Leafy Spurge Suppression by Flea Beetles in The Little Missouri Drainage Basin,USA

The Ecological Area-wide Management Leafy Spurge, or TEAM Leafy Spurge, began collecting and redistributing flea beetles (Aphthona spp.) to research/demonstration sites and landowners throughout the Little Missouri River drainage basin to control leafy spurge in 1998. A study to evaluate the change over time of leafy spurge (Euphorbia esula L.) phytosociological characteristics following release of flea beetles was initiated in 2002 on leafy spurge–infested pasture and rangeland in the Little Missouri River drainage of Montana, North Dakota, South Dakota, and Wyoming. A total of 292 flea beetle release sites were analyzed in June and July 2002 and 2003 for leafy spurge stem density, foliar cover, flea beetle density, and vegetation composition. Leafy spurge stem density suppression was evident at 91% of the study sites. On two-thirds of the study sites stem density was reduced from greater than 100 stems·m⁻¹ to less than 25 stems·m⁻¹. Leafy spurge foliar cover was less than 5% on approximately two-thirds of the flea beetle release sites and less than 25% on over 90% of the release sites. Area of observed leafy spurge suppression ranged from 0 m² to 30000 m². Approximately 40% of the release sites had leafy spurge suppression ranging from 1000 m² to 5000 m², and 14% of the release sites had greater than 10000 m² of leafy spurge control. Plant community composition following leafy spurge suppression was characteristic of native plant communities that had not been burned or grazed. Flea beetles effectively reduced leafy spurge stem density and cover in 4–5 yr across a variety of locations and corresponding environmental conditions, both within the Little Missouri River drainage and in selected nearby locations.     

Improving Potential Geographic Distribution Models for Invasive Plants by Remote Sensing

Remote sensing is used to map the actual distribution of some invasive plant species, such as leafy spurge (Euphorbia esula L.), whereas geospatial models are used to indicate the species’ potential distribution over a landscape. Geographic data layers were acquired for Crook County, Wyoming, and the potential distribution of leafy spurge presence or absence were predicted with the use of the Weed Invasion Susceptibility Prediction (WISP) model. Hyperspectral imagery and field data were acquired in 1999 over parts of the study area. Leafy spurge presence or absence was classified with the use of the Spectral Angle Mapper with a 74% overall accuracy. However, the user accuracy was 93%, showing that where leafy spurge was indicated in the image, leafy spurge was usually found at that location. With the use of Kappa analysis, there was no agreement between WISP model predictions and either the field data or the classified hyperspectral image. Kappa analysis was then used to compare predictions based on single geographic data layers, to increase the power to detect subtle relationships between independent variables and leafy spurge distribution. The WISP model was revised for leafy spurge based on the remote-sensing analyses, and only a few variables contributed to predictions of leafy spurge distribution. The revised model had significantly increased accuracy, from 52.8% to 61.3% for the field data and from 30.4% to 80.3% for the hyperspectral image classification, primarily by reducing the areas predicted to have potential for invasion. It is generally more cost effective to deal with the initial stages of invasion by only a few plants, compared to an invasion that is large enough to be detected by remote sensing. By reducing the potential area for monitoring, management of invasive plants could be performed more efficiently by field crews.     

Lack of Native Vegetation Recovery Following Biological Control of Leafy Spurge

Leafy spurge (Euphorbia esula L.) is an aggressive exotic species that has been successfully suppressed in a variety of situations using classical biological control (flea beetles; Aphthona spp.). This 9-yr study investigated patterns of vegetation responses following significant reductions in leafy spurge cover and density by flea beetles in southeastern Montana. We hypothesized that the vegetation following leafy spurge suppression would be dominated by species and plant functional groups able to persist through heavy infestations. Flea beetles were first released in 1998, and by 2006 leafy spurge foliar cover was reduced 80% to 90% compared to 1998 values on both release and nonrelease plots. Although total cover of the resident vegetation, excluding leafy spurge, increased 72% to 88%, relative cover of the functional groups (native forbs, native sedges, native grasses, and non-native species) was similar among years and between release and nonrelease plots. Mean diversity and mean species richness values did not differ among years or between release and nonrelease plots (P < 0.05), but mean diversity on both release and nonrelease plots was significantly less than noninfested plots, although richness was similar (P < 0.05). Indicator species analysis revealed that non-native Poa spp. replaced leafy spurge as the dominant species on release and nonrelease plots. Conversely, noninfested plots contained a variety of native species with high indicator values. Although total abundance of the resident vegetation in 2006 was significantly greater than 1998, plant species composition and relative cover showed little change for the duration of the study. Failure of the native vegetation to recover to a community that approached nearby noninfested conditions may be attributed to a variety of interacting scenarios, some of which may be ameliorated by treating infestations as soon as possible to avoid long-term residual effects.     

Behavioral, nutritional, and toxicological responses of cattle to ensiled leafy spurge

Yearling cattle (n = 25; 416.1 +/- 25.9 kg) were stratified by weight and gender across five groups. Group 1 (OAT) was offered oat/rape haylage (ORH) for ad libitum consumption during two daily feeding periods. Group 2 (SPURGE) was offered leafy spurge/grass haylage (LSGH) for ad libitum consumption during the same feeding periods. Group 3 was offered ORH in an amount equal to the average amount of LSGH consumed by SPURGE at the previous feeding. Group 4 (MIX) was offered LSGH mixed with ORH for ad libitum consumption during the two feeding periods. Group 5 (PAIR) received the equivalent amount of ORH consumed by MIX at the previous feeding. The DMI for OAT, SPURGE, and MIX were similar at the first feeding (P = .52). The SPURGE group consumed very little LSGH thereafter and was removed from the trial. The OAT and MIX groups consumed similar amounts of DM daily on d 1 to 4 when the ration offered to MIX was only 7% LSGH (P = .33). When LSGH made up > or = 21% of the mixture (d 7 to 32), the OAT group consumed more daily DM than did MIX (P < .05). The spurge/oatlage ration offered to MIX was less digestible than the oatlage-only ration offered to PAIR (P < or = .01). Even though blood chemistry did not indicate that LSGH consumption caused organ damage, its intake caused minor alterations (P < or = .05) in serum albumin, calcium, gamma glutamyltransferase, P, K, and urea nitrogen. No gross or microscopic lesions, infectious agents, or significant numbers of parasites were detected in any of the carcasses or tissues examined. The MIX group had diarrhea for much of the trial. In Trial 2, five yearling cattle were adapted to a mixture of 21% LSGH and 79% ORH. Then they were simultaneously offered three mixtures of spurge and oat haylages: 1) spurge ensiled with a microbial inoculant (LSGH); 2) spurge ensiled with the same inoculant and a cellulolytic/hemicellulolytic enzyme (ENZ); and 3) spurge ensiled with the same inoculant and molasses (MOL). The mixture with ENZ was preferred over those with MOL or LSGH (P < .001), but the amounts consumed were low and similar to those for LSGH-ORH in Trial 1 when amounts of ENZ and LSGH in the mixtures were similar. The ENZ mixture may have been more palatable than LSGH and MOL because it had less (P < .05) lactic acid, but intake of ENZ indicates that it had aversive characteristics, like LSGH. Ensiling leafy spurge did little, if anything, to improve its palatability to cattle.     

基于NDVI的植被覆盖度的变化分析——以甘肃省张掖市甘州区为例

为了分析张掖市甘州区自1987-2006年19年间的植被覆盖的变化,以归一化植被指数(NDVI)和植被覆盖度遥感定量模型为基础,以1987年、2006年2期的TM影像和张掖市1∶10万地形图为数据基础,提取两期的植被覆盖等级图,定量的分析该地区植被覆盖度的变化情况。结果表明：近19年来,该区的植被盖度总体略呈下降趋势,荒漠化草地等植被覆盖状况较差的地区植被退化较为严重,绿洲地区的植被覆盖较为稳定,部分地区植被盖度呈上升趋势。     

基于遥感分析13年来石羊河上游山区植被变化研究

NDVI是监测区域植被生长状况及植被覆盖度最常用的指标。基于2002和2015年9月上旬植被生长期内的Landsat TM遥感卫星影像,以ENVI 5.2软件为影像处理工具,分别获取两期影像的NDVI,研究内陆河石羊河流域上游祁连山山区植被覆盖度的变化;利用主成分分析法对两期影像进行了监督分类,获得各植被类型的面积以及变化情况。结果表明,2015与2002年相比,石羊河上游地区高覆盖度、中等覆盖度、低覆盖度植被面积均有所下降,分别下降了18.4%、13.4%、10.1%,而极高覆盖度和极低覆盖度面积均有所增加,分别增加了0.5%、26.6%。NDVI差值植被指数结果显示,上游地区植被发生退化的面积为6935.6154 km²,占总面积的51.26%,而发生改善的面积为6595.2834 km²,占总面积的48.74%。通过监督分类获得的各植被类型的面积显示,乔木林面积增长显著,13年间增长了108.75%,但是灌木林和草地的面积缩小严重,分别减少了49.87%、19.78%。祁连山石羊河流域上游森林植被在13年间呈现退化趋势。     

Mapping Total Vegetation Cover Across Western Rangelands With Moderate-Resolution Imaging Spectroradiometer Data

Remotely sensed observations of rangelands provide a synoptic view of vegetation condition unavailable from other means. Multiple satellite platforms in operation today (e.g. Landsat, moderate-resolution imaging spectroradiometer [MODIS]) offer opportunities for regional monitoring of rangelands. However, the spatial and temporal variability of rangelands pose challenges to consistent and accurate mapping of vegetation condition. For instance, soil properties can have a large impact on the reflectance registered at the satellite sensor. Additionally, senescent vegetation, which is often abundant on rangeland, is dynamic and its physical and photochemical properties can change rapidly along with moisture availability. Remote sensing has been successfully used to map local rangeland conditions. However, regional and frequently updated maps of vegetation cover in rangelands are not currently available. In this research, we compare ground measurements of total vegetation cover, including both green and senescent cover, to reflectance observed by the satellite and develop a robust method for estimating total vegetation canopy cover over diverse regions of the western United States. We test the effects of scaling from ground observations up to the Landsat 30-m scale, then to the MODIS 500-m scale, and quantify sources of noise. The soil-adjusted total vegetation index (SATVI) captures 55% of the variability in ground measured total vegetation cover from diverse sites in New Mexico, Arizona, Wyoming, and Nevada. Scaling from the Landsat to MODIS scale introduces noise and loss of spatial detail, but offers inexpensive and frequent observations and the ability to track trends in cover over large regions.     

遥感技术在高寒草甸及其退化草地上的应用研究

利用ＴＭ、ＳＰＯＴ卫片以及１９８５年、１９９７年２年地面观测资料．经遥感影像综合评判和ＱＩＳ表据处理．查明了达日县建设乡高寒草甸及其退化草地的面积。并得出以下结论：①卫片解译可以辩别退化草地和未退化草地；②沙丘和冲沟侵蚀一般无法与其它形式的退化草地相区别；③卫片可区分出草甸、灌丛和沼泽这３个草地类；④人沟管理的植被区只有在植被特征发生了显著的改观，才可以用遥感技术鉴别；⑤在草地规划和管理中，应用卫片具有很大的潜力。     

利用遥感技术对喜马拉雅山西北部高寒草地的研究

对大面积喜马拉雅山区高寒草地载牧量的动态监测是草地合理利用和自然资源保护的重要任务。该研究利用监督分类法绘制了1995年和1980年山格拉地区的植被图和土地利用图。在植被类型划分中成功地利用了数字三维模型作为辅助资料，提高了分类的准确性．通过卫星资料的分析表明，在森林线以上分布的主要植被有高寒草原、高寒草甸和山地草甸，弃荒地增加也表明“刀耕火种”是该区域重要的土地利用方式之一。通过对24个卫星光谱参数与不同草地类型上观测到的地面生物量进行了相关分析，建立了正规化植被指数与草地生物量之间的相关模型。利用陆地卫星TM和陆地卫星MSS资料，分别对1980和1995年的草地载畜能力进行估测。在1980年，山格拉地区堪达草地约有4l％饲草剩余，在1995年的理论草地载畜量为12035个羊单位。即在传统的放牧制度下，暖季游牧家畜数量还可以增加1倍。这种当地游牧制度是印度高寒草地一直保持良好草地基况的关键所在。本研究就提高高寒草地家畜生产力提出了一些合理化建议。     

天山北坡草地遥感分类及其精度分析

基于遥感资料的植被类型划分能快速获得大尺度的植被覆盖变化数据。采用遥感和GIS技术,利用天山北坡典型草地2008年Landsat 5 TM遥感影像和1999年Landsat 7 ETM+全色波段数据,在对遥感影像预处理的基础上,进行了数据融合处理。根据融合影像的纹理特征进行监督分类,将研究区域的植被初步分为8种主要覆盖类型,在监督分类的基础上借助专家知识系统构建决策树,进一步将草地分为5类,包括平原荒漠、平原沙漠、低山荒漠、温性草甸和高寒草甸,最后对分类结果进行精度评价,总精度在95%以上,总Kappa系数为0.939 6,间隔9年的影像融合和决策树分类方法在研究区植被分类中具有较高的可行性。     

基于马尔柯夫模型的草原退化动态时空特征研究

草原植被覆盖动态时空特征是理解人类活动和自然因素影响下草原退化的关键。本研究利用2000和2010年TM影像,利用监督分类方法,对内蒙古草原退化、沙化和盐渍化时空分布特征探测和制图,同时对分类结果进行验证。检验结果表明,采用监督分类结合地面训练样本进行草原退化动态特征检测能提高分类精度,草原沙化和盐渍化分类精度分别都达到90%以上,退化草原分类精度为75%。在草原退化程度分类检测基础上,计算2000-2010年草原退化、沙化、盐渍化面积概率转移矩阵,并基于马尔柯夫模型,对未来20年间草原动态特征进行预测。研究结果表明,十年间,内蒙古草原的退化、沙化程度均呈减弱趋势。预测结果显示,在草原与生态保护建设工程持续稳定有效建设前提下,内蒙古草原呈现良性发展趋势,退化及沙化状况将持续得到改善。研究也指出,基于遥感技术与马尔柯夫模型有机结合分析草原退化动态特征是一种快速有效的途径。     

新疆福海县草地资源变化研究

采用1999年TM和2008年ETM+遥感影像,结合野外调查,利用GIS软件人机交互式解译提取福海县草地资源信息,以此进行其在时空上的变化.研究结果表明:福海县草地退化严重,低、中、高覆盖度草地均有不同程度的退化,退化面积分别占其总面积的22.06%,45.01%和62.25%,高覆盖度草地退化最严重;分析了导致研究区...     

吉林省大安市草地资源动态变化研究--基于RS和GIS的遥感调查

采用时间尺度为15年的1987年TM和2002年ETM 美国LANDSAT卫星遥感影像,结合野外调查、各种图件和文字资料,利用GIS软件人机交互式解译提取大安市草地信息,以此进行了时间和空间序列动态变化分析。结果表明,大安市草地退化严重,低、中、高覆盖度草地均有不同程度的退化,退化面积分别为22.06%、45.01%、62.25%,高覆盖度草地退化最严重;并分析了导致研究区草原退化的自然因素和人为因素,提出了恢复该区草原生态环境的治理措施。     

基于野外观测和TM数据的锡林浩特典型草原MODIS/LAI产品验证

通过2008年夏季生长季的3期LAI野外观测和TM图像的处理分析,对锡林浩特国家观象台附近24 km²典型草原区的MODIS/LAI产品精度从时空2种维度进行了评估。结果显示,在时间维度上,MODIS/LAI产品可以较为准确的体现草地植被生长轨迹;在空间维度上,MODIS/LAI产品与TM/LAI反演结果有相似的变化趋势。以TM/LAI结果为参考真值,MODIS/LAI产品的相对均方根误差约为24%,并存在10.8%的正偏差,表明有一定程度的高估。误差分析结果显示,MODIS/LAI产品精度主要受到土壤背景光谱以及地表均匀程度的影响,在LAI较小的区域,以及在草地空间异质性因受人类活动而增强的7月初和8月末,MODIS/LAI产品误差更大。     

基于3S技术的西藏岗巴草原资源空间格局分布现状

基于遥感（Remote Sensing,RS）、地理信息系统（Geographic Information System,GIS）和全球定位系统（Global Position System,GPS）,即3S技术,应用面向对象的自动分类与人机交互分类结合判读方式,以SPOT、TM影像为背景,结合地面调查样地及历史资料,准确获得岗巴县草原类型空间分布现状图件及统计数据。根据本次调查结果表明：岗巴县草原总面积为365222.89hm2,占岗巴县国土面积86.94%。该县草原类型共划分4个草原大类、6个草原亚类、21个草原型。各类草原类型面积最大为高寒草原类,占总草原面积58.66%;其次是高寒草甸类,占38.61%;第三位是高寒草甸草原类占2.56%;低地草甸类面积最少,占0.18%。该县草原退化、沙化、盐渍化面积为3809.91hm2,占该县草原面积的46.36%,其中草原退化面积31.44%;草原沙化占12.96%;草原盐渍化占1.96%。草原畜牧业是该县农牧民收入的重要来源,科技与政策支持是恢复草原资源,改善生态环境及可持续发展畜牧业的重要对策。     

草地资源遥感调查方法的研究

七十年代以来,遥感技术发展十分迅速,它广泛地应用于地质、地理、土壤、森林、草地等多种学科。草地资源遥感调查就是利用遥感技术调查草地的数量、质量和分布,它更新了常规调查的方法和手段,缩短了调查周期,改变了草地资源图件的制图工艺和流程,提高了总体调查的准确性。新一代陆地资源卫星遥感影像的应用,明显提高了地类的可判性和判读精度,增加了各类草地面积数据的可靠性,特别是经过 TM 波段比较值处理和 TM 缨帽变换等处理后的影像,质量较高,其解译精度完全符合大面积草地资源调查的精度要求。     

猪肝星状细胞内质网应激模型的建立及对泛素化的影响

试验对衣霉素（tunicamycin,TM）处理猪肝星状细胞的浓度和培养时间进行筛选,以期成功构建内质网应激（endoplasmic reticulum stress,ERS）模型,并在此基础上探究ERS下猪肝星状细胞泛素化的变化。试验采用浓度为0、1、2、5、10和15 μg/mL的TM处理猪肝星状细胞,培养2、4、8、16、24和36 h。通过检测细胞抑制率对TM浓度和培养时间进行初筛;通过检测细胞周期及ERS标志基因和蛋白表达对TM浓度和培养时间进行终选,以确定是否成功构建ERS模型,同时,在ERS下检测猪肝星状细胞泛素化相关基因的表达变化。结果表明：由细胞抑制率检测结果初步确定TM浓度5 μg/mL、培养8或24 h后有可能出现ERS。5 μg/mL TM在培养8或24 h时,ERS标志基因表达均极显著上调（P < 0.01）。在培养8 h时,ERS标志蛋白中仅ATF4显著上调（P < 0.05）,细胞周期中仅G2/M期细胞比例显著下降（P < 0.05）;在培养24 h时,ERS标志蛋白均显著上调（P < 0.05）,细胞周期在G1期出现阻滞,并导致S期和G2/M期细胞比例极显著下降（P < 0.01）。以上结果说明,5 μg/mL TM培养24 h可成功构建细胞ERS模型。在ERS下,细胞泛素化相关基因UBA2和UBE2E的表达均极显著升高（P < 0.01）。综上,猪肝星状细胞经5 μg/mL TM处理24 h,可成功建立ERS模型,并启动泛素化机制。     

Can Sheep Control Invasive Forbs Without Compromising Efforts to Restore Native Plants?

Domestic sheep (Ovis aries) are increasingly being used to control non-native invasive plants in areas where restoration is a management goal. However, the efficacy of sheep grazing depends on both its potential for controlling undesirable plants and its ability to promote natives. To date, few studies have investigated impacts of sheep grazing on native forb recovery in North American grasslands. We assessed the impact of sheep on forbs by measuring the number of stems grazed before and after sheep foraged in western Montana, United States. Sheep grazed a higher percentage of non-native than native forbs (70% vs. 23%, respectively), and number of stems grazed was six times higher for non-natives than natives (48 vs. 5, respectively). Sheep preferentially selected the non-native forbs sulphur cinquefoil and yellow salsify over leafy spurge (fi = 2.075; fi = 0.969; fi = 0.969, respectively), as well as the native forbs white prairie aster (fi = 1.090) and blanketflower (fi = 1.000). Selection of native forbs was positively correlated with their pregrazing abundance and increased over the grazing period. Our findings indicate that when using sheep to control invasive forbs, appropriate timing and monitoring of grazing are critical for reducing nontarget impacts to native vegetation.     

近30年北京市高尔夫球场时空变化特征

以北京市1986-2010年Landsat TM/ETM+遥感影像为基础,通过数字化和影像解译获取北京市75个面积大于6 hm²的高尔夫球场数据,并利用土地利用/土地覆盖数据和地理要素数据(道路、行政区划、水域等),从时空角度研究近30年北京市高尔夫球场的时空变化特征。结果表明,1)1986年至2010年,北京市高尔夫球场经历了“初步建立、停滞发展、缓慢发展和迅速发展”的变化过程,其中1990-1999年期间高尔夫球场处于停滞发展期,2000-2005年出现缓慢发展,2005年之后迅速增长。2)并非所有高尔夫球场均呈面积增加趋势,而是具有空间差异性。3) 高尔夫球场面积变化与土地利用/土地覆盖类型变化高度相关,高尔夫球场变化趋势和土地利用动态度的变化趋势保持着一致性。4)北京市高尔夫球场主要沿着具有紧邻中心城区、滨临河湖、临近快速交通线的优势空间区位分布,特别是“一环两带”地区。     

INTRAARTERIAL CONTRAST-ENHANCED COMPUTED TOMOGRAPHY OF THE EQUINE DISTAL EXTREMITY

A technique for regional delivery of contrast medium to the foot of the horse to increase the diagnostic utility of computed tomography (CT) for the characterization of soft tissue structures within the hoof capsule was developed. An intraarterial catheter was placed under ultrasound guidance into the medial palmar artery at the level of the carpus to facilitate a steady-state infusion of iodinated contrast medium. Two 5 mm collimated contiguous acquisition CT scans were performed in 10 horses without lameness or radiographic evidence of distal sesamoid bone degeneration. CT examination was performed before and during regional arterial infusion of iodinated contrast medium administered at a rate of 2 ml/s. Cross-sectional area and mean pre- and post-contrast attenuation of the deep digital flexor tendon and the collateral ligaments of the distal interphalangeal joint were quantified from CT images. Soft tissue anatomy of the foot was also qualitatively characterized from pre- and postcontrast images. Catheterization was successful and without complication in all horses. The evaluated tendons and ligaments were clearly visible and had a small (8-20 Hounsfield Unit) but significant (P < 0.05, paired t-test) increase in attenuation during the steady-state infusion of contrast medium. This study should enhance the diagnostic potential of CT by providing baseline quantitative data for comparison with horses affected with soft tissue injuries in the distal extremity causing lameness that is alleviated with a palmar digital nerve block.