青海天然草地属性及适宜性利用对策的探讨

天然草地在青海经济可持续发展和环境保护中占有重要地位,文章分析讨论了青海天然草地的属性及利用 现状,根据利用中存在的主要问题,有针对性地提出了青海天然草地适宜性利用对策,为永续利用草地资源提供参考。     

《家禽屠宰检疫规程》中有关问题分析

《家禽屠宰检疫规程》在规范家禽的屠宰检疫,加强家禽产品的检疫活动管理,保障动物源食品安全方面发挥了重要作用。本文概述了《家禽屠宰检疫规程》关于家禽屠宰场所定义、规程适用动物、检疫对象、检疫合格标准的判定等方面存在的问题,特别是针对家禽产品入库贮藏后才出厂如何出具检疫合格证明,提出可采取贮藏后继续调运或分销的检疫方式出具检疫证明这一解决方案。这提示在今后工作中扩大屠宰检疫的适用范围及检疫对象,进一步修订和完善屠宰检疫规程,提升屠宰检疫技术水平。     

盐碱地开沟躲盐种植优良牧草的研究

1　前言我市黄灌区是重要的粮食基地 ,但是由于土地利用不合理 ,排灌渠道不配套 ,有灌无排 ,使地下水位急剧抬高。再加上地质构造等原因 ,地下径流不畅及气候干燥等因素的影响 ,导致地下水及含水层中盐分不断向上运移 ,并积累于土壤表层 ,从而造成土壤盐渍化逐年加剧。据包头市土右、郊区农业区划资料介绍 ,全市现有盐碱地面积为 1 5 2 3万ｈｍ2 ,其中中度以上面积为 8 1 9万ｈｍ2 。除少部分种植葵花等经济作物外 ,大部分均因抓不住苗荒芜闲置。据市计委、土右旗、郊区规划 ,全市要开发 3 3多万ｈｍ2 盐碱地 ,重点是在黄灌区的盐渍地 ,…     

高产高淀粉玉米新品种郑单21适宜播期的研究

通过不同播期对郑单21生长发育及产量的影响研究,在河南省夏播条件下,郑单21的适宜播期为6月15日前。6月15日前播种的叶面积系数最大值高,5月26日播种的成熟期叶面积系数下降到1.891,6月5~15日播种的郑单21表现为大喇叭口到抽雄期干物质积累相对量最低,抽雄到成熟干物质积累量最高。因此,郑单21的适宜播期在6月15日前,但不宜过早。     

林木种苗基地规划设计若干问题的探讨

通过对林木种苗基地规划设计中产品方案设计、生产规模设计、生产工艺设计、基地区划设计四个方面的研究探讨,总结出林木种苗基地规划设计中应遵循的最基本的设计思路。     

黄土半干旱区集水造林条件下林木生长适宜的土壤水分环境

2000年在山西方山，采用LI－6200光合测定系统和LI－1600稳态气孔仪，对不同集水措施试验地的刺槐、侧柏和苹果的生理指标进行了实地观测，并辅以相同树种实地盆栽苗木水分胁迫条件下的林木生理指标观测，研究了林木净光合速率、羧化效率、水分利用效率与土壤含水量的定量关系。结果表明：维持刺槐、侧柏和苹果净光合作用的最佳土壤含水量分别为17.13%、15.9%和16.11%，三树种维持叶片水分利用效率的最佳土壤含水量依次为13.23%、10.66%和12.38%；羧化效率最高时的土壤含水量临界值依次为15.7%、15.5%和15.8%；土壤水合补偿点分别为4.55%、3.91%和4.49%。上述三树种蒸腾速率所适宜的土壤含水量分别为18.82%、19.70%和16.33%。根据集水造林的基本构思，可选取维持最佳叶片水分利用效率的土壤含水量临界值作为集水造林林木密度调控的土壤水分阈值和林木需水量的低限计算条件。这一指标可量化为刺槐10％－13％，苹果10％－12.5%，侧柏9.5%-11%。     

红壳竹适生环境调查与分析

红壳竹为我国优良的笋、材两用竹种，有着比较广泛的适应性，它集中分布在安徽东南部和浙江西北部，其中广德县是其中心产区。通过对广德县现有红壳竹林的分布及其不同生境中成林和新造竹林的生长表现以及林分质量的调查分析，初步得出红壳竹在其适宜的气候区内，地形、坡向、不同母岩或母质所发育的土壤对其生长发育影响很大，其生长环境可以划成3种类型，即适宜生长环境、一般生长环境、不适生长环境，从而为自然条件大体相同地区扩大栽培提供参考依据。     

Post-fire habitat restoration of sables during winter season in northern slope of the Great Xing＇an Mountains

Habitat loss and fragmentation have been associated with the decline of endangered species. In 1987, a catastrophic fire in the northern Great Hing＇an Mountains of China, where the main habitat of sables （Martes zibellina） is located, aggravated the loss and fragmentation of the forest landscape. Due to restricted distribution and low population density, sables were listed in the national first-grade protected species in China. The objective of this paper was to identify to what extent the habitat of sables had been restored 13 years after the fire. Based on the behavioral data, which came from field survey information by radio-tracking, GPS （Global Positioning System） and forest inventory data, suitability habitat maps were derived using the Ecological Niche Suitability Model （ENSM）. In addition, the habitat structure was analyzed with selected landscape indices. Although forest cover mostly had been restored by 2000, the results indicated that, compared to the pre-fire situation, the areas of suitable habitat had been reduced significantly, especially those of less suitable, marginally suitable and moderately suitable designation. Fragmentation was aggravated, and suitable patches were found to be further isolated with the exception of those in most suitable areas. The ratio of the patch perimeter to area in unsuitable, moderately suitable and suitable areas decreased, while the ratios within other suitability types increased. Moreover, the percentage of soft boundaries decreased slightly, which can influence the redistribution of sables. The results above indicated that the suitable habitat had deteriorated, and the restoration of the sables＇ habitat remained to be done.     

WATER CUTTING OF CHINESE ROSE-BETTY PRIOR

BettyPriorinrosegenus,rosebolyis-onevarietyofFlonbondaROse.ItisoneOfmodernChineserose,withcoldresistanceandagmnstpestcharactenshcsChineserosecuttase1soutOfquestionintemPeratezoneandtothe6outhoftethperat6zone,butthereexistmanyqueshonsinHarbnareawhichbelongstonortherntemperat6zonebecauseofshortergrOwingseasonandlowerairtemperatUreinautUmnandwintertmaincuttageseasonsof8ettyPnor).Theexpen-mentonwatercuthngPropagahonofBettyPnorwasconductedlnordertointroducethesspeciesintoHarbin.MThan^LSAun…     

Oxygen uptake in the Antarctic teleost Pagothenia borchgrevinki. Limitations imposed by X-cell gill disease

Fish in a population of Pagothenia borchgrevinki in McMurdo Sound, Antarctica, are affected by a gill disease (X-cell disease) which causes tissue hyperplasia that results in a decreased gill surface area and an increased water/blood diffusion distance. P. borchgrevinki acquires 95% of its oxygen via the gills, but damage to the gills by X-cell disease did not affect this function. There was no compensatory shift to cutaneous respiration. X-cell disease reduced the ability for oxygen uptake at low ambient P_{O 2} and the decreased uptake was related to the extent of the disease. _{O 2} max was greatly reduced in X-cell affected fish and substantially reduced their aerobic potential. This effect may impair the ability of diseased fish to catch prey and avoid predators.