中草药防治肉鸡腹水综合症的研究进展

肉鸡腹水症是遍布世界各地的一种代谢性疾病,发病率及死亡率高,对肉鸡养殖业造成了严重损失.通过查阅文献资料的方式汇总了近年用中草药防治肉鸡腹水症的研究资料,阐述了肉鸡腹水症病因及用中草药防治的研究进展,旨在探讨中草药防治本病的作用机理,为采取有效防治措施提供理论依据.     

Pb~(2+)·Cd~(2+)及其复合污染对云和雪梨树苗生理生化指标的影响

[目的]研究Pb2+、Cd2+及其复合处理对云和雪梨树苗生理生化指标的影响,为种苗生产提供参考。[方法]采用因子分析法,研究Pb2+、Cd2+及其复合污染对云和雪梨苗生理机能的影响。[结果]Pb2+、Cd2+污染抑制树苗的生长,影响梨苗叶绿素的含量,抑制超氧化物歧化酶(SOD)活性,提高梨苗丙二醛(MDA)和可溶性蛋白质含量,刺激谷胱甘肽(GSH)合成,Pb2+、Cd2+之间的相互作用复杂。[结论]Pb2+、Cd2+污染云和雪梨苗,抑制叶绿素的合成,增强超养阴离子自由基(O2-.)对植株的毒害性,使膜脂过氧化损伤程度高,受重金属污染植株启动保护酶系统,以增强植株的抗氧化性。Pb2+、Cd2+相互作用机制复杂。     

地膜覆盖栽培对小京生花生土壤温湿度的调控及其生物学效应

2002-2003年的试验表明,地膜覆盖栽培对小京生花生的土壤调温、调湿效应十分显著,在生育前期能提高土壤温度,夏季降低土壤温度,连续降雨天气能降低土壤湿度,干旱天气能提高土壤湿度,从而使小京生花生生育期提前,地上、地下部分生长良好,产量显著提高。实验结果为进一步推广和扩大地膜栽培提供依据。     

Contrasting recreational and commercial fishing: Searching for common issues to promote unified conservation of fisheries resources and aquatic environments

Commercial fishing has repeatedly been identified as a major causal factor for global declines in fish stocks. Recently, recreational fisheries have also been considered as having the potential to contribute to fisheries declines. Here, we take a global focus, contrasting the characteristics of commercial and recreational fisheries relevant to conservation and sustainability of exploited fishes in both marine and freshwater environments. We provide evidence to support our assertion that the same issues that have led to global fisheries concerns regarding commercial fishing can have equivalent, and in some cases, magnified effects in recreational fisheries. Contrasts revealed that the issues of bycatch and catch-and-release, fisheries-induced selection, trophic changes, habitat degradation, gear technology, fishing effort, and production regimes are remarkably similar among fishery sectors. In recognition of this conclusion, we present a new vision for recreational fishing that positions it on the same scale and urgency as commercial fisheries. Efforts to manage and conserve fisheries must recognise that issues and threats are similar in these fundamentally and philosophically different fisheries, as may be the solutions. Failure to recognise the similarities will further polarise these sectors and retard efforts to conserve aquatic resources. Fishing activity of any kind, whether commercial or recreational, has the potential to affect negatively fish and fisheries, as well as aquatic environments.     

Sustainable management of wildlife habitat and risk of extinction

Whether land management planning provides for sufficient habitat to sustain viable populations of indigenous wildlife is one of the greatest challenges confronting resource managers. Analyses of the effects of land management on natural resources often rely on qualitative assessments that focus on single species to reflect the risk of wildlife extinction across a planning area. We propose a conceptual framework for sustainable management of wildlife habitat that explicitly acknowledges the greater risk of an extinction event when considering the viability of multiple species, e.g., an indigenous vertebrate fauna. This concept is based on the principle that the likelihood of at least one event (i.e., species extinction) is the joint probability of the extinction probabilities of individual species, assuming independence among species’ responses to disturbance. We present an ecological rationale to support the view that, at a spatial scale of 10⁴-10⁶ ha (i.e., planning area) and a temporal scale of 10² years (i.e., planning horizon), wildlife species operating at varying ecological scales respond relatively independently to disturbances typically associated with land management. We use a hypothetical scenario of a wildlife viability assessment and Monte Carlo simulation to demonstrate that the probability of ‘any extinction’ is consistently higher than the probability of the ‘single most likely’ extinction, and that the difference between these values increases as more disturbance-sensitive species (i.e., species at risk) are analyzed. We conclude that risk assessments that rely upon the most sensitive single species may substantially underestimate the risk of wildlife extinction across a planning area. Furthermore, the selection of a planning alternative based on relative threat of local extinction of wildlife populations can vary depending on which paradigm is used to estimate risk to viability across the planning area.     

紫外线(UV)-B增强对植物的影响研究

对大气中臭氧层变薄的现状及紫外线划分的方法进行了介绍。综述了国内外近几十年有关UV-B辐射对植物影响的研究现状,讨论了增强的UV-B辐射对植物生长及形态结构,植物生理生化代谢,UV-B吸收物质,植物遗传物质及某些基因表达,植物细胞膜及抗氧化系统,环境多因子相互作用对植物和种群及生态系统的影响,并对该研究领域今后的研究方向进行了展望。     

植物对土壤微生物多样性的影响研究进展

土壤微生物是植物-土壤系统中比较活跃的组成成分,土壤微生物多样性代表着微生物群落的稳定性,对植被的生长发育和群落结构的演替具有重要作用。本文通过植物类型、植物多样性、植物不同生长发育阶段、同一植物不同基因型、植物根系分泌物和外来植物入侵对土壤微生物多样性的影响分析,探讨植物和土壤微生物多样性之间的内在联系,为植物保护和农业可持续发展研究提供参考。     

无公害平菇代料栽培标准化生产技术

本文提出了平菇无公害生产技术及栽培措施,包括母种、原种及栽培种、栽培袋的无公害生产技术,出菇管理技术,病虫害的物理防治与生物防治,产品采收要求,开发的技术完全符合国家相关无公害农产品标准。     

大樱桃根癌病的发生与防治试验

近年沂水县大樱桃根癌病危害曰趋严重，作者对大樱桃根癌病的发生情况，以及土壤类型、砧木种类及管理水平等对根癌病的影响进行了系统调查，基本摸清大樱桃根癌病的发病规律。药剂试验结果表明，地表上切除癌瘤后涂药，50倍生物菌K84液、10倍10％杀菌优＋渗透剂、400单位农用链霉素＋渗透剂的治愈率达94％～100％，复发率0—3％，涂药后4～5d病疤于枯；根颈处切除根瘤涂药后的防治效果仍以上述3种药剂的控制效果比较好，且明显好于不切除根瘤、药剂灌根的防治结果。     

Effects of deforestation on phosphorus pools in mountain soils of the Alay Range, Khyrgyzia

 The amount, quality and turnover of soil P is heavily influenced by changes in soil management. The objective of this study was to investigate the effects of deforestation and pasture establishment on the concentrations, forms and turnover rate of soil P in mountain soils of the Alay Range, Khyrgyzia. A sequential extraction was applied to distinguish soil P pools. We used particle-size fractionation to follow the dynamics of different P pools in soils under forest and pasture and ³¹P-NMR spectroscopy to investigate the structure of alkali-soluble P forms. In the A horizons of the forest soils, total soil P concentration was 1093 mg kg^–1, organic P (P_o) representing 46% of the total P. Deforestation followed by pasture establishment not only increased significantly (P<0.01) the total P concentration (1560 mg kg^–1) but also the contribution of P_o to total P was increased by 17%. Pasture soils had significantly higher P pools than forest soils except highly labile inorganic P (P_i NaHCO₃) and primary P_i (P_i HCl_dil). Both in forest and pasture soils stable P increased with decreasing particle size (coarse sand 50%, clay 80% of total P) and primary P decreased with decreasing particle size. Phosphate monoesters and diesters represented 80% of P identified by ³¹P NMR. Low monoester to diester ratios in the alkali extracts of forest and pasture soils indicate low microbial activity. This is consistent with high C/P_o ratios and high stable P_o concentrations in the fine earth of forest and pasture. Received: 10 March 1999