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1.
Hollows of veteran trees (i.e., rot holes) provide habitat for many rare and threatened saproxylic invertebrates. Rot holes are highly heterogeneous, particularly in terms of substrate and microclimate conditions. There is, however, a dearth of information regarding the differences in biological communities inhabiting rot holes with different environmental conditions. Invertebrates were sampled from European beech (Fagus sylvatica) rot holes in Windsor, Savernake, and Epping Forests (United Kingdom). For each rot hole, physical and environmental conditions were measured, including tree diameter, rot hole dimensions, rot hole height, substrate density, water content, and water potential. These parameters were used to assess the influence of environmental conditions and habitat characteristics on invertebrate communities. Rot hole invertebrate communities were extremely diverse, containing both woodland generalist and saproxylic specialist taxa. Large variation in community structure was observed between rot holes and across woodlands; all sites supported threatened and endangered taxa. Environmental conditions in rot holes were highly variable within and between woodland sites, and communities were predominantly structured by these environmental conditions. In particular, turnover between invertebrate communities was linked to high β-diversity. The linked heterogeneity of environmental conditions and invertebrate communities in rot holes suggests that management of deadwood habitats in woodlands should strive to generate environmental heterogeneity to promote invertebrate diversity. Additional research is required to define how management and conservation activities can further promote enhanced biodiversity across rot holes.  相似文献   

2.
The key environmental benefits of faba bean are its ability to fix atmospheric nitrogen symbiotically under a broad spectrum of environmental conditions and making this renewable resource available to show positive precrop effects in diversified crop rotations. Non-nitrogen precrop effects entail potential benefits via increased availability of soil phosphorus to the subsequent crops. Faba bean acts as a break crop in intensive cereal-dominated crop rotations.  相似文献   

3.
根据味精废水的水质特点研究了酵母菌处理味精生产废水中对COD的影响。考察Tpn值、温度和发酵时间对酵母菌处理味精生产废水中COD的去除效果。结果表明,酵母菌对于环境条件的要求很宽松,应用酵母菌处理味精废水具有良好的环境和经济效益。  相似文献   

4.
在调查福州城市住区环境现状的基础上,分析了福州城市湿地及住区的现状及存在的问题,探讨城市住区湿地环境建设的对策,同时,较系统地研究了将湿地生态空间设计引入现代住宅小区环境设计与创造方法等,以期对生态住区空间建设提供指导性建议。  相似文献   

5.

Background  

The relationship between environmental variation and induction of heat shock proteins (Hsps) has been much documented under experimental conditions. However, very little is known about such induction in natural populations acclimatised to prevailing environmental conditions. Furthermore, while induction of stress proteins has been well documented in response to environmental contaminants and thermal stressors, little is known about whether factors, such as extreme salinity, are also potential inductors. The black-chinned tilapia Sarotherodon melanotheron is unusual for its ability to colonise estuarine environments in West Africa that are characterised by extremely high salinities. The relationships between mRNA levels of the 70 kDa heat shock protein (Hsp70) and Na+, K+-ATPase1α (Naka) in the gills, environmental salinity, and a life-history trait (condition factor) were investigated in wild populations of this species sampled from three locations in the Saloum estuary, at salinities ranging from 40 to 100 psu.  相似文献   

6.
There are many methods available for sampling spray drift, and a great variety of estimates of spray drift have been published. Available data on spray drift were collected from different studies and the measurements of spray drift were analysed to determine similarities and differences between the individual studies. Each of the methods varied significantly in their estimates of spray drift. This variation was due to many factors that differed between the published sources, such as environmental conditions, cropping system, equipment used and the tracer used. It is suggested that in order to compare drift measurements between published studies, measurement techniques and sampling distances must be standardised, and environmental conditions (humidity and temperature) should be restricted to within certain boundaries in the field, and controlled within artificial tests, unless, of course, the effect of this variable on drift is being examined.  相似文献   

7.
通过对福建省香蕉主产区(漳州市)香蕉园采集74个0~20 cm土层的土壤样品进行分析,分别以福建省土壤环境背景值、GB 15618-1995《土壤环境质量标准》二级标准、NY/T 391-2000《绿色食品  产地环境技术条件》为参照标准,比较研究了丘陵山地、城镇周边、道路周边3种不同环境蕉园土壤Cd、Pb、As、Hg、Cr、Cu 6种重金属元素的含量特征、元素间的相关性。结果显示:福建省香蕉主产区丘陵山地、城镇周边、道路周边3种不同环境蕉园土壤,各种重金属含量有明显差异。3种不同环境蕉园土壤6种重金属元素之间的相关性发生了一定的变化。与福建省土壤环境背景值比较,Hg含量在所有的土壤中,Cd、Pb含量在城镇周边、道路周边蕉园土壤有明显的富集,As、Cr、Cu含量接近或低于福建省土壤环境背景值;3种不同环境蕉园土壤样品超标率Cd、Pb、Hg较为严重,As超标样本集中在道路周边蕉园土壤。6种重金属平均含量均符合国家土壤环境质量二级标准及NY/T 391-2000指标要求;但仍有部分样品超标,特别是Pb、Hg应引起重视。福建省香蕉主产区发展香蕉绿色食品生产适宜的产地依次为丘陵山地、城镇周边、道路周边的蕉园。  相似文献   

8.
改善夏秋绿茶滋味品质研究现状   总被引:9,自引:0,他引:9  
敬廷桃  钟应富  袁林颖  周正科 《茶叶》2006,32(3):133-135
本文在论述绿茶滋味构成和环境条件对滋味影响的基础上,总结了目前改善夏秋绿茶滋味品质的技术措施,并建议重点发展茶林间种、茶果间种、茶粮间作等模式的复合生态茶园,推广蒸汽杀青和微波干燥等技术措施,以进一步改善夏秋季绿茶滋味品质。  相似文献   

9.
Summary Long-day-adaptedSolanum phureja clones were assessed for resistance to blackleg caused byErwinia carotovora subsp.atroseptica under field and controlled environmental conditions over two years. In the field, twenty-two of the twenty-three clones ofS. phureja assessed were as resistant to blackleg as the commercial cultivar Ailsa, the most resistant control, and were significantly (P<0.001) more resistant than the intermediate and susceptible cultivars Wilja and Estima, respectively. Under controlled environmental conditions, resistance in commercial cultivars was more easily overcome. However, 18 of the 21S. phureja clones assessed were significantly more resistant to blackleg than these cultivars.  相似文献   

10.
Plants have evolved delicate mechanisms to cope with environmental stress. Following exposure to environmental stimuli, extracellular signals are perceived and transmitted through signal transduction cascades. Upon receipt and transmission of the signals, a number of stress-related genes are induced, leading to stress adaptation in plant cells. Rice, which is a critical food grain for a large portion of the world’s population, is frequently impacted by several abiotic stressors, the most important of which are drought, salinity, and cold. Exposure to environmental conditions outside of acceptable tolerance ranges can negatively affect rice growth and production. In this paper, a review of rice responses to abiotic stress is presented, with particular attention to the genes and pathways related to environmental stress tolerance. It is apparent that, while progress has been made in identifying genes involved in stress adaptation, many questions remain. Understanding the mechanisms of stress response in rice is important for all research designed to develop new rice varieties with improved tolerance.  相似文献   

11.
根据广西沿海地区豇豆生长发育气候环境条件和病虫发生为害特点,提出通过创造有利于豇豆正常生长发育而不利于病虫发生为害的栽培环境条件,有效地改善豇豆生育状况,使植株健壮生长,增强自身抗逆性,减少、控制病虫滋生、蔓延和为害,控制豇豆产品农药残留不超标,实现豇豆健身栽培。  相似文献   

12.
Summary The effect of environmental conditions on seed tuber production from true potato seed (TPS) in nurseries was evaluated in different growing periods during two seasons in Egypt. In the autumn season, high soil and air temperatures reduced emergence and initial foliage development of early-sown seedlings, and decreased tuber yields. In late-sown seedlings low night temperatures and short daylengths caused early tuberization, poor foliage development and low tuber yields. In the spring season, low temperatures and short daylengths resulted in a slow initial foliage development and early haulm-tuber competition for assimilates in early-sown seedlings. However, tuber yields were higher than for late-sown seedlings, presumably because net assimilation and assimilate partitioning to the tubers were impaired by above optimum air and soil temperatures in May and June. Slow development of true seed-sown plants caused a high sensitivity towards adverse environmental conditions and would limit yielding ability in Egypt.  相似文献   

13.
The preference intensities of Japanese Medaka Fish (Japanese killifish, Oryzias latipes) to the three environmental factors of water depth, current velocity, and cover are discussed in this paper. Mathematical models of preference intensities for Japanese Medaka Fish to the three environmental factors were constructed in laboratory open-channel experiments. A simple genetic algorithm for the optimal functional representation of preference intensity was introduced. The models were then verified by on-the-spot examinations. The results indicated that the maximum preference level of Japanese Medaka Fish was a water depth of 9.4 cm and a current velocity of 2.8 cm/s. The all-cover condition was considerably high compared with other cover conditions. The relative weights of the three environmental factors were 0.32 for depth, 1.0 for velocity, and 0.66 for cover, when the maximum weight was normalized. The weight values suggested that the environmental preferences of Japanese Medaka Fish were not greatly affected by water depth. Judging from the agreement between the predicted and observed distributions in considering the two factors of current velocity and cover, these two factors obviously affected the environmental preferences of Japanese Medaka Fish.  相似文献   

14.
Crop models should predict growth and yield under a wide range of environmental conditions. General use of models can only be accomplished if genetic inputs are incorporated into the model to account for genetic variability in response to environment and management. This study summarizes existing knowledge on genetic variables and related environmental responses for potato and describes procedures for collecting data to estimate these variables for several important growth processes. These genetic inputs will be used to incorporate genetic variability in modeling potato growth and tuber yield.  相似文献   

15.
The western tarnished plant bug, Lygus hesperus Knight, overwinters as a diapausing adult in response to short day lengths. Once environmental conditions are favorable, the bugs revert to an active reproductive state. To determine the impact on life-history traits of diverting resources toward diapause rather than oogenesis during early adulthood, diapausing and nondiapausing L. hesperus females were reared from the same cohorts. Body mass, ovarian maturation, ovipositional activity, and survivorship were monitored starting either at the time of release from diapause-inducing conditions or at adult eclosion for diapausers and nondiapausers, respectively. Females that had gone through 2 wk of diapause were larger and able to mobilize the resources necessary for oogenesis faster than nondiapausers, initiating oogenesis and ovipositing sooner and at a faster initial rate. However, lifetime egg production and average daily rates were similar for both groups. Postdiapausers lived longer than nondiapausers by an average of 19 d, which is five more than the 2-wk period when they were reproductively senescent. Overall, the results indicate that short-term diapause does not have a negative impact on life history. Furthermore, the extra endogenous resources stored during diapause may be able to enhance the alacrity with which the female can take advantage of improved environmental conditions and may prolong life by shielding the females against environmental stressors such as temperature extremes, oxidative agents, or food deficits.  相似文献   

16.
To understand aquatic environmental deterioration due to the anoxic state in an organically polluted water body, water quality dynamics under anaerobic conditions were examined through beaker-scale water quality monitoring. This study focused on the dynamic properties of NO3–N, NH4–N, PO4–P, and sulfide from the biochemical reactions point of view, and based on anaerobic respiration activities, such as denitrification, iron reduction, and sulfate reduction. The specific aims of this study were to quantitatively estimate the impacts of the oxidative/reductive state of the sediment surface and the high/low concentrations of dissolved organic matter on the dynamic properties of water quality under anaerobic conditions. The beaker-scale water quality monitoring was carried out through continuous measurements of dissolved oxygen and oxidation–reduction potential (ORP), as well as periodic observations of water quality parameters for six cases that are composed from combinations of three experimental conditions: (1) concentration of dissolved organic carbon (DOC); (2) redox state of the sediment; and (3) concentration of NO3–N. As a result, the temporal changes in ORP under anaerobic conditions exhibited a five-step process of decline without these conditions. Also, high DOC concentrations and oxidative states of the bottom mud accelerated the release of PO4–P and sulfide generation through promoting biological iron reduction and sulfate reduction, because these conditions increase respiratory substrates for anaerobic microorganisms, such as iron and sulfate-reducing bacteria. It was concluded that our results would provide important information about the mechanisms of aqueous environmental deterioration due to organic pollution in closed water bodies.  相似文献   

17.
热带地区拟南芥栽培技术及基因转化体系的构建   总被引:3,自引:0,他引:3  
由于气候、温度、湿度等原因,拟南芥在热带地区的应用一直受到限制。笔者结合海南气候特点,在培养介质、播种、湿度、光照条件及转化方法等方面进行了探索,摸索出拟南芥栽培、实验室培养和基因转化的条件,为在海南利用模式植物拟南芥进行重大基础研究提供了详实的数据资料。  相似文献   

18.
Wheat grain yield and flour quality are strongly influenced by the effects of environment during grain fill. Environmental variables such as temperature, water and fertilizer influence the rate and duration of wheat grain development, protein accumulation and starch deposition in unique ways, and by different mechanisms. The effects of environment are superimposed on the intrinsic temporal patterns of gene expression during grain development. Integration of genomic and proteomic studies with developmental studies under controlled environmental conditions should make it possible to resolve complex patterns of gene expression during grain development, pinpoint key regulatory processes that are influenced by the environment, and reveal the molecular basis for environmental impacts on flour composition and quality.  相似文献   

19.
Abiotic stress caused by increasing temperature and drought is a major limiting factor for wheat productivity around the world. Wheat plays an important role in feeding the world, but climate change threatens its future harvest and nutritional quality. In this study, grain iron (Fe) and zinc (Zn) concentrations of 54 wheat varieties, including CIMMYT derived historic and modern wheat varieties grown in six different environmental conditions, were analyzed. The objective of the study was to evaluate the effect of water and heat stress on the nutritional value of wheat grains with a main emphasis on grain protein content, Zn and Fe concentrations. Significant effects of environment on protein content and grain micronutrients concentration were observed. The protein and Zn concentrations increased in the water and heat stressed environments, whereas Zn and Fe yield per unit area was higher in non-stress conditions. The results suggest that genetic gains in the yield potential of CIMMYT derived wheat varieties have tended to reduce grain Zn, in some instances; however, environmental variability might influence the extent to which this effect manifests itself.  相似文献   

20.

Background  

Because moisture and temperature influence the growth of fungi, characterizing weather conditions favorable for fungi may be used to predict the abundance and richness of fungi in habitats with different climate conditions. To estimate habitat favorability to fungi, we examined the relationship of fungal abundance and species richness to various weather and environmental parameters in the Intermountain West. We cultured fungi from air and leaf surfaces, and collected continuous temperature and relative humidity measures over the growing season at 25 sites.  相似文献   

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