护坦与丁坝在林区沿河公路防护中的应用

研究分析了丁坝和护坦在沿河林区公路路基防护中的作用、防护原理、设置方法、应用条件和有效性问题。     

Relating Kirtland's warbler population to changing landscape composition and structure

The population of male Kirtland's warbler (Dendroica kirtlandii) in the breeding season has averaged 206 from 1971 to 1987. The Kirtland's warbler occupies dense jack pine (Pinus banksiana) barrens from 5 to 23 years old and from 1.4 to 5.0 m high, formerly of wildfire origin. In 1984, 73% of the males censused were found in habitat naturally regenerated from wildfire or prescribed burning. The rest were in plantations (11%) or in harvested, unburned jack pine stands stocked by natural regeneration (16%). Twenty-two percent (630 of 2,886) of the Kirtland's warbler males counted in the annual censuses from 1971 through 1984 were found in 26 stands that were unburned and naturally regenerated following harvest. From 1982 to 1987, suitable regenerating areas were barely sufficient to replace currently occupied maturing stands, so population growth was impeded. Ecosystems of suitable size and regeneration characteristics (wildfire and plantation) doubled in area by 1989. In response, the population of Kirtland's warblers increased from 167 to 398 males between 1987 and 1992, but they withdrew almost entirely from the unburned, unplanted barrens by 1989 when the area of more suitable regeneration types increased. Minimum (368 males) and maximum (542 males) population estimates for 1996 were calculated based on 1984 average density (1.9 males per 40 ha) and peak population in burns (2.8 males per 40 ha).     

浅谈我省地方畜禽品种资源保护及开发利用

近年来，我省先后从国内外引进了20多个鸡种，10多个牛种、羊种和猪种等，因其高效而占领了我省市场。同时存在着盲目引种，品种多乱、杂等问题。伴随着少数高产畜禽品种的普及推广，使各地固有的许多品种资源迅速减少或消失。因此，针对陕西畜禽品种资源的现状问题，并结合近年来畜牧业生产中的实际状况，特就如何搞好地方畜禽品种资源的保护及开发利用提出建议与对策。     

虚拟仪器技术及其在距离保护中的

介绍了虚拟仪器的发展过程以及虚拟仪器的软件与硬件的基本构成原理,设计了一套虚拟仪器系统，并在此基础上对距离保护进行了仿真实验。认为虚拟仪器在电力系统具有广泛的应用前景，是今后一段时间的发展方向。     

高等级公路生物护坡工程模式设计

根据高等级公路边坡的土体特性 ,将边坡分成硬质材料覆盖坡面、松软基质坡面、紧实基质坡面三种类型 ,按照不同类型边坡的土壤组成结构、坡角大小及物种选择的理论依据和生物护坡工程实践 ,提出了各类型的边坡应采取的绿化施工手段及物种选择与组合搭配的一般规律     

澳门海岸防护林多树种配置造林效果分析

对澳门凼仔岛海岸山地防护林造林地 (8年生 )进行调查 ,分析了林分保存率、林分生长量、各树种平均胸径、平均树高、林分土壤肥力和林分植被变化情况。认为海岸山地防护林营造多树种阔叶混交林是一种值得研究推广的林分改造模式     

STUDY ON THE EFFECT OF CLIMATE CHANGE ON FOREST FIRE IN HEILONGJIANG PROVINCE

GENERALCoNDlTloNABoUTCLI-MATECHANGEINHElLoNGJIANGPRoVINCEDtlrlngthepasscdll)()}ears(l88l-l`)8(j)ors().tllctcndenc}'ofmcanairtc111pcraturcincrcasct\ithfluctuationcl11ergcdin\ariousrcglonsofHcllonViangproxincc.Airtcmpcra-turcinl98()s-rcachcdtl1emaxil11un1uithinthcpasscdll)()y'cars.Thisphcl1ol11enonaccordcd``iththctcndenc}'ofglobalclil11ate\"ar1ni11g.Thel11eanairtc111peralurcil1tl1creccl1tl()}car(l()8()-l()8`))incrcascdb}l).6"Cascom-pal-cd\`ltl1tl1atll1tl1clbrl11er3())'carsacc…     

制糖废水处理方法研究进展

制糖废水是一种高浓度的有机废水 ,如何高效处理是环境工程研究的一个重点。本文就其国外最新的研究成果进行了总结     

浅谈林地资源保护管理与生态林业建设

论述了建德市林地资源保护和生态林业建设现状以及他们间的相互关系，并提出要搞好生态林业建设必须建立林地资源保护管理体系，对林地资源要实行总体规划，合理使用。     

黑龙江省植物物种及其保护概况

黑龙江省共有三个植物区,植物区系成分比较复杂,有多种多样的生态系统,植物物种非常丰富。目前,黑龙江省共有维管束植物185科92属2503种,种类较多的科依次是:菊科(Compositae)、禾本科(Gramineae)、莎草科(Cyperaceae)、蔷薇科(Rosaceae)等。但由于生境的破坏,我们黑龙江省每年都有一定数量的植物灭绝或处于灭绝的边缘,这要求我们对它们加以保护,主要方法有:就地保护、迁地保护等,不但对物种进行保护,更重要的是保护其生态系统。