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991.
South Africa experienced a severe multiyear drought from 2014 to 2016. Here, we explore the response of a South African savannah ecosystem to this drought focusing on tree and grass dynamics. We used open long‐term monitoring plots established in 2000 and distributed across broad rainfall gradients in the Hluhluwe‐iMfolozi Park in KwaZulu‐Natal. Analysis showed negligible tree mortality due to drought in 2016 (0.03%) and 2017 (0.49%). However, there was an apparent increase in the tree population especially among the small size classes (0.1–0.3 m) in 2016 and 2017 relative to the predrought 2012 census. Drought effects may be confounded with changes in browser populations. The impala population declined in a mesic savannah (Hluhluwe), as measured with dung counts; however, this decline started before the drought. Impala decline in a semi‐arid savannah (iMfolozi) was more coincident with drought. Grass biomass and cover decreased in 2016 compared to predrought 2012 but showed rapid recovery once rains began. In iMfolozi grass species, composition improved from a grazing perspective as a result of the recovery of the decreaser species, an increase in palatable species and a marked decline of unpalatable species. The minor changes in woody plants and grasses from before the drought until rain resumed and the rapid recovery of grasses suggest that this South African savannah ecosystem was resilient to severe drought. 相似文献
992.
Siripar Korinsak Sithichoke Tangphatsornruang Wirulda Pootakham Samart Wanchana Anucha Plabpla Chatchawan Jantasuriyarat Sujin Patarapuwadol Apichart Vanavichit Theerayut Toojinda 《Genomics》2019,111(4):661-668
Magnaporthe oryzae is a fungal pathogen causing blast disease in many plant species. In this study, seventy three isolates of M. oryzae collected from rice (Oryza sativa) in 1996–2014 were genotyped using a genotyping-by-sequencing approach to detect genetic variation. An association study was performed to identify single nucleotide polymorphisms (SNPs) associated with virulence genes using 831 selected SNP and infection phenotypes on local and improved rice varieties. Population structure analysis revealed eight subpopulations. The division into eight groups was not related to the degree of virulence. Association mapping showed five SNPs associated with fungal virulence on chromosome 1, 2, 3, 4 and 7. The SNP on chromosome 1 was associated with virulence against RD6-Pi7 and IRBL7-M which might be linked to the previously reported AvrPi7. 相似文献
993.
The Neotropical genus Cephaloleia Chevrolat (Coleoptera: Chrysomelidae: Cassidinae) includes 214 species distributed from the south of Mexico to Argentina. Cephaloleia beetles feed mostly on plants from the order Zingiberales. The interactions between Cephaloleia beetles and their Zingiberales host plants is proposed as one of the oldest and most conservative associations. Here we describe a new species of Cephaloleia (Cephaloleia
kuprewiczae
sp. n.) that feeds on two species of bromeliads (Pitcairnia
arcuata and Pitcairnia
brittoniana, Bromeliaceae: Pitcairnioideae). Cephaloleia
kuprewiczae was previously described as Cephaloleia
histrionica. This study includes evidence from DNA barcodes (COI), larval and adult morphology and insect diets that separates Cephaloleia
kuprewiczae from Cephaloleia
histrionica as a new species. 相似文献
994.
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996.
近年来,由于野猪(Sus scrofa)数量增长和土地利用方式的变化,导致人与野猪之间的冲突不断增加。2018年8-10月在吉林省珲春地区利用东北虎声音、野猪惨叫声、狼叫声,太阳能警示灯、防兽彩带等视觉设施,东北虎粪便,综合使用东北虎声音和东北虎粪便以及电子围栏等防控措施在已使用过和未使用过防控措施的样地开展了野猪危害防控效果及空间特征研究。我们以2018年野猪危害防控研究的数据,结合2011-2017年已发表数据进一步研究了野猪危害防控措施的时空特征。防控有效期为实验开始到野猪首次进入样地发生危害的时间间隔。研究结果表明:(1)2018年实验组与对照组相比,防控有效期均存在显著差异(P< 0.001),对照组防控有效期为(1.33±0.58)d,实验组中已使用过和未使用过防控措施样地的防控有效期分别为(16.25±9.00)d和(20.58±9.61)d,防控有效期差异不显著(P=0.127);(2)2018年与2011年、2013年、2016年、2017年相比同一种防控措施的防控效果随着使用年份的增加,播放东北虎声音1min加空白5min、放置避雨装置的粪便、综合使用东北虎声音加粪便、放置红黄绿色太阳能警示灯等防控措施的防控有效期没有显著变化(P=0.200;P=0.295;P= 0.221;P=0.080;P=0.090;P=0.050);播放狼声音1min加空白5min防控效果有显著下降趋势(P=0.003);按顺序播放东北虎声音加野猪惨叫1min加空白5min组防控效果呈显著上升趋势(P=0.001),但防控有效期较短为(13.67±2.62)d,不具推广意义。因此,野猪危害防控措施中播放东北虎声音、综合使用东北虎声音和东北虎粪便、太阳能警示灯等均具有空间推广性和时间延续性。 相似文献
997.
Supawat Khaewphakdee Achara Simcharoen Somphot Duangchantrasiri Vijak Chimchome Saksit Simcharoen James L. D. Smith 《Ecology and evolution》2020,10(11):5152-5159
The primary prey of tigers across much of South‐East Asia has been depleted, reducing the ability of already limited habitat to support tigers. To better understand the extent to which two of the largest prey species, gaur (Bos gaurus) and banteng (Bos javanicus), contribute to the tiger's diet, we estimated the average size of these species killed by tigers. This information is needed to more accurately calculate biomass of these species in the tiger's diet and to devise strategies to increase tiger carrying capacity where habitat is fragmented and limited in west‐central Thailand. We used temporally clumped locations of 24 satellite radio‐collared tigers to identify their kill sites and obtained mandibles from 82 gaur and 79 banteng. Kills were aged by teeth eruption sequence, sectioning the M1 molar and counting cementum annuli. Of all gaur killed, 45.2% were adults; of all banteng killed, 55.7% were adults. The average weight of banteng killed was 423.9 kg, which was similar to the 397.9 kg average weight for gaur. The mean weight of both prey species is 3.5–4.5 times greater than the predicted 1:1 preferred prey to predator ratio. In the absence of medium‐sized prey, killing these larger animals may be especially critical for female tigers provisioning nearly independent young when male offspring are already larger than the mother. This is the first study to present data on the average weights of gaur and banteng killed in South‐East Asia, and these results suggest that these are key prey species to target in tiger prey recovery efforts. 相似文献
998.
热带岛屿生物多样性是全球生物多样性保护研究的热点之一。海南岛是中国面积最大的热带岛屿, 丰富独特的淡水蟹类是维持岛内淡水生态系统功能完整性的关键类群。本文通过多年野外调查, 综合历史及最新文献资料, 对海南岛淡水蟹类物种多样性及其现状进行调查和评估, 并对淡水蟹类物种多样性保护现状进行了分析讨论。研究发现, 海南岛淡水蟹类物种多样性分布中心位于中南部山地, 主要集中于中部的霸王岭、鹦哥岭和猕猴岭, 南部的五指山和吊罗山, 以及西南部的尖峰岭一带。其物种多样性整体上呈现中南部山地高、平原台地低的特点。根据《IUCN物种红色名录濒危等级和标准》对海南岛淡水蟹类物种现状的评估结果显示, 全岛受威胁淡水蟹类物种的占比为16.7%。基于分布区预测, 以海南热带雨林国家公园为主体的保护地对淡水蟹类潜在适宜分布区的覆盖度明显优于此前碎片化的各级保护区。本文研究结果显示, 海南岛淡水蟹类的总体生存状况良好, 但一部分山地或平原种类处于受胁状态。国家公园体制的建立有望为岛内淡水蟹类物种多样性保护提供前所未有的机遇。基于物种多样性分布格局开展淡水蟹类等淡水生物多样性监测, 有助于促进海南岛淡水生态系统完整性的长效保护与可持续发展。 相似文献
999.
Susan Anyango Oginah Paul O. Ang’ienda Patrick O. Onyango 《African Journal of Ecology》2020,58(1):34-45
We carried out a postrelease evaluation to determine predictors of habitat use and carrying capacity for the black rhinoceros (Diceros bicornis michaeli), which are critical for monitoring how the Ruma National Park sub-population may contribute to Kenya's meta-population strategy. We determined whether level of elevation, rockiness, shade, distance to fence, roads, and human settlements predict habitat use, differences in habitat and diet preference between female and male black rhinoceros, and the ecological carrying capacity (CC) of black rhinoceros in the park. We used standard ecological methods to collect data on predictors of habitat use, habitat preference and to estimate CC. Results show, first, that none of the environmental and anthropogenic factors evaluated predicted habitat use by black rhinoceros in the park. Second, although there was no significant difference in habitat preference between the sexes (U = 16.50, p = 0.306), there was a 60% difference in Jaccard's dissimilarity in diet selection between the sexes. Third, the park can support 65 black rhinoceros. Altogether, the findings suggest that the park has potential to support other sub-populations in Kenya. We recommend that future similar studies should incorporate population viability analysis and a community-based approach to forecast the species health and extinction risk. 相似文献
1000.
The fish rotan, Perccottus glenii Dybowski, 1877 (Odontobutidae) is one of the most successful fish invaders during 20th and beginning of 21st century in European and Asian fresh waters. The diversity of its parasites within its invaded range was first reviewed by Sokolov, Reshetnikov, et al. (2014). The current paper analyzes new data from 2013 to 2019 on protistan and metazoan parasites of the non-native populations of this fish. We used information from peer-reviewed journals, difficult to access grey literature and our own recently obtained original data. 45 literature sources were included in the analysis. The newly-available data originate from 95 water bodies of 13 river basins, isolated lakes in West Siberia, and Gulf of Finland, spanning a total of eight countries. A total of 132 recently detected parasite species/taxa are listed in this paper. Each species is presented with its location in/on the host, geographical localities, countries, and according literature sources. When available, number of examined fish as well as prevalence and range of intensity of infection are cited from the original source. This review enlarges contemporary knowledge on parasites of non-native populations of the studied fish species up to 167 species/taxa. We highlight perspectives for further parasitological investigations of this invasive fish. 相似文献