基于PSR模型的生态文明示范区生态安全评价及其障碍诊断

为了探究生态文明示范区生态安全的变化趋势与影响因素,基于PSR构建区域生态安全评价指标体系,运用熵权法对江西省生态文明先行示范区2009-2018年生态安全状况进行评价,结合障碍模型分析了其生态安全障碍因素。结果表明:(1)在2009-2018年江西省各地市生态安全水平总体有所提升,但生态安全等级各地差距较大;(2)江西省生态安全障碍度排序结果为响应因素>压力因素>状态因素,且受到城镇建设用地面积比重、生态环境耗水量、城镇化水平、第一产业占GDP比重以及单位土地面积农药使用量的综合影响;(3)江西省生态安全划分为生态经济发展协调区、生态经济改善区和生态安全脆弱区;(4)应从存量用地再开发、推动区域产业高质量发展和强化生态环境政策响应方面构建生态安全治理体系。可见,生态文明示范区生态安全等级介于临界安全等级(Ⅱ)较多,距离基本安全等级(Ⅲ)状态仍有较大差距,而通过分析生态安全空间与诊断影响因素可为提升生态安全水平提供理论支持。     

杧果果实生长发育规律的研究

紫花着果后５０～６０天是果实生长的高峰期。随后生长速度减慢，果肉颜色从白转为淡黄，果核逐渐硬化。生长发育过程中有机物的变化主要是淀粉。着果后约６０天淀粉积累明显加快，９０天含量达最高（为５．６５％），以后明显下降。成熟期可溶性糖含量随淀粉下降而增高。有机酸含量亦在着果后６０天最高（为２．６２％），以后下降。结果表明，着果后６０天及９０天分别是果果实生长发育过程的生理转折期。     

Processes affecting genetic structure and conservation: a case study of wild and cultivated <Emphasis Type="Italic">Brassica rapa</Emphasis>

When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.     

四川龙溪-虹口常绿阔叶林凋落物与土壤碳、氮、磷化学计量特征分析

以龙溪虹口海拔873～2 211 m的常绿阔叶林为研究对象,通过野外采集和室内分析,探讨了常绿阔叶林土壤与凋落物有机碳(C)、氮(N)、磷(P)生态化学计量特征对海拔、土层和森林类型的响应特征。结果表明:①随着海拔的上升,不同土层的土壤和凋落物有机碳、氮、磷含量均呈现出增加的趋势;土壤和凋落物有机碳、氮、磷含量与海拔呈极显著正相关关系。②土层厚度与土壤N/P和C/P显著负相关,海拔和森林类型与凋落物C/P显著负相关,森林类型仅与凋落物N/P显著负相关。③研究区内土壤和凋落物C/N高于中国森林系统土壤和凋落物C/N,表明凋落物分解速度较慢,矿化和腐殖化程度较低,土壤硝酸盐淋溶风险较低,养分贮藏能力较好。土壤氮、磷含量与凋落物C/N和C/P显著负相关,说明该地区凋落物分解受土壤氮、磷元素共同的限制。研究结果可为探讨森林土壤养分供应和限制因素以及研究区域内土壤质量评价和森林管护提供科学依据。     

Assessing replacement cost of conservation areas: How does habitat loss influence priorities?

Replacement cost refers to the loss incurred if the ideal set of conservation areas cannot be protected due to compulsory inclusion or exclusion of some area candidates. This cost can be defined either in terms of loss of conservation value or in terms of extra acquisition cost, and it has a clear mathematical definition as a difference between the value of the unconstrained optimal solution and a constrained suboptimal solution. In this work we for the first time show how replacement cost can be calculated in the context of sequential reserve selection, where a reserve network is developed over a longer time period and ongoing habitat loss influences retention and availability of sites. In case of site exclusion, a question that can be asked is, “if a site belonging to the ideal (optimal) solution cannot be obtained, what expected loss in reserve network value does this entail by the end of the planning period given that the rest of the solution is re-organized in the most advantageous manner?” Heuristically, the proposed method achieves the ambit of combining irreplaceability and vulnerability into one score of site importance. We applied replacement cost analysis to conservation prioritization for wood-inhabiting fungi in Norway, identifying factors that influence replacement cost and urgency of site acquisition. Among other things we find that the reliability of loss rate information is important, because the optimal site acquisition order may be strongly influenced by underestimated loss rates.     

Setting conservation targets under budgetary constraints

Target-based spatial prioritization is the default approach in conservation resource allocation. Here, we clarify a poorly known feature of target-based spatial prioritization that may lead to an unbalanced allocation of resources between species or other biodiversity features. Highest per-species resources will be allocated to species occurring in costly and otherwise species-poor locations, whereas smallest per-species resources will be allocated to species that occur in species-rich locations at low-cost areas. Uncertainty in information about processes determining distributions of biodiversity features may lead to uncertainty in target setting. This can be a problem if unnecessarily high targets emerge to consume excessive resources thus detracting from other conservation action. Difficulties might be encountered in particular when there are many features, targets are given simultaneously to multiple different types of biodiversity features, or components of features, or when there are interactions or correlations between features. Consequently, we recommend that the costs of targets for individual features could be evaluated to screen for such targets that consume a disproportionate fraction of available resources. Costs of targets can be evaluated by a variant of the replacement cost technique. We also find that commonly used reserve selection methods, minimum set coverage, maximum coverage, and utility maximization differ significantly in how they treat targets and their costs.     

Administrative regions in conservation: Balancing local priorities with regional to global preferences in spatial planning

Site selection, reserve selection, and spatial conservation prioritization are terms that have been used for various algorithms and methods for the spatial allocation of conservation resources. Many of these methods start from the setting of targets or weights for different conservation features. Almost always there is only one set of targets or weights, thus implicitly assuming that priorities stay the same through the entire planning region. However, priorities for biodiversity governance could vary between regions. For example, priorities inside countries could be different from global priorities. Inside a country, different stakeholders could hold different priorities. Thus, priorities could vary between sub-regions while ecological processes, such as connectivity, cross borders without regard to administrative boundaries. Here we describe how it is possible to account for conservation priorities that vary between administrative sub-regions in conservation prioritization. We illustrate how assumptions about selection methods and feature weights can significantly influence the outcome mapping of conservation priority. We also show how placing high emphasis on local considerations reduces the cost-efficiency of the global conservation outcome. Analyses proposed here will be made publicly available in software (Zonation) capable for large-scale high-resolution conservation prioritization.     

甘薯辐射后代酯酶同功酶的测定和分析(简报)

同功酶是生物体内结构和物理性质不同而执行功能相同的酶。同功酶电泳在作物的分类、鉴定及起源研究中有重要意义。在甘薯作物方面,Kokubu,T.等(1978)对日本国内甘薯品种,国外引进甘薯品种,甘薯属中近缘野生种的种间杂种等进行了酯酶同功酶和过氧化物酶同功酶的测定,比较了它们的差异。薛启汉等(1986)对甘薯与四倍体野生种海滨野牵牛的种间杂种的过氧化物酶同功酶进行测定,观察了变异;1988年薛等又对23份甘薯属中不同倍性野生种和栽培种进行了过氧化物酶同功酶的酶谱分析。本文则以甘薯品种的辐射材料进行酯酶同功酶的研究。     

Spatiotemporal dynamics and risk factors of rotavirus A circulation in backyard pig farms in a Philippine setting

Rotavirus A is one of the leading etiological agents of porcine gastroenteritis, a condition which results to stunted growth among piglets. Moreover, there is increasing evidence for zoonosis of rotavirus A (RVA), which is also the principal cause of diarrhea in children. In the absence of rigorous animal health monitoring in Philippine backyard farms, there is therefore a strong need for RVA surveillance. In this study, 30 randomly selected backyard farms were subjected to surveillance for RVA for 12 months. Results show that RVA detection at a monthly farm-level rate ranged from 0 to 52%, with an overall average of 23%. RVA had higher detection rates in adult pigs compared to young piglets and was most prevalent in non-diarrheic stools, indicating asymptomatic circulation of the virus. Spatiotemporal analysis demonstrated that the viral circulation exhibits a seasonal pattern that peaks and forms geographical clusters during the cooler months of the year, suggesting farm-to-farm transmission. Risk factor analysis identified specific farm conditions that increase the likelihood of RVA circulation: presence of gilts, larger herd size, presence of other animals, and abiotic factors such as low relative humidity and low altitude. The same analysis also revealed three major management practices that can help reduce the pressure of infection in these farms: sanitation and waste disposal, animal grouping, and diet. This new perspective on porcine RVA circulation will benefit the underprivileged backyard farmers and help empower them to protect both animal and public health.