This study investigates 6(main kinds of) dominant species on Sejila Mountain in the southeast of Tibet.Statistics are gathered from 5 space factors,such as altitude,slope gradient,slope aspect,slope position and soil depth.The niche breadths of each dominant population on various spatial resources as well as the average weight(s) are calculated.Analysis and appraisal of the forest resources in this region are carried out on this base.The results show that in the virgin forest of Sejila mountain in Tibet,the sorting decrease of the niche breadth of the(main) dominant population can be listed as: Abies georgei var,Pinus densata,Picea likiangensis var.linzhiensis,Quercus aquifolioides,Sabina saltuaria,Pinus armandi.The niche metric space displays the major characteristics,which indicates that the forestry community is at a quite stable stage and equals to a climax community.

Growth of protocorm of Cymbidium eburneum induced on basal culture medium of 1/2 MS by four fungal elicitors,which were isolated from the roots of Cymbidium goeringii and Dendrobium sinens was examined in our study.The results showed that three fungal elicitors out of four considerably promoted the growth and differentiation of protocorm,and that the inducing effects were in the order of HF26>CF6>CF8.Compared with the control group,HF26 strain was found to increase the fresh weight of C.eburneum(P<0.05).The increased rates in fresh weight were 96.13%,86.86% and 61.18%,while the increased rates in dry weight were 130.70%,124.30% and 96.50%,respectively(P<0.01).In addition,CF8 strain could promote the number of roots;HF26 strain was beneficial to multiplication of protocorm;CF6 strain had a remarkable effect on seedling establishment and differentiation of root primordia.It can be concluded that different fungus have different effects on the growth of protocorm of Cymbidium eburneum in different growth stages.

According to the theory of landscape ecology,landscape structure is more related to ecological processes.Based on GIS,the changes of landscape pattern before and after the overall plan of the Moon Mountain Scenic Spot were analyzed by selecting five landscape index including landscape diversity index,dominance index,evenness index,landscape fragmentation index and landscape separation index.The results indicated that: after the planning,there was an increasing of four types of landscape in the Moon Mountain Scenic Spot.On the landscape level,there was an increasing of landscape diversity index and evenness index and a decreasing of dominance index;on the patch level,there was an increasing of the landscape fragmentation index of forest,bush,grassland and waters and the landscape separation index of forest.There was a decreasing of the landscape fragmentation index of arable land and the landscape separation index of bush and grassland.Overall,planning scheme has differential impact on environment,enhances interesting of the Moon Mountain Scenic Area,and contributes to the development of tourism activities.

By the relatedness degree of the gray system theory,the relatedness degree between the damages caused by Mikania micrantha H.B.K.to herbaceous community,herbaceous scrub community and shrub community in Guangdong Neilingding Island and the ecological factors was analyzed.The results show that the correlated degree of damages of M.micrantha to herbaceous community and environmental factors is mainly affected by the water content of soil and conductivity.On the other hand,the correlated degree of damages of M.micrantha to herbaceous scrub community and each environmental factor is not significantly different,but it is mainly affected by water content of soil,pH of soil and transparence of communities.There is also no significant difference in the correlated degree between the damages of M.micrantha to shrub community and environmental factors,but it is mainly affected by organic matter content of soil,transparence of communities and water content of soil.The sequence of the effect of all environmental factors on the damage of different communities can be listed as water content>pH and organic matter content> transparence of communities and soil nutrients.

The typical vegetation coverage in Guiyang is Karst vegetation,among which Karst evergreen conifer forest,Karst evergreen broadleaf forest and Karst evergreen shrubs are of great significance on the local ecological system.This research investigated the leaf longevity of main evergreen tree species of Guiyang Karst vegetation by taking the dominant species and companion species as the main objects in varied life-form species and computing the average life expectancy(Ex) based on life-table method.The results are as follows: ① The leaf lifespan of evergreen tree species mostly ranged from 0 to 2 years,with large variation and different replacing periods of every tree species.② Difference in leaf lifespan of varied life-form species exsited.Average leaf lifespan was relatively longer in small trees and shrubs than in large trees,but was not significantly different.③The species leaf lifespan was obviously different in varied forms of vegetation.Reckoning with the speciality of vegetation in Guiyang,the present study discussed the influencing factors of leaf lifespan and concluded that the leaf lifespan had its own specific scatter pattern in Guiyang.

The results of our research on population distribution and dynamics of the wintering Red Crown Cranes in Yancheng National Nature Reserve show that the wintering population in the area has increased from 230 in the time of nature reserve establishment to 1 128 in 2000.However,the population has decreased since then,and the number of red crown cranes recorded in the spring of 2008 is only 640.During the research a number of counting tools,including binoculars,telescopes and cameras were used.The methodologies of direct counting and literature review were used.The results indicate that the overall population of wintering red crown cranes is decreasing,and that its distribution percentage in artificial wetlands has also decreased from 76.4% in the spring of 2000 to 50.5% in 2008.Analysis of the population dynamics suggests the wintering population of red crown crane is likely to remain stable and/or to increase,while some of the population will migrate out of this region.Based on these findings,the present article discusses the conservation and management issues of the wintering red crown cranes,and proposes the establishment of an artificial wetland ecological economy.

The quality of water body in 20 medium and small reservoirs in Zhuhai was assessed using environmental quality index.The results show that the water quality of medium and small reservoirs in zhuhai is fine.Firstly,water quality in 15 reservoirs reached to the Grade II water quality standards while that in 5 reservoirs attained the Grade I water quality standards among the 20 medium and small reservoirs investigated.Secondly,the key pollutants were total nitrogen.Thirdly,the iron levels in 3 samples were over the limits of surface water and the standards for the daily drinking water.Meanwhile,the sulfide levels in 2 samples were over the standards for the daily drinking water.Finally,all of them need further treatment before serving as drinking water.

Influenced by tides,pollutants in rivers can be transferred and changed a lot.This paper focus on how to set the reasonable sections for monitoring and to establish in-phase monitoring project that in accord with the law of water quality and quantity of the reach,so as to provide service for finding out the contamination input and getting more actual evaluation of water quality.It can be found,from the in-phase monitoring of water quality and quantity of the reach at the junction of Guangzhou and Foshan,that the sum transport of COD into this area is 288.8 t per day,and the sum transport of NH₄⁺-N is 88.8 t per day,and that using representative period method to calculate the contamination input and using individual item law to evaluate water quality are more credible and reasonable.Besides,the reason responsible for worse water quality is that contamination carrying capacity goes over environmental capacity of the reach.Intensifying surface pollution governance of the upstream areas of the reach,and establishing water quality automatic monitoring station in important water supply places to monitor real-time water quality are effective measures to ensure safety of water taking in different seasons.

Great attention has been paid to the mycorrhizal studies over the world because of the wide use of mycorrhizas.The paper summarizes four new characters of mycorrhizal studies during the last 10 years,particularly the related studies of mycorrhizas in China;Then it sums up the application of ectomycorrhiza in introduction,nursery,adversity planting,disease and pest control in the root of plant,and edible fungus production.It also proposes the effects of arbuscular mycorrhizal fungi on forest,field crops,vegetables,flowers and ecological restoration,and the application of orchid mycorrhizal fungi in the seed germination and growth of orchid.Finally,four aspects on mycorrhizal studies at present referring to its research and current application in the agricultural and forestry production,and some correspondingly reasonable suggestions have been put forward in this paper.

Nano-and picoplankton exist in almost all kinds of marine ecosystems,and distribute in all the oceans of the world.In most sea areas,nanoflagellate is the most abundant nanoplankton species.Prochlorococcus dominants in oligotrophic seas.Synechococcus,pico-eukaryotes and heterotrophic bacteria are prevalent in nutrient-rich waters,and are dominant in eutrophic waters of temperate,tropic and subtropical zones.The main controlling factors include temperature,salinity,irradiation,nutrient loading,hydrological stability and grazing pressure,which vary with the difference of areas and result in various population abundances and community structures.This paper reviewed the detecting methods on marine nano-and picoplankton populations,as well as their distribution characters and environmental impacts.This paper also put forward to the key study area and development trends on nano-and picoplankton research in the future.

Soil seed bank includes all living seeds existing both in litter and in soil.Investigation of the seed and spore bank has become a recognized and indispensable part of plant ecology now and has been an active research area.The soil seed bank is one of the life history stages of plant populations,which is called subpopulation stage and acts as the base of settling,living,reproducing and spreading of plant populations.The theory of soil seed bank is regarded as the basic theory of community ecology and restoration ecology,an important mechanism for natural regeneration in degraded forest ecosystems,and has become a hot issue in plant ecology.With its development,the methods of soil seed bank research are more scientific and precise;meanwhile the content is updated and supplemented constantly and the fields of research include botany,genetics,ecology,weed science,agronomy and other sciences.Up to now,a comparatively full and complete framework of theory in soil seed bank has been achieved,which can be summarized as following: 1.development and direction of soil seed bank;2.characteristics of the soil seed bank;3.dynamics of soil seed banks;4.classification of soil seed bank;5.methods used in the seed bank research;6.its contribution to plant ecology.