农业生态系统和农业生态学的几个问题探讨

一、农业生态系统的概念自1935年英国植物生态学家坦斯利(Tansley,A.G.)提出生态系统这个术语以后,随着生态学的发展,它被广泛应用于生物结构的各个领域和层次。应用于农业生产领域,便产生了农业生态系统的概念。生态系统作为一个实体,是由下列三个部分组成的,即①实体内生存的所有生物体;②与这些生物     

农业生态安全及其生态管理对策探讨

对生态安全和农业生态安全的基本内涵进行了探讨。认为生态安全是指不同尺度的生态系统及其生物要素、环境要素、资源要素等在数量、质量及其相互作用关系上的一种和谐、健康、稳定的状态和水平。农业生态安全包括农业环境安全、农业资源安全、农业生物安全和农业产品安全等几个方面的内容。提出了一系列农业生态安全管理对策 ,包括 :①加强农业生态安全管理 ,发展生态产业 ;②加强对现有资源与生态系统的保护、培育与可持续利用 ;③保护农业生物多样性 ,保障生物安全 ;④加强农业综合抗灾能力建设 ;⑤加强农业生态安全监测与法律法规体系建设 ;⑥建立良好的、和谐的社会、经济和政治关系。     

农业生态经济学的内容和性质

一、农业生态经济学的内容农业经济系统和农业生态系统组成的系统国外称为“生态经济系统”(Ecolonomic system,)。农业生态经济学用农业生态经济系统这个概念把农业生态系统与农业经济系统联系起来当作一个功能单位研究,其中心是它的结构和功能。研究农业生态经济系统结构,主要是以天然生态系统和工业经济系统为参照系统,对系统的组成部分、农业生态系统与农业经济系统     

农业生态系统中的AM真菌多样性

农业生态系统复杂庞大,是由如麦田生态系统、水稻田生态系统、果园生态系统、草地生态系统、保护地生态系统等组成的一个复合生态系统。重点介绍农业生态系统中丛枝菌根(AM)和AM真菌多样性,探讨农业生态系统中调控AM真菌多样性的途径以及今后研究的动向。     

建平县农业生态系统结构总体设计的研究

农业生态系统结构的总体设计是农业生产发展的客观要求,同时,也是保证农村经济不断增长和农村生态系统良性循环的一个非常重要问题。农业生态系统边界范围较大,具有多层次、多因素、多目标、多途径等复杂性,要想深刻剖析农业生态系统结构和功能的关系,必须用系统工程的观点和方法对农业生态系统的结构进行控制和管理。本文通过对建平县农业     

农业生态系统结构指标体系及其量化方法研究

本文提出农业生态系统结构的3级指标体系及其指标内各成分的折算问题。同时结合浙江省典型农户的调查,探讨对原始数据目的旨在统一量纲和缩小指标间数最级悬殊的有效转换方法。     

农业生态系统模式的形成演替及其空间分布格局探讨

农业生态系统模式是由生物要素与非生物环境之间相互作用而构成的一个物质实体 ,它会随时间的变化而发生状态的演替或“位移” ,在空间上也会呈现一定的分布格局 ,那么引起农业生态系统形成与演替的动因是什么 ?其运行的内在机制是什么 ?是农业生态学中值得探讨的一个重要问题 ,目前也是一个较为薄弱的研究领域。农业生态系统模式时空分布与演替规律的研究可对农业生态系统的设计与构建、区域模式群的景观生态规划与布局提供重要的理论依据与实践指导。1　农业生态系统模式形成与演替　　农业生态系统模式是区域自然环境与社会经济条件共同…     

耗散结构理论与农田杂草系统控制策略初探

一、农田杂草系统控制与耗散结构理论耗散结构理论阐明了一个开放系统由混沌无序向有序态进化的过程和规律。生态系统属耗散结构已得到论证。作为农田生态系统,在开放性、非平衡性、相干性和随机涨落机制四方面,与自然生态系统相似,均满足耗散结构的构成条件,因此,农田生态系统也属耗散结构。农田杂草防除实质上是农田生态系统的调     

农业文化遗产生态系统服务的复合增益——以浙江瑞安滨海塘河台田系统为例

农业文化遗产是农村与其所处环境长期协同进化和动态适应下所形成的独特的土地利用系统和农业景观，具备丰富的景观要素。景观要素的耦合会对景观整体的生态系统服务供应产生影响。研究构建了多景观要素的“生态系统服务复合增益”理论框架，并以浙江瑞安滨海塘河台田系统为例，将其景观要素划分为农田生态系统和水域生态系统，并分别评估其景观要素生态系统服务价值、景观整体生态系统服务价值和生态系统服务复合增益价值。研究结果显示：(1)2019年浙江瑞安滨海塘河台田系统生态系统服务总价值为187.72亿元，文化服务价值最高，占总价值的91.8%;(2)农田的生态系统服务价值为6.03亿元，占总价值的3.2%,水域的生态系统服务价值为8.15亿元，占总价值的4.3%;(3)生态系统服务复合增益价值为173.54亿元，占总价值的92.5%。研究表明，农田和水域两种景观要素的耦合能提高浙江瑞安滨海塘河台田系统中食物供应、气体调节、盐碱地改良、休息游憩四种生态系统服务价值，致使其产生生态系统服务复合增益。     

基于能值分析的黑龙江垦区农业生态经济系统可持续性

运用能值理论与分析方法,采用净能值产出率、环境负荷率、能值密度、人均能值用量、能值产投比及可持续性指数、系统稳定性指数及优势度指数等重要能值指标,对黑龙江垦区2002—2011年间农业生态经济系统的能值结构作了分析。结果表明:黑龙江垦区各项指标都维持在较高水平,工业辅助能投入大幅增加,农业生态系统的产能不断提高,垦区的经济发展水平和职工生活水平得到显著改善,但由此也产生了农业生态系统可持续性下降、种植结构不合理和能源利用效率低等问题,需要在今后的发展中亟待解决。     

新型冠状病毒肺炎疫情对辽宁省食用菌产业的影响及应对措施

概述了新型冠状病毒肺炎疫情期间辽宁省食用菌产业生产和管理现状,分析了疫情对辽宁省食用菌产业产前、产中、产后的影响,指出了原辅料准备、菌种(棒)生产、养菌管理、产品销售以及人员用工、交通物流等存在的诸多问题,明确了疫情对食用菌产业结构、销售市场结构、投资市场结构主要的影响因素,提出了应对交通不畅、劳动力匮乏、资金短缺、技术缺乏的具体措施,并对辽宁省食用菌产业健康持续高质量发展提出建议。     

Measurement and calculation of carbon intensity based on ImPACT model and scenario analysis: A case of three regions of Jiangsu province

In order to find the best approach to achieving the carbon intensity reduction targets of Jiangsu province, we used an ImPACT model to undertake a scenario analysis of the economic development, population size, energy intensity, and energy consumption structure of three regions of Jiangsu province. Based on carbon intensity reduction targets of 40% and 45%, the carbon intensity in different scenarios for 2015 and 2020 were calculated in order to find the optimum emission reduction scenarios for the three regions of Jiangsu province. The research results suggest the following. Only the northern and southern regions of Jiangsu province can achieve the 40–45% reduction target for carbon intensity in 2020 in all of the scenarios. The northern regions of Jiangsu province have a minimum carbon intensity of 0.525414 tons per ten thousand yuan in the scenarios where the economic development and population size are at a medium rate of increase and the energy intensity and energy consumption structure are at a high rate of change. The middle regions of Jiangsu province have a minimum carbon intensity of 0.566539 tons per ten thousand yuan in the scenarios where the economic development is at a high rate of increase and the energy intensity and energy consumption are at a high rate of change. The southern regions of Jiangsu province have a minimum carbon intensity of 0.613281 tons per ten thousand yuan in the scenarios where the energy intensity and energy consumption structure are at a high rate of change. On the basis of these findings, this study developed relevant policies and suggestions.     

Biodemographic and Genetic Structure of Zamora Province (Spain): Insights from Surname Analysis

Located in the north-western extreme of the Iberian northern plateau with the Portugal border on the west, Zamora province is one of the current divisions of the autonomous region of Castile-Leon (Spain). According to natural boundaries and historical records, the province of Zamora can be subdivided into six different regions: Aliste, Benavente, Bajo Duero, Campos-Pan, Sanabria and Sayago. The geography of the area is configured by two major rivers: the Duero that crosses the province in a west-east direction and its affluent the Esla that crosses the province in a northwest-southeast course. In this work, we analyze both surnames of 166,349 individuals from Zamora province. The main goal of this study is to explore the differential weight of historical, demographic, geographic and sociocultural factors in shaping the bio-demographic and genetic structure of this specific population. The highest value of total consanguinity based on random isonymy is observed in Sanabria, which also has the lowest values of heteronymy and the highest intra-population a priori kinship. By contrast, Sayago exhibits the highest value of heteronymy and the lowest intra-population a priori kinship. The consanguinity values observed in Zamora are, in part, related to the population structure. Notwithstanding, the values of non-random consanguinity observed in some municipalities could be associated with particular mating behaviors that favor isonymic marriages. Finally, the results of analyses indicate that the levels of micro-differentiation in the province cannot be considered high; however, some degree of substructure could be deduced. It appears that the current population structure of Zamora has been determined not only by settlement history, geographic distance and geographic boundaries, but also, by land system distribution and population size.     

Ethnicity and biodemographic structure in the Arbëreshe of the province of Cosenza, southern Italy, in the XIX century

Cultural and environmental factors interact in determining the genetic structure of human populations. Bio-demographic investigations of ethnic minorities are able to disentangle the influences that these two components have on the evolution of the genetic structure of a population. The ethnic minority of the Arb?reshe of the province of Cosenza (Calabria, southern Italy) is analyzed in this paper and its bio-demographic structure in the early 1800s is compared with that of neighboring Italian populations. The data derive from surnames recorded in the birth registers of the 19 Arbdreshe municipalities of the province of Cosenza and in 5 non-Arb?reshe municipalities of the same province. Isonymy and repeated pairs of surnames are used to analyze the bio-demographic structure of these populations, while analysis of isonymic relationships is used to investigate the variability between populations. Higher values of marital isonymy and subdivision into subpopulations characterize the Arb?reshe populations with respect to their non-Arb?reshe neighbors. However, the high range of variability of these parameters suggests a strong influence of geographic location on the marriage pattern of each community. At the same time, cultural differences linked to group identity had a strong impact in limiting marriage exchanges between the different ethnic groups living in the province of Cosenza in the early 1800s. In fact, the analysis of isonymic relationships demonstrates that geographic location shaped kinship patterns among the Arbereshe communities, but it also shows that the non-Arb?reshe neighbors formed a clearly separate reproductive cluster.     

Biogeographical structure and affinities of the marine demersal ichthyofauna of Australia

Aim To investigate the biogeographical structure and affinities of the Australian marine demersal ichthyofauna at the scale of provinces and bathomes for the purposes of regional marine planning. Location Australia. Methods Patterns of distribution in the Australian fish fauna, at both intra‐regional and global scales, were examined using a science‐based, management framework dividing Australia’s marine biodiversity into 16 province‐level biogeographical units. Occurrences of 3734 species in eight depth‐stratified bathomes (from the coast to the mid‐continental slope) within each province were analysed to determine the structure and local affinities of their assemblages and their association with faunas of nearby regions and oceans basins. Results Strong geographic and depth‐related structure was evident. Fish assemblages in each province, and in each bathome of each province, were distinct, with the shelf‐break bathome more similar to the adjacent continental shelf bathome than to the upper slope bathome. Data based only on endemic species performed well as a surrogate of the entire dataset, yielding comparable patterns of similarity between provinces and bathomes. Tropical and temperate elements were better discriminated than elements of the Pacific and Indian oceans, with the central western province more similar to the tropical provinces (including those in the east), and the eastern province closer to southern temperate provinces. The fauna shares the closest regional affinities with those of the adjacent south‐west Pacific, western Pacific Rim, and elements of wide‐ranging Indo‐Pacific components. Elements unique to the Pacific and Indian oceans are poorly represented. Main conclusions The complex nature of Australia’s marine ichthyofauna is confirmed. A hierarchy of provinces and bathomes, used to ensure that Australia’s developing marine reserve network is both representative and comprehensive, is equally robust when based on all known Australian fish species or on only those species endemic to this continent. Latitude and depth are more important than oceanic influences on the composition of this fauna at these scales.     

Genotyping Cryptosporidium andersoni in Cattle in Shaanxi Province,Northwestern China

The present study examined the prevalence and genotypes of Cryptosporidium andersoni in cattle in Shaanxi province, China. A total of 2071 fecal samples (847 from Qinchuan cattle and 1224 from dairy cattle) were examined for the presence of Cryptosporidium oocysts, and 70 samples (3.4%) were C. andersoni-positive and those positive samples were identified by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) and the Cryptosporidium oocyst wall protein (COWP) genes. C. andersoni was the only species found in the examined cattle in this province. Fifty-seven C. andersoni isolates were characterized into 5 MLST subtypes using multilocus sequence typing analysis, including a new subtype in the native beef breed Qinchuan cattle. All of these C. andersoni isolates presented a clonal genetic structure. These findings provide new insights into the genetic structure of C. andersoni isolates in Shaanxi province and basic data of Cryptosporidium prevalence status, which in turn have implications for controlling cryptosporidiosis in this province.     

东北地区杂草稻与栽培稻的遗传多样性及籼粳分化

利用88对籼粳特异性分子标记对收集于我国东北三省的35份杂草稻和36份栽培稻遗传基础及籼粳分化进行研究,结果表明上述标记能够高效地鉴别稻属资源的籼粳属性,共检测到156个等位基因,平均有效等位基因(Na)为1.773。遗传多样性分析表明,东北地区杂草稻多样性水平略高于当地栽培稻,其中杂草稻的等位基因数(Na)、杂合度(He)、基因多样性(Hsk)以及多态性信息含量(PIC)分别为1.659、0.006、0.076和0.085,而东北栽培稻分别为1.557、0.004、0.060和0.067。遗传结构和聚类分析结果表明,东北地区杂草稻与栽培稻具有较近的亲缘关系,均存在一定程度的籼粳分化。进一步对籼粳血缘进行相对量化分析发现,杂草稻的籼型基因型频率(F_i=0.050)略高于当地栽培稻(F_i=0.043)。东北三省籼型基因型频率变化趋势为:辽宁杂草稻(0.062)辽宁栽培稻(0.058)吉林栽培稻(0.048)黑龙江杂草稻(0.041)吉林杂草稻(0.024)黑龙江栽培稻(0.020)。     

大川河鱼类区系及其群落生态结构的研究

鱼类区系及其群落生态结构,在理论和实践上都有十分重要的意义。但是,关于鱼类区系的生态结构问题,还未见详细报道。本文通过对大川河鱼类区系及其群落生态结构的分析,探讨鱼类区系及其群落生态结构的规律。     

竹红菌素产生菌的筛选与鉴定

通过多点采集、反复筛选,从野生竹黄子实体中筛选出1株产北醌类光敏色素的真菌。通过对菌株的个体形态特征、菌落形态特征进行观察,结合其显微结构特征最终鉴定为竹黄菌（Shiraia bambuscola)。     

基于EMD的河北省粮食产量波动的结构特征及其成因的分析

在分析河北省粮食产量变化的时间序列总体特征的基础之上,对河北粮食产量波动结构特征及其成因进行研究,旨在为指导河北省粮食安全生产提供科学的理论依据.综合运用EMD法、剩余法和方差分析法,对河北粮食产量波动结构特征及其成因进行研究.结果表明:在品种上,小麦和玉米两大主要粮食作物产量比重呈现递增趋势,两者之和达到了89.91%,其变动对粮食总产的变动起着举足轻重的作用;杂粮作物和稻谷所占比例较小,且呈逐年缩减趋势;小麦、玉米产量波动的方差贡献率分别为64.36%和31.72%,是河北省粮食总产波动的第一和第二主控作物;稻谷和杂粮作物由于其粮食产量基数较小对河北粮食总产波动的影响较小.在空间上,河北省粮食产量的波动值分布在0～0.35之间的地区比例约为90%,表明其强度主要处于中等水平;燕山太行山山前平原区和冀鲁豫低洼平原区粮食产量波动的方差贡献率分别为22.05%和17.82%,是河北省粮食总产波动的第一和第二主控区;辽吉西蒙东南冀北山地和后山坝上高原区的粮食产量波动对河北省粮食总产波动影响较小.研究表明综合运用EMD法、剩余法和方差分析法,对河北粮食产量波动结构特征及其成因进行研究是可行的.利用这种综合方法,提高了单独使用一种方法进行波动性分析的精度,为分析波动问题提供了新的科学的理论和方法.