鸡公山自然保护区森林生态系统服务功能及其价值初步研究   总被引：12，自引：1，他引：12  

茹永强  哈登龙  熊林春  戴慧堂  乔国壮  陈锋 《河南农业大学学报》2004,38(2):199-202

从生态系统服务功能的概念入手,根据调查和研究,采用替代工程、市场价值等方法,从2个方面评价了鸡公山自然保护区森林生态系统服务功能的价值.结果表明,面积3000hm2的鸡公山自然保护区森林生态系统的生态服务功能价值70548.6万元·a-1,其中涵养水源价值8593.9万元·a-1,净化水质价值1265.3万元·a-1,保持土壤价值57754.1万元·a-1,固碳制氧价值2114.2万元·a-1,净化环境价值(吸收SO2量)26.1万元·a-1,游憩价值550万元·a-1,林产品价值245万元·a-1.  相似文献   

Modeling the Exchanges of Energy, Water, and Carbon Between Continents and the Atmosphere   总被引：19，自引：0，他引：19  

PJ Sellers  RE Dickinson  DA Randall  AK Betts  FG Hall  JA Berry  GJ Collatz  AS Denning  HA Mooney  CA Nobre  N Sato  CB Field  A Henderson-Sellers 《Science (New York, N.Y.)》1997,275(5299):502-509

Atmospheric general circulation models used for climate simulation and weather forecasting require the fluxes of radiation, heat, water vapor, and momentum across the land-atmosphere interface to be specified. These fluxes are calculated by submodels called land surface parameterizations. Over the last 20 years, these parameterizations have evolved from simple, unrealistic schemes into credible representations of the global soil-vegetation-atmosphere transfer system as advances in plant physiological and hydrological research, advances in satellite data interpretation, and the results of large-scale field experiments have been exploited. Some modern schemes incorporate biogeochemical and ecological knowledge and, when coupled with advanced climate and ocean models, will be capable of modeling the biological and physical responses of the Earth system to global change, for example, increasing atmospheric carbon dioxide.  相似文献   

The persistence of foot-and-mouth disease virus on wool   总被引：1，自引：0，他引：1  

KA McCOLL  HA WESTBURY  RP KITCHING†  VM LEWIS 《Australian veterinary journal》1995,72(8):286-292

SUMMARY Five Suffolk sheep, held in a high-security isolation room, were exposed for 2 hours to the aerosol of 3 mature pigs that had been infected with foot-and-mouth disease virus (FMDV), strain O₁-BFS. The fleeces of 3 of the sheep were contaminated with FMDV at 2 days post exposure (dpe), while at 5 dpe the fleeces of all 5 sheep were more extensively, and more heavily, contaminated. The persistence of FMDV on contaminated wool was examined in vitro using multiple 0.5 g samples of Merino wool that were each contaminated with one of 3 strains of FMDV in tissue-culture medium: O₁-BFS, O-Morocco (O-MOR 9/91) or an Asia 1 strain (TAI 1/90). Wool samples were held at either 4°C, 18°C or 37°C, and decay curves were established for each virus at each temperature. These curves predicted that O₁-BFS, O-MOR 9/91 and TAI 1/90 would fall below detect-able levels at 72, 70 and 48 days post contamination (pc), respectively, for wool stored at 4°C; at 11, 12 and 12 days pc, respectively, for wool stored at 18°C; and at 57, 68 and 33 hours pc, respectively, for wool stored at 37°C. For wool contaminated with O₁-BFS-infected sheep faeces, urine or blood, or with O₁-BFS-infected cattle saliva, decay curves predicted virus to persist for 5 to 11 days pc at 18°C. We demonstrated that the simulated scouring of FMDV-contaminated wool at 60° to 70°C would usually reduce virus to below detectable levels. The detergent component of the scouring process had little, if any, antiviral activity, and scouring at 20°C or 50°C had limited impact on FMDV titres . We recommend that either (1) simple storage of FMDV-contaminated wool for 4 weeks at temperatures of 18°C or higher, or (2) scouring of contaminated wool at 60° to 70°C would be sufficient to remove the threat of FMDV-contaminated wool being infectious to other animals .  相似文献   

Fungal Infection and Mechanical Wounding Induce Disease Resistance in Scots Pine     

Paal Krokene  Halvor Solheim  Bo Långström 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(6):537-541

Scots pine trees (Pinus sylvestris) recovering from a 90–100% defoliation 2–3 years previously were pretreated with small mechanical wounds or inoculations with the blue-stain fungi Leptographium wingfieldii and Ophiostoma canum. Pretreated trees were less susceptible to a subsequent massive inoculation with L. wingfieldii than untreated control trees, which were extensively colonised by the mass-inoculation. A low pretreatment dosage of L. wingfieldii was somewhat more effective in inducing disease resistance than a higher dosage. Pretreatment with L. wingfieldii, O. canum, and mechanical wounding were about equally effective inducers of resistance in Scots pine, even though L. wingfieldii is known to produce much more extensive phloem necrosis than the other pretreatments. Thus, the strength of the induced resistance response did not depend on the amount of host tissues that was destroyed by the pretreatment. Previously, induced disease resistance has been demonstrated in Norway spruce (Picea abies), and the present study shows that similar responses can be activated in Scots pine.  相似文献   

通辽市果树调查报告     

宝金山  刘臣 《内蒙古林业科技》2000,(2):37-40

通辽市现有果树总面积１．２４２９万ｈｍ＾２,已结果的占５５％,以苹果和梨占绝对优势。在树种和品种结构及管理上,都存在一些问题,本文对此进行阐述,提出了改进意见。  相似文献   

无尾鸡骨骼发育关键信号通路研究进展     

齐旺梅  徐斯日古楞  哈登楚日亚  刘斌  胡斯乐  孙燕勇  张文广 《中国畜牧兽医》2021,48(6):2011-2019

骨骼系统对机体的生命活动至关重要，它为生物体提供了造血微环境、机械支撑、保护脏器等功能，同时也是钙和其他矿物质等的储存库。家鸡尾骨的表型多样性是研究骨骼系统发育及形成机制的良好资源。Notch、Wnt信号通路的靶基因及其相互作用可以形成周期性表达的特点，是调节体节形成及尾部骨骼终止延伸的分子通路。为了解无尾鸡骨骼发育终止的分子机制，作者分别总结了骨骼发育、无尾鸡骨骼研究进展，并重点讨论影响无尾性状的关键信号通路Notch、Wnt及其在无尾鸡研究中的进展。但是，受体和配体之间相互作用的精确调节以及信号通路中的核心元素仍不清楚，需要通过更多的功能基因组和蛋白质组等方法进行深入研究。  相似文献   

Altered light conditions following thinning affect xylem structure and potential hydraulic conductivity of Norway spruce shoots     

Roman Gebauer  Daniel Volařík  Josef Urban  Isabella Børja  Nina Elisabeth Nagy  Toril Drabløs Eldhuset  Paal Krokene 《European Journal of Forest Research》2014,133(1):111-120

Trees must respond to many environmental factors during their development, and light is one of the main stimuli regulating tree growth. Thinning of forest stands by selective tree removal is a common tool in forest management that increases light intensity. However, morphological and anatomical adaptations of individual shoots to the new environmental conditions created by thinning are still poorly understood. In this study, we evaluated shoot morphology (shoot length, needle number, projected leaf area) and anatomy (tracheid lumen area, tracheid number, tracheid dimensions, xylem area, potential hydraulic conductivity) in three Norway spruce (Picea abies/L./Karst.) families exposed to different thinning regimes. We compared shoot characteristics of upper-canopy (i.e. sun-exposed) and lower-canopy (i.e. shaded) current-year shoots in a control plot and a plot thinned to 50 % stand density the previous year. One tree per family was chosen in each treatment, and five shoots were taken per canopy position. We found that upper-canopy shoots in both plots had higher values than lower-canopy shoots for all studied parameters, except lumen roundness and tracheid frequency (i.e. tracheid number per xylem area). Thinning had little effect on shoot morphology and anatomy 1 year after thinning, except for small but significant changes in tracheid dimensions. Needles were more sensitive to altered light conditions, as projected leaf area of shoot, needle number and leaf hydraulic conductivity changed after thinning. Differences between upper- and lower-canopy shoots did not seem to be influenced by thinning and were almost the same in both plots. Our results suggest that lower-canopy shoots require several years to modify their morphology and anatomy to new light conditions following thinning. The slow light adaptation of the lower canopy may be of practical importance in forest management: thinned stands may be predisposed to drought stress because newly exposed shoots experience increased illumination and transpiration after thinning.  相似文献   

抛物线沙丘形态特征与土壤含水量和紧实度的关系研究     

杜会石  哈斯 《甘肃农业科技》2014,(12):17-20

以库布齐沙漠南缘典型抛物线沙丘为研究对象,通过对沙丘土壤水分含量与紧实度的测量,分析了沙丘形态特征与土壤水分含量、紧实度的关系。结果表明,沙丘臂间平地水分含量与其周围本底值相似,高于沙丘其它地貌部位。沙丘土壤水分含量高的区域,紧实度较大,抗侵蚀能力较强。沙丘土壤水分含量、紧实度等物理性状特征也影响植被的发育与分布。  相似文献   

A Case of Gastric Adenocarcinoma in a Shih Tzu Dog: Successful Treatment of Early Gastric Cancer     

Hee-Chun LEE  Ji-Hyun KIM  Cho-Hee JEE  Jae-Hoon LEE  Jong-Hyun MOON  Na-Hyun KIM  Jung-Hyang SUR  Kyu-Woan CHO  Byeong-Teck KANG  Jeongim HA  Dong-In JUNG 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(7):1033-1038

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卵泡生长发育及其调控的研究进展     

舒建洪  哈利  石玉强 《西北农林科技大学学报(自然科学版)》2004,32(6):49-53

综述了卵泡生长发育的动态模式,即卵泡经原始卵泡、初级卵泡、次级卵泡和窦腔卵泡发育至排卵卵泡的过程,着重阐述了卵泡生长发育过程中的调控机制,为进一步研究卵泡的生长、发育和排卵机制提供了理论基础。  相似文献