The activity patterns of Ommatoiulus moreletii (Diplopoda: Iulidae) in South Australia

Pitfall traps were set and visual observations made along regularly walked transects to assess the patterns of surface activity of Ommatoiulus moreletii in open grassland and dry sclerophyllous woodland in South Australia. Active O. moreletii were most commonly seen and trapped in autumn, to a lesser extent in spring, occasionally in summer and rarely in winter. Day to day variations in activity were related to changes in temperature and moisture. The activity of older stadia was greater than that of younger stadia.     

The post-embryonic development and life history of the millipede, Ommatoiulus moreletii (Diplopoda: Iulidae), introduced in south-eastern Australia

The life cycle of Ommatoiulus moreletii consists of an egg, pupoid and up to sixteen stadia. Sexes are differentiated at the sixth stadium. Males may mature at any moult from the eighth to the twelfth stadia, but most are mature by the tenth or eleventh. Maturation is more difficult to determine in females but seems similar to the males with respect to stadial age. O. moreletii is periodomorphic.
Field studies were made of O. moreletii in an open grassland and a dry sclerophyllous woodland in South Australia. Females matured their eggs in late summer-autumn. They mated and oviposited during autumn-winter. After one year, O. moreletii was in the seventh, eighth or ninth stadium. After two years, the tenth or eleventh stadia were reached and after three years the twelfth or thirteenth. The moulting of individuals older than about one year was confined to moults in (1) spring and (2) summer. Adult males were mature from summer to spring and intercalary from spring to summer.     

The water and temperature relationships of Ommatoiulus moreletii (Diplopoda: Iulidae)

During summer, Ommatoiulus moreletii aggregates in cool, moist sites. O. moreletii prefers high relative humidities and temperatures of 20 to 25°C throughout the year. These preferences explain the summer aggregations.
O. moreletii develops a strong ability to survive exposure to low humidity and high temperature during summer. This may explain why summer mortality of the millipede has only been demonstrated during an extremely hot and dry summer. The percentage water contents of O. moreletii are higher during spring and summer than during autumn and winter. They are also higher in small animals than in large. The ecological and physiological significances of these facts are discussed.     

北方地区典型林草地物候时空变化特征及其对气象因子的响应

为探究北方地区典型植被林地、草地物候特征及其对气候变化的响应,本文基于1982—2015年的GIMMS NDVI 3gv1数据集和气象资料,采用动态阈值法提取植被物候,应用线性回归和偏相关分析法分析林、草地物候时空变化特征及其与气候变化的关系。结果表明：(1)林地生长季长度(LOS)以0.32d/a的速率极显著延长,整体表现为生长季始期(SOS)以-0.18d/a极显著提前,生长季末期(EOS)以0.14d/a极显著推迟。林地SOS提前、EOS推迟和LOS延长的区域面积占比分别为93.3%、90.4%和96.3%。(2)草地LOS以-0.01d/a的速率不显著缩短,表现为SOS以-0.09d/a不显著提前,EOS以-0.10d/a不显著提前。SOS提前、EOS提前和LOS缩短的区域占比为67.5%、69.1%和50%。(3)林地SOS主要受冬末春初的气温升高和降水增加而提前,EOS受夏季气温升高、秋季以及冬末春初降水增加而推迟。(4)草地SOS主要受春季气温升高和短波辐射减少而提前,EOS受秋季气温升高和短波辐射减少而提前,草地物候与气象因子的响应时长小于林地。     

Bird communities of dry forests and oak woodland of western Mexico

Bird species-richness and densities were studied in spring and autumn of 1991 and 1992 in dry forest and oak woodland in western Mexico. Classification of the vegetation resulted in the identification of six dry forest types: from thorn forests, dominated by Acacia , through broad-leaved tree forest (typical dry forest of western Mexico) and small-leaved tree forest to Ipomoea forest. Oak woodland and mixed woodland, which are a transition between dry forest and the more mesic oak woodland, formed two further forest types. In the study area as a whole, bird densities were higher in autumn, following the rainy season, than in spring, which is the dry season, and the beginning of the breeding season. Densities in the two autumns were very similar (mean 93 ± 7.8 birds per 2.8 ha) but differed significantly between spring 1991 (57 ± 2.2 per 2.8 ha) and spring 1992 (70 ± 3.2 per 2.8 ha), possibly due to unseasonal rain in 1992. In autumn, bird densities were highest in thorn forests and lowest in broad-leaved tree forests and oak woodland. In spring 1991, bird densities were highest in Prosopis thorn forest and mixed woodland, and lowest in oak woodland. Bird species-richness was low in oak woodland, in both seasons, and high in mixed woodland and Ipomoea forest in spring. Bird species composition between forest types was more similar in the spring than autumn. The spring similarity in species composition is explained by the presence of generalist species in times of food scarcity during the dry season, and by the homogeneity of the predominantly leafless vegetation. Comparison with the bird species composition of a dry forest in Venezuela and the Pacific coast of Mexico indicates that the sites in the present study have an intermediate number of species. Although the present study recorded a smaller number of bird species than on the Pacific coast, 16 were different, expanding the total for Mexican dry forest by 14% from 118 to 134.     

Trends in annual and seasonal survival of Pink-footed Geese Anser brachyrhynchus

Adult Pink-footed Geese Anser brachyrhynchus from the Svalbard breeding population were neck-banded and resighted in staging and wintering areas outside the breeding season 1990–1999. We estimated annual and seasonal survival using capture–recapture statistical models. Mean annual survival was 0.829, declining over the study period from 0.90 to 0.79. The annual cycle was partitioned into three periods: summer (1 April–30 September), including both spring and autumn migration, autumn (1 October–31 December), including most shooting, and winter (1 January–31 March). The parsimonious model selected to describe seasonal survival included a declining trend in summer survival, constant autumn and winter survival with lower survival in the severe winter of 1996, and an additive effect of sex on summer and winter survival. Monthly survival was highest during winter. Decreasing summer survival was the main contributor to the overall decline in annual survival, and was attributed mainly to increasing natural mortality on the breeding grounds. Mean annual survival based on the seasonal survival probabilities was 0.835 for females and 0.805 for males. The effect of sex was most pronounced during summer and remains to be explained.     

内蒙古阴山北部农牧区长爪沙鼠种群适应特征的比较研究

长爪沙鼠(Meriones unguiculatus)是内蒙古阴山北部地区主要的农牧业害鼠。有关它的生态学及其危害已有过一些报道(夏武平等,1956; 赵肯堂,1960;夏武平等,1966;夏武平等,1982; 秦长育,1984)。对于农作区和草原区种群的适应性差异迄今未见研究。     

Sex differences in habitat use by African elephants (Loxodonta africana) in the Okavango Delta,Botswana: is size really the deciding factor?

Many sexually dimorphic mammals show sexual segregation of habitat use. We studied habitat selection and use by male and female elephants in the Okavango Delta, and males of different ages and therefore sizes, to assess whether size was a driving force behind any sex differences in habitat selectivity. There was variation in habitat choices, with males preferring island vegetation and mopane woodland and avoiding grassland/floodplain and Terminalia woodland; females showed no selection for or against most habitats other than selecting for mopane woodland in the rainy season. Male habitat choice changed dramatically during the dry season, when resources were most limited and there was the least sexual difference in habitat selection. Females were more selective in the flood season, when access to resources was restricted. Contrary to other studies and the forage selection hypothesis, males showed greater habitat selectivity than females, but age, and therefore size, did not affect their habitat selection. Whilst our data suggested that males were superior competitors, we could not discount that females excluded males from preferred habitats. In the Okavango Delta, habitat selection by male elephants may be more dependent on social groupings, and hence the decisions of others, than individual size and energetic requirements.     

Differential habitat utilization by patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus) living sympatrically in northern Cameroon.

In order to obtain reliable evidence for differences in habitat preferences between two closely related savanna-dwelling primate species, namely, patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus), I collected data on vegetation and patterns of range use concurrently at a single study site, Kala Maloue, Cameroon, in a similar manner for a group of each species. Kala Maloue consisted of 64% grassland mostly dominated by Gramineae spp. and the rest was woodland. Tantalus monkeys showed preference for woodland, especially gallery forest, much more than did the patas irrespective of the season. Moreover, patas preferentially established their home range in grassland in the wet season. Interspecific and seasonal differences in habitat preferences could be interpreted on the basis of interspecific and seasonal differences in preferences for main food. In dry season, tantalus utilized water-containing areas at a frequency closely in proportion to the availability of such areas while the patas utilized water-containing areas more frequently than expected. This is because tantalus established a smaller home range along the river where water was never completely depleted throughout the dry season. Both the patas and the tantalus preferred woodland to grassland as sleeping sites possibly owing to predation avoidance. Both the daily travel distance per group weight and the home range size per group weight were greater for patas than for tantalus partly because of higher preference for grassland with low habitat quality in the case of patas. It is suggested, however, that high locomotive ability enabled patas to effectively utilize small and widely dispersed items of food such as grasshoppers and to explore areas with high availability of food and water and with preferable sleeping sites.     

蒸发需求干旱指数(EDDI)在辽宁省干旱识别中的应用

蒸发需求干旱指数(EDDI)是从大气蒸发需求(E₀)角度出发建立起来的一种多尺度的干旱指标,具有不依赖降水量、适用于各种下垫面类型的特点,具备在不同时间尺度捕捉水胁迫信号的能力。本研究基于1961—2018年辽宁省52个气象站气象观测资料,逐日估算E₀,按年、生长季(4—10月)、春季、夏季、秋季、冬季分别计算EDDI,分6个时间尺度识别近58年辽宁省干旱发生的年际变化特征。结果表明: 研究期间,辽宁省EDDI年际变化阶段性明显,多个时间尺度的EDDI呈两个高值集中期。在20世纪60年代,年、生长季、春季、秋季和冬季5个时间尺度的辽宁省平均EDDI高值区相对集中,这一阶段辽宁省发生干旱的年数多、程度重;除冬季外,2014—2018年是其他5个时间尺度的EDDI高值另一个相对集中的时段;1981—1982年,辽宁省的年、生长季、夏季、秋季的EDDI值偏高。1963—1965年(除夏季外)、1972—1973年(生长季、夏季)、1989—1990年(年、生长季、春季、冬季)、1997—1998年(年、生长季、夏季)、2004—2005年(春季、冬季)和2013—2014年(年、生长季、秋季)都发生了干-湿或湿-干逆转事件。1985—1987、1993—1995和2005—2013年,辽宁省存在明显的干旱空窗期。     

阜阳机场鸟类多样性及其危险性

2008年6月至2010年1月,对阜阳机场及其周围5种生境(草地、农田、城镇、湿地、林地)的鸟类进行调查,并对不同季节、不同生境的鸟类多样性进行分析.结果表明:本次调查共记录到鸟类122种,隶属于15目40科;阜阳机场夏、秋季的鸟类种数显著高于冬、春季,秋季鸟类密度显著高于其他季节,夏季的鸟类多样性指数、均匀度指数均高于其他季节;在阜阳机场及其周边的5种生境中,林地的鸟类种数、密度均显著大于其他生境,林地、湿地、农田的鸟类多样性较高;对阜阳机场鸟击最危险的鸟种是麻雀、白头鹎、家燕、家鸽、喜鹊、珠颈斑鸠、灰椋鸟等.     

Seasonal shifts within juvenile recruit sex ratio of Pampas mice (Akodon azarae)

Sex ratio (SR) variation of Akodon azarae juvenile recruits was analysed during 1985–86 on a Pampean grassland in central Argentina. Rodents were intensively live-trapped on a 0.81 ha grid. The SR (proportion of males) of the overall population did not differ significantly from evenness (0.49). In contrast, juvenile recruits (0.5–2.0 months of age) showed SR fluctuations according to their time of birth. SR was strongly female-biased among spring and autumn juveniles (0.13 and 0.33, respectively), while males were predominant (0.72) among the summer juveniles.
Social and demographic implications of these results are discussed in the framework of current SR theory. Spring female recruits should be selected for summer reproduction and autumn female recruits for winter survival and spring reproduction. The overwintered population was characterized by 1:1 SR and an age structure composed of males older than females. Most of these males had been recruited as juveniles during the summer. They also made up most of the resident male population in the spring. A selective allocation of energy by the mothers among their offspring is the mechanism proposed to explain the seasonal changes in SR, as pregnant females which gave birth to the summer recruits were in better physical condition than the mothers of both spring and autumn recruits. These results are consistent with the predictions of Werren & Charnov (1978), based on temporal overproduction of one or the other sex according to differential changes in the life-history expectations for both sexes.     

放牧和刈割对内蒙古典型草原大型土壤动物的影响

采用连续3年全季节放牧、3种季节性轮牧、秋季刈割和不利用对照6种处理, 研究了内蒙古典型草原大型土壤动物群落特征.调查在春、夏和秋3个季节进行,共捕获大型土壤动物597只,隶属于2门4纲11目,49个类群.结果表明: 全季节放牧导致土壤动物的个体密度、生物量和多样性降低;而刈割的影响相对较轻,土壤动物的个体密度、生物量和多样性甚至有提高趋势.3种季节性轮牧处理中,夏季和秋季放牧2次处理对土壤动物群落个体密度、生物量和多样性等指标的负面影响较轻.刈割管理对退化典型草原大型土壤动物群落的恢复较为有利;夏季和秋季放牧2次处理对大型土壤动物群落的负面影响较轻,是较理想的草地可持续管理措施.     

南亚热带退化植被重建中土壤动物群落变化

在广东省中部的鹤山市鹤山丘陵综合试验场,分别在草坡、松林、荷木混交林(荷混林)、马占相思林(马占林)和豆科混交林(豆混林)选取5块样地,分别代表5种处理方式(重建植被类型)。在2003~2004年的4个不同季度内分3层取土样,利用Tullgren干漏斗法采集土壤动物,并分析土壤动物群落个体数量、类群丰度和DG指数的变化。研究结果表明,季节、植被类型和土层深度对土壤动物群落的各项指标都有极显著影响(P<0·01,three-way-ANOVA):土壤动物群落指标,在秋季显著为高(P<0·05,DMRT),而夏季显著为低(P<0·05,DMRT);随土层加深而逐级显著降低;不同植被类型比较,豆混林>马占林>荷混林、松林和草坡。此外,植被类型还与季节和土层间存在显著的交互作用:土壤动物群落各项指标秋季最高,不同植被类型间的差异也最大;而土壤动物群落各项指标较高的植被类型内不同土层间的差异也较大。由此推测,对退化生态系统进行人工改造是有积极意义的,而不同植被类型间土壤动物的差异可能与凋落物的数量与质量密切相关。     

Some population dynamics of the Bank vole, Clethrionomys glareolus and the Wood mouse, Apodemus sylvaticus in mixed woodland

The population dynamics of Clethrionomys glareolus Schr.and Apodemus sylvaticus (L.) in mixed woodland in County Durham, were studied from March 1963 to January 1965. Two areas of 0.9 ha (2.25 acres) each were trapped monthly and information was obtained on population size, reproduction, survival and growth from marked animals.
Clethrionomys populations increased from June to an autumn peak; then declined, at first rapidly, but then more slowly in winter, before reaching a spring trough. The breeding season of Clethrionomys was from May to December; juveniles were caught from mid-June to December. Survival was in general poor during the breeding season but good at other times. Survival of young born early in the summer was particularly good on one of the areas and some individuals lived long enough to breed in two successive years. On both areas young born early in the year matured rapidly and bred in the year of their birth. Young born in late summer and early autumn ceased growing at a weight of about 14.5 g, remained immature, and formed the bulk of the overwintering population. Growth was completed at the time of sexual maturation the following spring.
Trapping failed to provide adequate samples of juvenile Apodemus in summer to account for subsequent recruitment. The possibility that a substantial proportion of the adult population of this species was also either trap shy or had emigrated temporarily is discussed. Breeding occurred from April until the following January, but the numbers trapped remained very low throughout the early months of the breeding season. Large scale recruitment of young fecund animals into the trap-revealed population occurred during the autumn. Apodemus males continued to grow rapidly during the winter.     

Quantifying the damage of red deer (Cervus elaphus) grazing on grassland production in southeastern Slovenia

The influence of red deer (Cervus elaphus) grazing on grassland production for forage conservation at the forest border during the vegetation period was studied on three locations (Mala gora, Cvišlerji, and Mačkovec) in the Kočevje region (SE Slovenia). The experiment lasted from the 25th of March until the 8th of October 2002. Portable cages were used to exclude red deer from grazing the herbage. At four sampling dates in the season, herbage air dry matter (DM) yield was measured at three different observations (cage-protected plot, cage-protected plot only two to three weeks before sampling date, otherwise freely grazed (removed), and unprotected plot). The results from the experiment showed that red deer grazed on grassland through the entire season and that the regeneration capability of sward was the highest in summer, middle in spring and smallest in autumn. On unprotected plots, an average reduction of 50% of herbage DM yield was found with the most damaged sites also up to 80% reduction.     

Demographic and environmental causes of the decline of rural Song Thrushes Turdus philomelos in lowland Britain

We review current knowledge of demographic mechanisms and environmental factors implicated in the population decline of Song Thrushes Turdus philomelos in rural Britain since the mid-1970s, and present new analyses of regional variation in population changes. Increased mortality during the first year of life (from fledging to recruitment) is highlighted as a potential demographic mechanism having driven the population decline, while Song Thrushes in a rapidly declining farmland population were making too few nesting attempts to sustain local numbers. Breeding Song Thrushes are strongly associated with non-cropped habitats such as woodland edge, field boundaries, gardens and scrub; they make substantial use of grassland, but avoid cereals when foraging. Earthworms constitute a key component of Song Thrush diet and the availability of this prey is strongly influenced by moisture levels in surface soils. Several lines of evidence suggest that dry surface soils during summer are deleterious to the productivity and survival of Song Thrushes, and regional variation in the rates of population change in Britain during 1970–86 was negatively correlated with the extent of under-field drainage on farmland (the main function of which is to promote the drying of surface soils). Increasing dryness of agricultural soils and the loss of grassland from eastern arable counties have probably both contributed to the declines of rural Song Thrushes in Britain. Loss of hedgerows and scrub, and the degradation of woodland may also have contributed to population declines but the role of predators remains unclear. Recovery of rural Song Thrush populations requires challenging new policy initiatives that should aim to restore nesting cover (scrub and woodland understorey), grazed grassland in arable-dominated areas and damper soils in summer.     

For everything a season: Smoke-induced seed germination and seedling recruitment in a Western Australian Banksia woodland

Abstract The influence of factors associated with fire on seed germination of Australian native species is generally well documented, but examples involving the use of smoke as a fire analogue for ecological research remain limited. The role of season of treatment in the efficacy of smoke as a promotive germination agent was investigated over two growing seasons using natural soil stored seedbanks in Banksia woodland near Perth, Western Australia. Smoke was applied to unburnt sites in the autumn, winter and spring of 1994. Germinant emergence and seedling survival of 37 species representing 18 families was monitored in both unburnt sites and in adjacent, recently burnt sites until the second spring after treatment (October 1995). Recruitment from seed was found to be profoundly affected by the season in which dormancy breaking treatment had been applied. The promotive effect extended beyond the initial year of application. For the majority of the species investigated, application of smoke to unburnt sites in autumn promoted a significantly greater germination response than treatment in winter or spring. In only three cases (introduced annuals, the Fabaceae and Hibbenia amplexicaulis) did autumn smoke treatment not yield better germination than in summer-burnt counterparts. However, in almost half of the cases examined, proportions of seedlings surviving past their first summer after emergence in burnt areas were consistently greater than those in smoked or untreated sites. Most notably, no seedlings emerging during the spring of the first year of study survived into the following summer. Implications of the results with respect to future seed bank research and management of native vegetation are discussed.     

The population ecology of Rattus exulans on Tiritiri Matangi Island,and a model of comparative population dynamics in New Zealand

Abstract

On Tiritiri, a small predator-free island in northern New Zealand, kiore (Rattus exulans) were live and snap trapped in grassland and forest. In both habitats, kiore abundance peaked in late summer/autumn. The increase followed a 3 month breeding season during which females produced two to three litters, each averaging 7 young. During the population decline in autumn and winter, animals lost weight. Few bred in the breeding season of their birth and none lived to breed in a second breeding season, so the population consisted of distinct age cohorts. These patterns may relate to a highly seasonal food supply.

Kiore elsewhere in New Zealand show seasonal breeding, but the length of breeding, sexual maturation, and litter size vary. Other studies of kiore in the Pacific show less marked seasonal fluctuations, longer breeding seasons, and smaller litters. We propose a model to explain the variation in rodent demography in New Zealand. The model is based on the seasonal availability of food, along with the modifying influences of predation and dispersal.     

毛乌素沙地沙丘土壤含水量特点——兼论老固定沙地上油蒿衰退原因

土壤表面干沙层在冬春少雨季节较厚,流动沙地的又明显地大于固和地的。流动沙地地表干沙层以下的土壤含水量一般在于同深化度固定沙地的,特别是在报系密集分布的土层。科季或早春土壤含水量比较低,雨季的明显较高,雨季结束后,土层中的水分在重力的作用下会向深层运动,导致根系层土壤含水量下降。在植物生长季,缺少降雨时,因少地的土土壤水量会因植物的蒸腾消耗而变得很低（１％～２％）,而流动沙地的不受或受此影响很小。地