A comparison of some range condition assessment techniques used in southern African grasslands

Techniques currently used to assess range condition in the grassland biome of southern Africa are reviewed. The methods were used to calculate range condition indices from fire‐climax and climatic‐climax grassland data. These indices were then used to evaluate each method in terms of sensitivity (i.e. the detection of spatio‐temporal differences in index), index interpretation and efficiency, bearing in mind the objectives of each technique. The Weighted Key Species Method and Degradation Gradient Method were found to currently provide the best indices for assessing range condition. Shortcomings of the techniques are recognized and suggestions are made for the application of these methods in different vegetation types.     

Relative brain size and morphology of some South African bats

Measures of relative brain size and brain macromorphology are described for four species of Microchiroptera, two from the Vespertilionidae and two from the Rhinolophidae, and two species from the Pteropodidae (Megachiroptera). Four brain parameters (brain length, hemisphere length, brain width and brain height) were measured, and converted to indices of proportion to allow interspecific comparison. The megachiropteran species have relatively larger brains than the microchiropteran species, this being primarily a result of the greater development of the cerebral hemispheres in the former group. Of the microchiropteran species, Miniopterus schreibersii has the highest value for comparative brain size and its brain shows several characteristics of the more encephalized Megachiroptera such as reduced exposure of the mesencephalic tectum, and the presence of prominent cerebral sulci. The possibility that the differences in brain size and development between the Megachiroptera and the Microchiroptera, may be related to diet, or that they may be of phylogenetic origin, is discussed.     

海拔梯度对藏北高寒草地生产力和物种多样性的影响

草地群落物种多样性和生产力在海拔梯度的变化规律及其关系, 以及不同功能群的变化一直是热点问题, 目前尚未得出一般性规律。本研究通过藏北地区那曲县日参波山样线的高寒草地样方调查实验, 分析各海拔梯度(4485~4635 m)植物群落生产力、结构和物种多样性的变化。结果表明, 随着海拔升高, 高寒草地植物群落生产力先增加后降低, 并在海拔4535~4585 m左右达到最佳;莎草类在群落由相对优势变为绝对优势, 禾草类和杂草类的重要值以不同幅度下降, 豆科类的重要值先上升后下降;物种丰富度、Shannon-Weiner 多样性指数、Simpson多样性指数和E.Pielou均匀度指数均呈现“单峰”型格局, 物种多样性指数与地上生物量呈正相关关系, 但只能作为部分解释地上生物量变化的因素。     

春季草坪害虫群落种类丰富度与多样性研究

研究是 2 0 0 0年 4 6月在董志塬进行的。研究结果证明 :草坪害虫群落种类丰富度和多样性指数分别为 2 0 .514和 4 .0 2 2 ,而当地冬麦麦田的对应指标分别是 11.357和 1.0 2 7。进一步分析了产生这种差异的原因     

Comparative foraging behaviour of three species of shrike in southern Africa

Utilisation of food resources in migrant and resident birds living sympatrically often leads to differences in feeding strategy. For sit-and-wait hunters such as shrikes, it is connected with competition for food and hunting places. In this study, foraging behaviour of three shrike species was studied in savanna-like habitat in southern Africa. The fieldwork was carried out in December 2017 during wintering season of Lesser Grey Shrike Lanius minor and Red-backed Shrike Lanius collurio and breeding season of Common Fiscal Lanius collaris. Details of the bird's behaviour were recorded during 30 min observations of each bird. A general linear mixed model with logit link function and binomial error variance was used to compare the species’ behaviour. Although the type of perch-site and perching time did not differ between species, Red-backed Shrike used places situated significantly lower than other shrikes. This species also more often used bushes and attacked from lower perch-sites than Lesser Grey Shrike. This may possibly be due to interspecific competition and antipredator behaviour of Red-backed Shrike. No differences in foraging behaviour between Common Fiscal and Lesser Grey Shrike were observed. All three species utilised the same category of prey. Hunting success (the ratio of successful to all attacks) was low and similar in all three species (47%–57%). The lack of statistically significant differences in behaviour, hunting success and size of prey items among shrike species may be a consequence of the relatively short observation time and small sample sizes.     

藏北高寒草地植物群落物种多样性沿海拔梯度的分布格局

以藏北地区那曲县日囤布山的高寒草地为研究对象,采用样方调查法,分析不同海拔高度（4 523~4 673 m）草地植物群落结构及物种多样性的变化格局。结果表明,随着海拔的升高,高寒草地植物群落总盖度与地上生物量均表现出先增加后降低的趋势,即在中等海拔梯度（4 623 m）水平草地植被生长最好;不同海拔梯度间植物物种组成存在很大的差异;植物群落物种丰富度、Shannon Wiener多样性指数和E.Pielou均匀度指数,呈现“单峰”分布格局,中海拔梯度处物种丰富度最高。     

不同海拔关山草原群落的结构特征

以不同海拔梯度下（坡下、坡中、坡上）陕西关山草原群落为研究对象,利用幂乘方法则分析植被的空间分布特性及其群落的物种组成、物种多样性等。结果表明,坡下、坡中、坡上3个不同海拔梯度下,草地群落的组成物种对幂乘方法则具有很好的吻合性;草地群落的总物种数、物种多样性指数(H′)及群落整体的空间异质性指数（δc）都随海拔梯度的升高而增加;样方内的平均物种数、平均多样性指数亦随海拔梯度的升高而增加,但它们之间没有显著性差异（P>0.05）;坡上、坡中禾本科和豆科植物的出现频率较高,而草地退化的标志性植物火绒草（Leontopodium leontopodioides）在坡中的出现频率很高,蛇莓（Duchesnea indica）和毛茛（Ranunculus japonicus）在坡下的出现频率更高,表明坡下草地退化比较严重。     

Polystomatidae (Monogenea) of southern African Anura: Polystoma channingi n.sp. parasitic in two closely related Cacosternum species

Polystoma channingi is described as a new species of polystomatid flatworm (Monogenea) parasitic in the urinary bladder of Cacosternum nanum in the Eastern Cape Province, South Africa. In a locality where C. nanum and C. boettgeri occur sympatrically the parasite has been found in both species. This finding of a Polystoma sp. in two closely related host species questions the strict host-specificity generally ascribed to the genus, but supports the hypothesis that host-specificity is determined by the oncomiracidium's ability to recognize the tadpole as a suitable host. This is the first polystome to be described from the genus Cacosternum and the ninth species of Polystoma from South Africa. The species is distinguished by its huge haptor and suckers relative to the body size. The haptor length/body length ratio of 0.38 is by far the largest for the known southern African polystomes. The prevalence of infection with P. channingi n.sp. was 25% for C. nanum and 40% for C. boettgeri, while the mean intensity of infections in adult frogs was 1.5 for C. boettgeri and 1.0 for C. nanum.     

气候变暖和物种多样性交互效应对空心莲子草入侵的影响

全球变暖加剧了生物入侵进程,而物种多样性对于入侵物种通常具有阻抗作用,探讨二者交互效应对生物入侵的影响有助于预测入侵态势及制定有效的防治措施。通过在我国N 21°-37°设置59个调查样地,探讨外来入侵植物空心莲子草群落物种多样性与其入侵态势之间的关系;并采用人工构建群落的方式,设置不同温度、物种多样性组合两种因子,研究增温及本土植物多样性对空心莲子草入侵的影响。结果表明:1)样地群落的Shannon-Wiener多样性指数介于0~2.434,空心莲子草入侵盖度(P<0.001)、分枝数(P=0.022)随多样性上升而显著降低,纬度以及纬度×物种多样性交互效应对其入侵态势没有产生显著影响;2)增温导致构建群落中空心莲子草的高度(P=0.004)、最大茎长(P=0.002)以及马唐、苦苣菜和牛筋草3种本土植物的高度(P=0.038)均显著下降,物种多样性上升导致空心莲子草高度、无性分株数、分枝数和最大茎长均显著下降(P<0.001),增温×物种多样性交互效应导致空心莲子草分枝数在“入侵单种”处理中显著升高(P=0.035),而增温×物种属性交互效应显著降低了构建群落中苦苣菜的最大茎长(P<0.001);3)增温并未显著影响空心莲子草及本土植物生物量,物种多样性增加显著削弱了空心莲子草的生物量(P<0.001),但显著提高了其根冠比(P=0.014),即空心莲子草以相对储存更多地下资源的方式应对种间竞争。综上可知,较高水平的物种多样性有助于抵制空心莲子草的入侵,但增温可能会削弱本土物种的抗性;气候变暖背景下应更加重视保护本土植物多样性,以遏制空心莲子草入侵蔓延。     

Distribution pattern of endangered bird species in China

In this study, we determined six “hotspots” for avian biodiversity conservation in China. We analyzed the distribution patterns of 183 threatened bird species in China in conjunction with geographical data to produce a distribution map that shows the concentrations of threatened species. The six biodiversity hotspots are: the western Tianshan Mountains; the Qilian and Hengduan mountains; southern Anhui, southern Jiangsu, and the Zhejiang Hills; the Songliao Plain and the northern region of the North China Plain; the island of Taiwan; and the island of Hainan. Based on our analysis of a species–habitat matrix, species were determined to be distributed mainly in broadleaved forest, grassland and meadows, urban and agricultural areas, wetlands, and bush. Most species were commonly found to have a range of three to five different habitat types. Apart from the six biodiversity hotspots, six ecological clusters were determined. Protection strategies indicating different levels of habitat priority among the biodiversity hotspots were also recommended.     

Species identification and cow risks of non-aureus staphylococci from South African dairy herds

Detailed information on specific species of non-aureus staphylococci (NAS) has become a necessity for effective udder health control programs in South Africa. The main objective of this preliminary study was to identify the different NAS species and strains present in dairy herds in South Africa using a cost-effective method. A further objective was to investigate the effects of cow risk factors and farming systems on the NAS isolates identified. A total of 214 NAS, isolated from milk collected from 17 South African dairy herds, were identified using three diagnostic tests (API Staph test, MALDI-TOF and 16s rRNA). There was a good observed agreement between the MALDI-TOF and 16S rRNA sequencing (92.2%) and a poor observed agreement between the MALDI-TOF and API Staph (25.7%). The genetic relatedness within species was investigated in 128 of these isolates using random polymorphic amplified deoxyribonucleic acid (DNA) (RAPD), verified by multilocus sequence typing (MLST), and phylogenetic analysis and cow risk factors were investigated on species level. The main NAS species isolated were Staphylococcus chromogenes (75.2%), Staphylococcus epidermidis (9.4%) and Staphylococcus haemolyticus (8.9%). The RAPD test identified 34 Staphylococcus chromogenes, 13 Staphylococcus epidermidis and nine Staphylococcus haemolyticus strains, indicating genetic diversity amongst strains and herds. The presence of NAS intramammary infections was found to be significantly related to the farming systems, composite cow milk somatic cell count (SCC), parity and days in milk (DIM). Significantly more NAS were isolated from primiparous and from older cows. This knowledge could assist with the management of NAS on dairy farms.     

黄河兰州段湿地典型植物群落物种多样性研究

以黄河兰州段分布最广泛的芦苇-假苇拂子茅群落和酸模叶蓼-灰绿藜群落为研究对象,研究2个群落的植物物种组成和多样性特征。结果表明:芦苇群落有植物22种,隶属于13科20属,酸模叶蓼群落有植物24种,隶属于11科22属,2个群落的共种有10种,相似性系数为43.48%,菊科、禾本科、藜科、蓼科是该植物区系的优势科。物种多样性的分析说明2个群落的Pielou指数(J)波动比较小,Simpson指数(D)和Shannon-Wiener指数(H)均波动都比较大,并且H指数与J指数存在明显的正比例关系,而与D指数呈显著的反比例关系。方差分析表现出两群落S,H,D和J指数的差异并不明显,说明组成两群落的物种有一定的相似性和连续性,也存在着差异。     

复合微生物肥料对羊草草原植物群落物种多样性和生物量的影响

为了解草原植物群落物种多样性和植物地上生物量对施加复合微生物肥料的响应,在内蒙古呼伦贝尔羊草草原,分别设置对照(CK)、单施腐殖酸复合微生物肥料(F)、蜜糖发酵复合微生物肥料(T)、海藻酸复合微生物肥料(H)、3种复合微生物肥料混合施入(F+T+H)、腐殖酸加菌剂复合微生物肥料(F+J)和海藻酸加菌剂复合微生物肥料(H+J)7个处理,研究复合微生物肥料对草原群落植物物种多样性和植物地上生物量的影响。结果表明:(1)与对照组相比,2014-2016年施加F、H植物群落特征无明显变化,施加F+T+H植物群落密度分别增加了26.72%、17.94%、34.64%,地上生物量分别增加了7.18%、49.97%、47.64%,其他施肥处理群落特征各年变化不同;(2)2014-2016年施加F植物群落主要物种的重要值无明显变化,施加 T、H、F+T+H、H+J禾本科、豆科植物重要值增加,根茎型禾草(羊草等)对复合微生物肥料添加的响应显著高于丛生型禾草和莲座型菊科植物等草类;(3)2014-2016年施加F, Margalef指数分别比对照组减小了16.40%、5.22%、37.22%,施加H各指数无明显变化,施加F+T+H, Margalef指数、Shannon-Wiener指数、Pielou指数均增加;2014和2015年施加H+J 的Pielou指数分别比对照组增高了7.62%、8.70%。上述结果说明,施加复合微生物肥料对羊草草原植物群落物种多样性和植物地上生物量有显著的影响,其中F+T+H植物群落物种多样性和植物地上生物量显著增加,此外还应充分考虑施肥年降水量,从而实现对草地资源的合理修复。     

Effect of short-duration overnight cattle kraaling on grass production in a southern African savanna

Ranch owners in eastern and southern Africa have embraced a new rangeland management practice of keeping cattle overnight in temporary livestock corrals (hereafter referred to as kraals) within rangelands for short durations (for example, one week) to improve grass production. To better understand the influence of this practice on the grass community, we determined grass species diversity, richness, biomass and quality (crude protein, fibre, rumen fermentation and metabolisable energy) from a chronosequence consisting of kraals abandoned 1, 2, 3 and 4 years prior to the study and compared them to the surrounding vegetation. Grass species diversity, richness, biomass and quality were higher in abandoned kraals than the surrounding vegetation. Grass biomass increased five-fold in the first year of kraal abandonment and thereafter declined three-fold after four years. Metabolisable energy, a measure of grass nutritive value, increased from 8.92 to 11.90 MJ kg?1 with kraaling. The number of grass species also increased with kraaling. Palatable grass species, such as Urochloa mosambicensis and Panicum maximum, were more abundant in abandoned kraal sites than the surrounding vegetation. We conclude that short-duration overnight cattle kraaling improves grass quality and biomass.     

云雾山本氏针茅草地群落恢复演替过程中的物种多样性变化动态

采用样方法对云雾山干草原区本氏针茅草地群落进行长期定位监测,对未封育样地和封育5,10,15,20和25年样地群落的平均高度、盖度、多度和地上生物量以及植物多样性进行实地调查分析,以研究围栏封育对草地植物群落特征动态变化的影响.结果表明,围封10年样地群落的高度、多度以及地上生物量最大,而群落的盖度则随封育年限的增加呈显著增加趋势,在封育25年达到最大;围栏封育的不同年限也显著影响了群落的物种多样性,在围封10年样地群落具有最高的多样性指数,围封15年样地具有最高的丰富度指数,而均匀度指数则是在未封育群落中表现为最高值,最低值是在物种丰富度最高时出现.由此可见,围栏封育在一定时间范围内可以显著改善群落的特征,增加群落的生产力,对于本研究地本氏针茅群落的最佳封育期限为10～15年,但围封时间过长在草地退化方面有一定程度的影响.     

小五台山亚高山草甸的群落特征及物种多样性

采用样带和样方相结合的方法沿海拔梯度取样,利用数量生态学方法对小五台山国家级自然保护区亚高山草甸群落进行分析。结果表明,1)双向指示种分析(TWINSPAN)将该区的草甸群落分为9个类型;2)RDA排序结果较好地反映出群落分布格局与环境梯度的关系,各个群落类型在前两轴分异明显;第一轴反映了群落分布格局与坡向、土壤温度、海拔、土壤厚度极显著相关(P0.01),与土壤湿度显著相关(P0.05);第二轴反映了群落分布格局与坡度、土壤厚度极显著相关(P0.01);3)环境因子的蒙特卡罗随机置换检验表明,坡向、海拔、坡度显著影响群落分布(P0.05),对植被类型的形成具有关键作用;4)草甸群落Patrick丰富度指数随着海拔的升高呈下降趋势,随着坡向值的增加、土壤温度的升高呈逐渐上升趋势;Shannon-Wiener多样性指数随土壤厚度的增大呈微小下降趋势;Pielou均匀度指数随着海拔的升高、土壤湿度的增大呈上升趋势,随着坡向值的增加、土壤温度的升高呈逐渐下降趋势;Simpson优势度指数随着坡度的增大表现出微小的下降趋势,随土壤厚度的增大呈上升趋势。     

新疆不同草地类型植物物种特征与水热因子的关系研究

本文以新疆7种草地为研究对象,调查364个样地的物种名录,分析不同草地植物科属种的变化特征,探讨了植物物种丰富度(SR)对年平均温度(MAT)、降水(MAP)、海拔的响应。研究结果表明,新疆草地以禾本科、菊科为优势科,优势属为针茅属、绢蒿属;物种丰富度变化为:温性草甸草原(7.73)>温性草原(5.04)>高寒草原(4.36)>温性荒漠草原(3.99)>温性草原化荒漠(3.02)>温性荒漠(2.08)>低平地草甸(1.43);全部样地和温性草原的SR与MAP呈正相关,与MAT、海拔呈峰型关系;低平地草甸和高寒草原的SR与MAP呈正相关而与MAT呈负相关,与海拔呈先降低再增加的趋势;温性荒漠草原的SR与MAP呈正相关,与MAT、海拔无相关性;温性荒漠的SR与MAP呈正相关,与MAT呈负相关,与海拔呈峰型关系;温性草甸草原和温性草原化荒漠的SR与MAT、MAP均无相关性。不同草地类型对温度、降水响应的差异,是由于植被类型和温度、降水的空间分异性,对于海拔的分异,来源于海拔梯度范围和所研究地区大尺度的气候特征。     

放牧季节及放牧强度对高寒草地植物多样性的影响

在海北高寒草地进行了7年轻度放牧、中度放牧和重度放牧试验,并用围栏控制放牧进行对照.试验显示,物种丰富度和均匀度在夏季牧场和冬季牧场出现不同的变化.在夏季牧场,物种丰富度随着放牧强度的增强而增强,而均匀度则随着放牧强度的增强而下降;在冬季牧场,物种丰富度和放牧之间呈现驼峰反应模式,说明植物的丰富度在中度放牧强度时达到最大.不同牧场生物多样性变化的模式说明夏季牧场放牧强度不足.     

Effects of a fast-burning spring fire on the ground-dwelling spider assemblages (Arachnida: Araneae) in a central South African grassland habitat

Fire is widely used as a management strategy in grasslands to maintain vegetation structure and improve grazing quality for large herbivores. The impacts of burning on invertebrates in South Africa remain poorly understood. A study was initiated in spring 2005 to determine the impact of a fast hot burn on ground-dwelling spider assemblages in a grassland habitat in the central Free State. Pitfall traps were set out at six sites in the reserve, with three sites each in the burnt and unburnt areas, to sample spiders over a 12-month period. A total of 5 253 spiders were collected, representing 33 families and 120 species. Spider abundance was significantly lower in the burnt (n = 1 956) than unburnt sites (n = 3 297), and burnt sites had, on average, considerably fewer species than unburnt sites. The dominant families in the burnt sites were Lycosidae (29.5%), Gnaphosidae (16.9%), Ammoxenidae (9.6%) and Zodariidae (5.7%), whereas Ammoxenidae (22.7%), Lycosidae (20.6%), Gnaphosidae (15.3%) and Amaurobiidae (10.2%) dominated the unburnt sites. Of the nine most abundant families collected, only Caponiidae were more abundant in the burnt than unburnt sites. Our data suggest that fast-burning hot spring fires cause a considerable initial post-fire decline in spider abundance, and have a negative influence on the abundance as well as the resistance of assemblages to disturbances other than fire (e.g. rain). However, most of the dominant families had abundances comparable to unburnt areas within a year post-burn.     

城市化对杭州市繁殖鸟类物种多样性与功能多样性格局的影响

2007年3月至2007年8月,在杭州地区的城区、城乡结合区、农田区、农林交错区和自然林区等不同城市化程度的栖息地内各设置了90条100 m×3000 m调查样线,采用样线法对鸟类种类及其数量进行调查,采用实地调查与查阅文献相结合的方法确定每种鸟类的营巢类型和功能团,采用Shannon-Wiener指数计算鸟类群落的物种多样性和功能多样性.同时,对栖息地的人为干扰、植被盖度、人工设施指数等3项参数进行测定,并以此计算出各样线的城市化综合指数.调查结果显示,研究区内共记录有繁殖鸟类96种,分属于林冠枝干营巢功能团、灌草丛营巢功能团、林冠枝干/灌草丛营巢功能团、自然洞穴营巢功能团、人工建筑营巢功能团、自然洞穴/人工建筑营巢功能团、地面营巢功能团、水面营巢功能团和寄生功能团等9种功能团.对鸟类群落的物种数、物种多样性、功能团丰富度、功能多样性与城市化综合指数进行回归分析发现,城市化对鸟类群落的物种数、物种多样性、功能团丰富度和功能多样性均有着极显著性的影响,并且随着城市化程度的提高这些参数值均明显下降.不过,物种数和物种多样性与功能团丰富度和功能多样性间的下降模式存在明显差异.其中,物种数和物种多样性基本旱线性下降模式,即随着城市化程度的提高,物种丰富度及多样性基本为匀速下降;而功能团丰富度和功能多样性则呈二次函数下降模式,即在城市化初期,功能团丰富度和功能多样性下降不明显,但随着城市化程度的继续提高,功能团丰富度和功能多样性呈现加速下降的趋势.可见,鸟类群落的物种多样性和功能多样性对城市化的响应存在差异.虽然适度城市化可使物种多样性下降,但对功能多样性的影响却不明显;而群落的功能多样性则对高度城市化更为敏感.进一步对鸟类群落功能多样性与物种多样性的回归分析显示,功能多样性与物种多样性亦呈二次函数曲线关系,即在低多样性水平时,功能多样性与物种多样性基本呈线性关系,但随着多样性水平的逐渐升高,功能多样性的增长速度则明显慢于物种多样性的增长速度.由此可见,当群落物种多样性达到一定水平时,物种的增加不会明显地提高群落的功能多样性.