Applying broadband spectra to assess biological control of saltcedar in west Texas     

Reginald S. Fletcher 《国际地球制图》2013,28(4):383-399

Broadband field spectra were assessed to discriminate invasive saltcedar (Tamarix spp.) trees exhibiting feeding damage caused by the saltcedar leaf beetle (Diorhadba spp.) from other land cover types. Data were collected at two study sites near Presidio, Texas in 2010 and 2011. Spectral bands evaluated were coastal blue (400–450?nm), blue (450–510?nm), green (510–580?nm), yellow (585–625?nm), red (630–690?nm), red-edge (705–745?nm), and near-infrared (770–895, 860–1040?nm). Data were evaluated with analysis of variance and Scheffe’s multiple comparison test (α?=?0.05). The red band generally separated severely damaged saltcedar trees from other land cover features. Near-infrared bands separated defoliated saltcedar trees. Broadband spectra has potential for distinguishing saltcedar trees exhibiting feeding damage caused by the saltcedar leaf beetle from other associated features, thus supporting future explorations of airborne and satellite-borne multispectral systems to monitor biological control of saltcedar within complex landscapes.  相似文献   

Genetic connectivity among populations of two congeneric direct-developing whelks varies across spatial scales     

Angela M. Fleming  Melanie M. Dohner  Peter A. Ritchie 《新西兰海洋与淡水研究杂志》2018,52(1):100-117

We examined the phylogeographic structure of two congeneric, direct-developing, intertidal whelks endemic to New Zealand, Cominella virgata and C. maculosa. A total of 855 specimens were collected from 23 rocky shore locations and we used them to determine the level of DNA sequence variation at the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I gene. Cominella virgata and C. maculosa have relatively high levels of haplotype diversity but low levels of nucleotide diversity. Sample sites formed regional groups that were composed of genetically differentiated populations, a finding consistent with their limited dispersal abilities. Cominella virgata showed higher levels of regional differentiation than C. maculosa, and there were also species-specific differences in genetic patterns within some regions. Both species exhibited genetic homogenisation among proximate sites within groups, suggesting some dispersal does occur between areas that are not connected by contiguous rocky shore habitat.  相似文献   

干旱对大豆叶片葫芦巴碱含量和渗透调节的影响   总被引：7，自引：5，他引：2  

王蕊  孙广玉 《中国沙漠》2010,30(3):552-555

以两个抗旱性不同的大豆品种绥农14号和黑农38号为研究材料,研究了土壤干旱胁迫下大豆叶片葫芦巴碱含量的变化和渗透调节能力。结果表明,土壤干旱下两个大豆品种叶片水势、渗透势和压力势降低,且绥农14号叶片的压力势在干旱胁迫下明显高于黑农38号。干旱胁迫下两个大豆品种的渗透调节能力提高。在0~8 d 干旱期间,叶片的葫芦巴碱含量增加较快,脯氨酸含量增加较慢;在8~12 d干旱期间,叶片中葫芦巴碱含量下降,而脯氨酸含量迅速增加。因此,葫芦巴碱在轻度干旱下可能起到渗透调节物质的作用,在严重干旱下该作用减弱。  相似文献   

新疆沙冬青叶片蛋白质的双向电泳技术研究   总被引：1，自引：1，他引：0  

鲁春芳  尹林克 《中国沙漠》2011,31(1):96-100

提取新疆沙冬青叶片中蛋白质受到脂类、酚类等次生代谢产物的干扰,针对这种现象,进行了组分提取优化方法和双向电泳技术的改进。实验分析表明,用乙醚淋洗完整叶片,50 mmol·L-1 Tris-HCl缓冲液,上样量240 μg（7 cm胶条）,考马斯亮蓝染色等方法可很大程度增加提取可溶性蛋白含量,结合丙酮-三氯乙酸的沉降,可较完整地提取蛋白质组。  相似文献   

日本岩垂草在岩溶山地的生态效益研究   总被引：1，自引：0，他引：1  

刘小瑜  谢世友  李勇  张远瞩 《中国岩溶》2012,31(1):12-15

本文首次在岩溶山地生态重建中引进优质草种——日本岩垂草(Lippianodiflora (L.) Greene),通过对其盖度、根系特征、径流量和抗侵蚀能力的研究,探讨其在岩溶山地的生态效益,寻求修复岩溶地区脆弱生态系统的途径,并为日本岩垂草在岩溶山地种植推广提供依据。试验表明,日本岩垂草对降低地表径流量收效明显,在种植了3个月后,地表径流量已经由110mm下降到42mm,下降了62%;抗侵蚀能力强,在同样的雨强和降雨量情况下,其侵蚀量只是传统耕地的5.60%~5.83%;根系生长速度快,密度大,数量多,种植90d时盖度已达100%。实验证明,日本岩垂草具有优秀的生态修复和生态美化能力,能够有效地改善岩溶地区脆弱的生态状况。   相似文献   

大亚湾海域石斑鱼(Epinephelus spp.)寄生单殖吸虫群落结构研究   总被引：1，自引：0，他引：1  

曾碧健  黄建荣  杨廷宝 《海洋与湖沼》2017,48(2):406-414

调查了大亚湾海域13种石斑鱼(Epinephelus spp.)寄生单殖吸虫群落,结果发现有10种鱼感染单殖吸虫,占调查鱼种类的四分之三,检获单殖吸虫16种,隶属于3科5属,其中拟合片虫属(Pseudorhabdosynochus spp.)10种;除鞍带石斑(E.lanceolatus)和拟青石斑(E.fasciatomaculosus)外,8种鱼可分别感染3—7种单殖吸虫;感染单殖吸虫种类最多的是玳瑁石斑(E.quoyanus)达7种,次之是青石斑(E.awoara)和养殖的橙点石斑(E.bleekeri)均感染6种;各单殖吸虫种类中,感染强度最大的是拟合片虫(P.serrani))(棕点石斑,E.fuscoguttatus)128只/尾,次之是石斑拟合片虫(P.grouperi)(青石斑)62只/尾,接下来是斜带拟合片虫(P.coioidesis)(大斑石斑,E.macrospilos)59只/尾和杯阴拟合片虫(P.cupatus)(玳瑁石斑)49只/尾;平均密度最高的是棕点石斑上检获的拟合片虫128只/尾;在检获的16种单殖吸虫中,8种可分别寄生于2种或2种以上石斑鱼,石斑鳞盘虫(Diplectanum grouperi)和拟合片虫在6种石斑鱼上都能检获,符合广寄生单殖吸虫种特征。有5种鱼检查尾数5尾以上的,其中玳瑁石斑单殖吸虫感染率最高62.07%,其内群落的物种丰富度与宿主体长呈显著正相关。  相似文献   

富集培养条件下湖泊和沿海海域水体硫酸盐还原菌的耐氧性特征     

陈亚文  张朝晖 《高校地质学报》2019,25(5):705

硫酸盐还原菌（sulfate-reducing bacteria,SRB） 是一类兼性厌氧菌,在湖泊和海洋有机物矿化过程和生物源性黄铁矿 的生成过程中都扮演着重要角色。环境溶解氧浓度对硫酸盐还原过程影响较大,硫酸盐还原菌在水体中的耐氧性是目前的研 究热点。文章采集了象山港和水口水库不同溶解氧水平下的水样,并在相应的溶解氧梯度下进行富集培养,以探讨不同溶解 氧浓度下硫酸盐还原菌的耐氧性特征及硫代谢相关菌的组成。结果显示,在富集培养条件下湖泊和沿海海域中Desulfovibrio （脱硫弧菌属） 和Desulfomicrobium （脱硫微菌属） 为主要硫酸盐还原细菌,而Shewanella （希瓦氏菌属） 和Sulfurospirillum （硫小螺体属） 为其硫代谢相关菌。Desulfovibrio的相对丰度与溶解氧水平密切相关,随溶解氧浓度的减少,其相对丰度增加。 SRB 的耐氧上限为6.68 mg/L,明显高于以往纯培养或共培养的耐氧上限值。作者推测这不仅与其高氧环境的适应策略有关, 还可能得益于共存菌的贡献,后者可能通过消耗环境中的氧为Desulfovibrio提供生态位,提高其耐氧水平。  相似文献   

Simultaneous estimates ofsynechococcus spp. Growth and grazing mortality rates in the English Channel     

Ning Xiu-ren  Daniel Vaulot 《中国海洋湖沼学报》1996,14(1):8-16

The marine chroococooid phycoerythrin-containingSynechococcus spp. cyanobacterium has been implicated as a substantial component of the photosynthetic picoplankton in the ocean. Although its importance as food source for heterotrophic nanoplankton is now recognized, information about the cycling ofSynechococcus biomass and its diel pattern is limited and study methodology varies among authors. The selective metabolic inhibitor method was used to simultaneously estimate growth and grazing disappearance rates ofSynechococcus in the English Channel where growth rates ranged from 0.25 to 0.72/d (mean ±SD=0.51±0.17/d) and grazing mortality rates ranged from 0.19 to 0.64/d (mean ±SD=0.48±0.17/d). Size-fractionated experiments demonstrated that up to 70% ofSynechococcus disappearance could be attributed to grazers going through a 2 μm Nuclepore filter.Synechococcus grazing mortality rates (mean=0.74 ±0.25/d) during the day were always higher than that (mean=0.2±0.20/d) during the night, while growth rates showed no clear diel pattern. A positive correlation was observed between growth rates andin situ temperature ranging from 9 to 17°C, while in contrast grazing was independent of temperature. The close similatiry between average growth and grazing rates suggests a rapid recycling ofSynechococcus biomass in English Channel coastal waters.  相似文献   

A survey of imposex in muricids from 1996 to 2000 and identification of optimal indicators of tributyltin contamination along the east coast of Phuket Island,Thailand     

Bech M 《Marine pollution bulletin》2002,44(9):887-896

The present investigation is the most extensive survey of imposex in gastropods from the west coast of Thailand. Imposex in Thais distinguenda increased significantly (p < 0.001; Chi Square test for trend) from 1996 to 2000 at 21 stations in Phangna Bay, Thailand. Females with imposex increased, extending from 3.5 km in 1996 to 10 km from the harbour areas in 1999 and 2000. Increasing intensity of imposex was also observed for Thais bitubercularis from 1996 to 2000. The less sensitive species: Morula musiva, Morula granulata, Morula margariticola and Thais rufotincta only developed imposex at the three main areas of intense shipping activities. T. bitubercularis and T. distinguenda are recommended as indicators of tributyltin (TBT) in Southeast Asia because of their sensitivity and wide distribution in the region. The results suggest that TBT contamination is worsening, against global trends, because regulations prohibiting the use of TBT-based paints, do not exist in Thailand.  相似文献   

丘陵红壤区决明属牧草品系的适应性筛选   总被引：12，自引：0，他引：12  

黄毅斌  应朝阳  黄金煌  庄绍东  翁伯奇 《山地学报》2004,22(6):742-749

针对占全国总面积22％的南方红壤区有机质含量低、酸性强、水土流失严重等生态问题，及福建省当家豆科草种少等问题。引进40个豆科决明属(Chamaecrista spp．)牧草，在福建省不同气候带的红壤山地进行多年适应性筛选和验证试验。通过聚类分析和建立综合指标评价体系，筛选出适宜荒山荒坡地种植的直立型品种C．nictitans ATF2217、ATF2219，适宜于果园套种的匍匐型品种C．rotundifolia CPI34721、CPI92985和适宜保持水土改良土壤的C．rotundifolia CPI86134、CPI86178等6个品系进行推广利用。其中Chamaecrista nictitans cv．ATF2217已通过全国牧草品种审定，定名为“闽引羽叶决明”。  相似文献