the south and east; 4) the thickness of permafrost active layer shows a highly negative correlation with the SER. The contribution rate of permafrost change to the SER is-4.3%, that is, once the thickness of permafrost active layer increases 1 unit, the SER would decrease 0.04 units.

Identifying Indicator Species in Habitats Created by Coastal Structures

In this paper, three approachs were developed to find indicator species from the habitat created by coastal structures. These approachs consist of a model of species co-occurrence probability, a model of k-environmental factor probability and a composite model. Simultaneously, a case study was conducted in Hsinchu Fishing Port of north-western Taiwan. Based on the aforementioned models, three primary producer species, Ahnfeltiopsis flabelliformis, Chondrus ocellatus and Sarcodia montagneana, were chosen as the indicator species which had the highest co-occurrence probabilities and showed greater tolerance to more critical environment. It is imperative to understand how the three species under particular co-occurring conditions and environmental factors influence the composition of sessile assemblages in coastal water. The results indicate that for the purpose of increasing biodiversity, these models are feasible to find indicator species of artificial structures, and to help make it possible to design coastal structures based on biological considerations. This study provides an innovative approach for further advanced application in the artificial habitat of coast management.

Hot Issues in and Directions for Plant Root Research in Ecological Remediation

The mining activities destroy the natural vegetation and the land, pollute the environment in many aspects, and more and more attention has been paid to the ecological restoration in the mining area. Phytoremediation is the greenest tech- nical means of ecological restoration and reconstruction in the mining area. The root system is a direct organ that absorbs nutrients and water dudng phytoremediation, which is of great significance to ecological restoration. In order to explore the hot issues of plant root system in phytoremediation, the current situation of root system under the stress of heavy metal pollution and drought stress and geotechnical stress was reviewed, and the improvement effect of root exudates on rhizosphere environment was briefly introduced. The future direction of root system in ecological restoration and environmental protection was proposed on the basis of the existing research and existing problems.

Landscape changes and their ecological eff ects of Miaodao Archipelago with human disturbances and under natural conditions in the past 30 years

The modern landscape patterns of islands usually show obvious spatial heterogeneity and complex ecological effects due to the vulnerability of ecosystems with natural characteristics under increasing human activities.In this work,we studied the variation in landscape pattern of the Miaodao Archipelago in Bohai Sea,North China,from 1990 to 2019,and an evaluation index system was established to explore the impacts of natural conditions and human disturbances on the ecological effects in the pressure-state-response(PSR)framework.Empirical analysis was conducted on the natural conditions,human disturbances,and ecological effects.The results show that forest was the main component of the landscape pattern in the archipelago.Both of the areas offorest and construction land were increasing,and the areas of cropland and grassland were declining.Other landscape types changed slightly,and the landscape fragmentation was increasing.The natural condition exhibited positive effects while human disturbance showed negative effects on the local ecology.Human disturbances come mainly from shoreline use while the natural conditions were mainly from the elevation change.The ecological effects were resulted mainly from the net primary productivity and water yield.

Effects of transgenic poplar clone 741 with insect resistance on structure and diversity of arthropod community

Arthropod community structure and diversity were investigated in transgenic insect-resistant hybrid poplar 741 field trial plots, which had five isogenic clones with two genes （Bt. toxin [Cry IAc] and arrowhead proteinase inhibitor [API]） in comparison to control plots. Transgenic poplar clones were investigated according to their insect resistance （high and medium resistant clones）, being systematically probed into varying levels with feeding tests before. Investigations were carded out during three years （2002, 2003 and 2005）. The results indicated that among the basal species, transgenic plants in general had lower amounts of phytophagous insects, and an increased quantity of neutral arthropods such as saprophytic and strolling species. Among the top and intermediate species in transgenic variants, the quantity of predatory natural enemies was increased, while the amount of parasitoid ones was slightly reduced. The arthropod community characteristic indices were analyzed from different aspects in the three variants. It was discovered that, not only the characteristic indices of the whole arthropod community, but also the characteristic indices of the sub-communities （such as natural enemy, pest and neutral arthropods） and the functional groups categorized by their feeding patterns, showed a higher diversity and evenness and a lower dominancy concentration indices in the high-resistant and medium-resistant plots compared with the control. Transgenic poplar 741 showed improved ecological effects both in partial and total aspects. It could be concluded that composition and structure of the arthropod community in plots with transgenic insect-resistant poplar were turned to be more reasonable and itsdiversity and stability was enhanced.