肃北县草原资源调查

通过应用3S技术一体化与固定样地、路线调查相结合,对肃北县天然草原资源进行调查,确定了肃北县草地类型、面积、分布及物种组成,并对草地盖度、高度和产草量进行了监测研究。结果表明,1)肃北县有天然草原5 181 889 hm2,划分为9个类,17个亚类,19个组,29个型;2)肃北县各类草原鲜草产量从高到低依次为:低平地草甸5 093 kg/hm2,温性草原化荒漠3 094 kg/hm2,高寒草甸2 561 kg/hm2,高寒灌丛草甸1 933 kg/hm2,高寒荒漠1 822 kg/hm2,温性荒漠化草原1 665 kg/hm2,温性荒漠1 183 kg/hm2,高寒草原1 143 kg/hm2,温性草原760 kg/hm2;3)肃北县天然草原年总产鲜草886 091.71万kg,折合干草(风干)304 763.85万kg;肃北天然草原理论载畜量为135.42万羊单位,目前全县各类牲畜折40.75万羊单位;4)肃北县具有丰富而珍贵的植物资源,南部祁连山区分布的植物有210种,分属42科129属,其中中低等以下的牧草有185种,占植物群落的88%;中等以上的有25种,占12%;马鬃山区分布的植物种有86种,分属23科54属,其中优良牧草有70种,占植物群落的81%。     

Canine Dirofilaria immitis infection in a hyperenzootic area: examination by parasitologic findings at necropsy and by two serodiagnostic methods

A total of 174 dogs from an area hyperenzootic for Dirofilaria immitis were grouped into 4 age categories and necropsied; information was obtained on adult D immitis infections and on the presence of microfilariae. Serum samples from these dogs were examined by an enzyme-linked immunosorbent assay (ELISA) for antibody to adult D immitis and by an indirect fluorescent antibody test (IFAT) for antibody to microfilarial surface antigens. In dogs less than or equal to 5 months of age, necropsy demonstrated no evidence of infection; however, positive serologic results indicated that some of these dogs had prepatent infections. The percentage of dogs with ELISA titers (positive) increased with age, as did the percentage of dogs with adult D immitis infections. The IFAT results were positive in some dogs in each age category. Sera from all 29 dogs with occult infections were positive by ELISA. Sera from 6 of 20 dogs with occult dual-sex heartworm infections and 1 of 9 dogs with occult single-sex heartworm infections were positive by IFAT. For diagnosing occult dirofilariasis, the ELISA had a positive predictive value which increased with age of the dog to a maximum of 65.0% in dogs greater than or equal to 12 months of age; ELISA had a negative predictive value of 100% in all age groups. In contrast, positive and negative predictive values for the IFAT decreased with age of the dog to 60% and 37.5%, respectively, in dogs greater than or equal to 12 months of age.     

燕麦根系对缺磷胁迫的适应性反应

采用溶液培养的方法,在燕麦苗期,研究了磷素充足供应和缺磷胁迫两种条件下根系形态指标的变化。结果表明,经过30d的缺磷胁迫,燕麦根系生物量显著低于充足供磷处理,但根系总长并未表现为缺磷处理显著低于充足供磷处理,而且根冠比、比根长却表现为缺磷处理显著高于磷素充足供应处理。缺磷条件下比根长的增加与根轴直径的减小是一致的,因此根轴横向生长减弱可能是导致缺磷燕麦根系比根长增加的原因。由于比根长的增加意味着消耗同样的同化产物,却可以形成具有较大吸收范围的根系,因此燕麦根轴直径减小、比根长的增加是燕麦对缺磷胁迫的适应。     

Integrating airborne lidar and satellite imagery to model habitat connectivity dynamics for spatial conservation prioritization

Context

The application of regional-level airborne lidar (light detection and ranging) data to characterize habitat patches and model habitat connectivity over large landscapes has not been well explored. Maintaining a connected network of habitat in the presence of anthropogenic disturbances is essential for regional-level conservation planning and the maintenance of biodiversity values.

Objectives

We quantified variation in connectivity following simulated changes in land cover and contrasted outcomes when different conservation priorities were emphasized.

Methods

First, we defined habitat patches using vegetation structural attributes identified via lidar. Second, habitat networks were constructed for different forest types and assessed using network connectivity metrics. And finally, land cover change scenarios were simulated using a series of habitat patch removals, representing the impact of implementing different spatial prioritization schemes.

Results

Networks for different forest structure types produced very different patch distributions. Conservation scenarios based on different schemes led to contrasting changes during land cover change simulations: the scheme prioritizing only habitat area resulted in immediate near-term losses in connectivity, whereas the scheme considering both habitat area and their spatial configurations maintained the overall connectivity most effectively. Adding climate constraints did not diminish or improve overall connectivity.

Conclusions

Both habitat area and habitat configuration should be considered in dynamic modeling of habitat connectivity under changing landscapes. This research provides a framework for integrating forest structure and cover attributes obtained from remote sensing data into network connectivity modeling, and may serve as a prototype for multi-criteria forest management and conservation planning.

     

50 a来内蒙古荒漠草原气候干燥度的空间分布及其演变特征

根据内蒙古荒漠草原11个气象观测站1961-2010年的日平均气温、降水量资料,采用改进的谢氏干燥度计算公式,并利用ArcGIS软件分析内蒙古荒漠草原50 a来气候干燥度的时空变化规律。结果表明：① 平均干燥度呈条带状自东南向西北逐渐递增,表明干燥程度由东南向西北逐渐加强;② 除中部偏西（海流图地区）干燥度减少、气候趋于湿润化外,其他地区干燥度指数呈增加趋势,说明内蒙古荒漠草原地区气候干旱化趋势明显;③ 20世纪70年代属于相对湿润期,21世纪初干旱程度明显加大。其结果导致干旱区面积随年代增加,至21世纪初干旱区面积增加了近3倍,从另一个侧面说明研究区域气候干旱化趋势显著;④ 干燥度4.0等值线向东南方向移动,逐渐侵入典型草原。以20世纪60年代为基点, 90年代前变幅相对较小,21世纪初的偏移范围最大。此外,该线在研究区域东部变化强烈,空间位移幅度大,西部相对变化较弱,空间位移相对较小。     

亚洲小车蝗痘病毒田间杀虫效果

１９９４～１９９６年间在内蒙古利用亚洲小车蝗痘病毒防治草原蝗虫的初步试验结果：田间罩笼试验用５×１０７ＯＢＳ／ｍｌ的病毒包涵体悬浮液喷雾，２４～２６天校正虫口减退率为７２．９％～７３．３％；虫口减退进程曲线呈Ｓ型；处理１０天后虫口减退率即呈明显的上升趋势，处理后２０天虫口减退趋势逐步减缓，田间小面积试验用７．５×１０９、７．５×１０８和７．５×１０７ＯＢＳ／ｈｍ２分别与麦麸ｌ．５ｋｇ配成饵剂撒施，处理后３８天校正虫口减退率达５８．０％、４２．０％和３２．７％。     

地籍数据库在杭锦旗锡尼镇建筑密度与容积率分析中的应用

本文以干旱区小城镇——锡尼镇为研究对象,从地籍调查建立的地籍数据库中提取信息,快速、准确地对锡尼镇的建筑密度和容积率进行了分析,对提高该镇的土地利用率、合理配置和最佳使用各类土地提供了指导意见     

锡林河流域紫花苜蓿需水规律与灌溉定额优化研究

为了确定锡林河流域紫花苜蓿生育期内不同阶段的需水量、需水规律和合理的灌溉定额。采用非充分灌溉试验,研究了紫花苜蓿的需水规律、产量与灌溉定额间的关系以及合理灌溉定额。结果表明：第1 茬紫花苜蓿需水高峰值出现在6 月下旬—7 月初,其需水强度最大可达5.09 mm/d;第2 茬紫花苜蓿需水高峰值出现在8 月上旬—8 月中旬,其需水强度最大可达5.23 mm/d。根据紫花苜蓿产量与灌溉定额间表现为二次抛物线型关系,以追求单位面积产量、灌溉水生产效率和生产弹性系数最大为目标,确定紫花苜蓿的合理灌溉定额,该成果为节水灌溉制度的制定和灌溉预报等提供了科学依据。     

肃南肃北草原野生动物资源调查研究

通过对肃南、肃北草原野生动物资源3年的调查研究分析,结果表明,祁连山地及马鬃山区草原地带活动的主要陆生脊椎野生动物种群可划分为5个类群,高山寒漠动物群、高山草甸动物群、荒漠动物群、沼泽动物群和村庄农田动物群,有蹄类、食肉类、爬行类、两栖类、鱼类、啮齿类、鸟类及昆虫类约有800多种;国家级保护动物共有34种,占肃南、肃北鸟兽种数的26%。其中国家一级保护动物有10种;国家二级保护动物有24种。     

肃南、肃北草地类型及草地植物物种多样性现状

“草场类型和草地植物资源调查”于2007-2008年在甘肃省肃南裕固族自治县和肃北蒙古族自治县实施。调查共测定草本植被样方226个,灌丛植被样方125个,草灌乔植被样方32个;现场标图约22500km²,调查路线长18500km。按照《中国草地类型的划分标准和中国草地类型分类系统》确定肃南县草地类型有9类、18个亚类、24组、29型;肃北县草地类型有9类、17个亚类、19组、29型;采集植物标本986份381种,分属53科,176属;其中牧草类植物300种。肃北、肃南草场的总体状况在退化,局部地方保护较好;除气候因素外,超载过牧是加速草场退化的主要原因,其次为鼠害;蝗虫不是造成草场植被退化的原因。调查区草地植物的物种多样性没有遭到大的破坏,但各种群的优势度变化较大,表明群落中种群关系已经发生了变化,生物多样性受到威胁。