SPATIAL AND TEMPORAL ABUNDANCE PATTERNS OF WATERBIRDS IN THE SOUTHERN CAPE PROVINCE. PART 2: WATERFOWL

Boshoff, A.F., Palmer, N.G. & Piper, S.E. 1991. Spatial and temporal abundance patterns of water-birds in the southern Cape Province. Part 2: Waterfowl. Ostrich 62:178-196.

Waterfowl (ducks, geese, moorhens, gallinules, coot) were counted, and water-level and water transparency measured, on a monthly basis from 1980 to 1983 or 1984, at the six waterbodies comprising the Wilderness-Sedgefield Lakes Complex, southern Cape Province. The fluctuating status of the submerged aquatic macrophytes, and the trophic status of the waterbodies, was documented. The counts reflect the monthly status o the birds, and allow the calculation of densities (birds/ha). Linear and logarithmic models aided the interpretation of the count data. Spatial and temporal patterns and trends are described, and discussed in relation to changes in water-level, water transparency and aquatic macrophyte biomass regimes in the study area. Cyclical fluctuation in Potamogeton pectinatus biomass, and Its effect on Red-knobbed Coot numbers, is emphasised. The monthly abundance peaks of some species occurred at water-bodies in a regular sequence each year.     

SPATIAL AND TEMPORAL ABUNDANCE PATTERNS OF WATERBIRDS IN THE SOUTHERN CAPE PROVINCE. PART 1: DIVING AND SURFACE PREDATORS

Boshoff, A.F., Palmer, N.G. & Piper, S.E. 1991. Spatial and temporal abundance patterns of water-birds in the southern Cape Province. Part 1: Diving and surface predators. Ostrich 62:156-177.

Diving and surface feeding waterbirds (grebes, cormorants, gulls, terns, kingfishers) were counted, and water-level and water transparency measured, on a monthly basis from 1980 to 1983 or 1984, at the six waterbodies comprising the Wilderness-Sedgefield Lakes Complex, southern Cape Province. The fluctuating status of the submerged aquatic macrophytes, and the trophic status of the waterbodies was documented. The counts were considered to be reasonably accurate, allowing the calculation of densities (birds/ha). Spatial and temporal patterns and trends are described and discussed; linear and logarithmic models aided the interpretation of the data. Some species exhibited significant correlations with water-level and/or water transparency, and some exhibited abundance peaks at the waterbodies in a regular monthly sequence. Possible reasons for these phenomena are discussed.     

RELATIVE ABUNDANCE OF CRANES (GRUIDAE) IN THE CAPE PROVINCE

Siegfried, W. R. 1985. Relative abundance of cranes (Gruidae) in the Cape Province. Ostrich 56:101-103.

The results of monthly roadside counts of Crowned Cranes Balearica regulorum, Wattled Cranes Grus carunculatas and Blue Cranes Anthropoides paradisea show that Blue and Crowned cranes occurred most abundantly and densely in the eastern part of the Cape Province in 1965–1966. The Blue Crane's average relative abundance was approximately four times that of the Crowned Crane whose population occupied tend to breed in summer, the Blue Crane slightly earlier than the Crowned Crane. The population of the Wattled Crane was a small relict, occurrin in East Griqualand. Based on a rough estimate, there were about 1000–1500 Crowned Cranes and about 7000–10000 Blue Cranes in the Cape Province in the mid-1960s.     

SYSTEMATIC NOTES ON BIRDS OF THE CAPE PROVINCE

Hofshi, H., Gersani, M. &; Katzir, G. 1987. Urban nesting of Tristram's Grackles Onychognathus tristramii in Israel. Ostrich 58: 156–159.

Urban nesting of Tristram's Grackles Onychognathus tristramii is described. Nesting in the town of Arad, Israel, was first observed in the summer of 1983. Breeding behaviour was recorded during two seasons, in six nests. The behaviour of Tristram's Grackles resembled that of related Onychognathus species. The birds were monogamous. Breeding was from March to the end of June, and nests were built in holes and crevices in unoccupied buildings, 6–20 m above the ground. The nest was deep, cup shaped and built predominantly of green Tamarix branches. Three to four eggs were laid. Only the female incubated, while the male guarded. Both parents fed the young on insects fruit and human food remains. The nestlings remained in the nest for approximately 30 days. Parents continued to feed the fledglings for a week after they had left the nest. The fledglings formed juvenile flocks, two weeks after they had left the nest. The adults might then raise a second brood. The process of urbanization of the grackles is discussed.     

中国动物地理亚区繁殖鸟类地理分布格局与时空变化

以中国动物地理亚区统计了1976年郑作新出版的《中国鸟类分布名录》和2005年郑光美主编出版的《中国鸟类分类与分布名录》中繁殖鸟类的分布数据,结果显示:在1976年前,中国鸟类丰富度最高的动物地理亚区为西南山地亚区,其次为滇南山地亚区,而以羌塘高原亚区鸟类物种丰富度最低,黄淮平原亚区次差。2005年,鸟类丰富度最高、次高及最低的亚区与1976年相同,次差的亚区为台湾亚区。自1976年至2005年,鸟类物种丰富度在不同亚区出现明显的增加,平均每个亚区分布物种数由1976年的232种增至2005年的281种,而且具有很大的相关性;其中滇南山地亚区增加种类最多,而羌塘高原亚区和东部草原亚区增加的幅度最大;在海南岛和台湾亚区则变化较小。这些可能是由于物种在不同亚区间存在的可能扩散通道和岛屿型稳定气候及地理隔离限制了物种与其它亚区间的扩散等造成的。这些变化不仅与Leietal.(2007)提出的"地理隔离"假设结论比较一致,与雷富民等(2006)提出的西南山地-横断山区为中国鸟类特有种物种多样性中心和西南山地为物种分化中心等观点一致,而且进一步显示西南山地亚区鸟类物种有向滇南山地亚区扩散的现象,并且依然在持续中。用聚类...     

ASPECTS OF THE POPULATION DYNAMICS OF CAPE VULTURES IN THE CAPE PROVINCE

Robertson, A. S. 1984. Aspects of the population dynamics of Cape Vultures in the Cape Province. Ostrich 55: 196–206.

Information gathered in 1981 and 1982 and collated from previous records on the numbers, spatial distribution, proportion of age classes, age and frequency of breeding, breeding success and causes of breeding failure, and the survival of immature and adult Cape Vultures Gyps coprotheres in the southern and southwestern areas of the Cape Province, South Africa, is presented. This sub-population of about 75 birds is apparently isolated from conspecifics in the rest of southern Africa; the implications of this are discussed. At the Potberg colony in both years an average of 85% of birds 5 years and older were involved in breeding attempts. The age of first breeding was 4–6 years. Nest sites were active for about two in every three years. Between 1975 and 1982, 0,51-0,67 nestlings were reared per active nest site (n=165). Four (possible maximum six) of 21 immatures were resighted one year after they had flown. Of 123 birds that had been ringed at Potberg to 1980, 14 (11%) were sighted in 1981; only four of 48(8%) colour-ringed birds 5 years old and older were breeding in 1981.     

ANDROMONOECY IN ZIGADENUS PANICULATUS (LILIACEAE): SPATIAL AND TEMPORAL PATTERNS OF SEX ALLOCATION

I describe patterns of sex allocation and gamete packaging in the andromonoecious lily Zigadenus paniculatus. In this species, pistil length was continuously, but bimodally, distributed within plants, and smaller pistils contained fewer mature ovules. In hermaphrodite flowers, ovule number per flower increased with blooming rank in small plants but decreased with blooming rank in large plants. Flowers with pistils less than three-fourths stamen length almost never produced fruits and were classified as males. The pedicel, tepals, stamens, and pistil of hermaphrodite flowers were all heavier than those of males. Hermaphrodite flowers were concentrated on the terminal raceme, males on the lower racemes. In combination with acropetal blooming, this spatial separation of flower types resulted in a seasonal decline in the proportion of open flowers that were hermaphrodite. However, individual flowers were protandrous, so that the population sex ratio, initially strongly male-biased, declined as the season progressed. Hand pollinations showed that plants were self-incompatible. Inflorescence size was positively correlated with bulb size, and plants with large inflorescences had a higher proportion of male flowers. Nutrient supplementation had no effect on inflorescence size, but increased the proportion of hermaphrodite flowers. Nutrient-supplemented plants also began blooming earlier than controls. I discuss these patterns in relation to the adaptive significance of andromonoecious breeding systems.     

PHYTOPLANKTON ABUNDANCE AND COMPOSITION IN THE SOUTHERN OCEAN

The Russian research vessel Akademik Treshnikov, circumnavigated Antarctica in the summer of 2016–2017. The authors describe some of the findings of their research on phytoplankton, and contrast their voyage with that made by J.D. Hooker in 1839–1843.     

TEMPORAL AND SPATIAL PATTERNS OF SPECIFIC LEAF WEIGHT IN SUCCESSIONAL NORTHERN HARDWOOD TREE SPECIES

Temporal and spatial patterns of specific leaf weight (SLW, g/m²) were determined for deciduous hardwood tree species in natural habitats in northern lower Michigan to evaluate the utility of SLW as an index of leaf photosynthetic capacity. No significant diurnal changes in SLW were found. Specific leaf weight decreased and then increased during leaf expansion in the spring. Most species, especially those located in the understory, then had relatively constant SLW for most of the growing season, followed by a decline in SLW during autumn. Specific leaf weight decreased exponentially down through the canopy with increasing cumulative leaf area index. Red oak (Quercus rubra), paper birch (Betula papyrifera), bigtooth aspen (Populus grandidentata), red maple (Acer rubrum), sugar maple (A. saccharum), and beech (Fagus grandifolia) generally had successively lower SLW, for leaves at any one level in the canopy. On a given site, comparisons between years and comparisons of leaves growing within 35 cm of each other showed that differences in SLW among species were not due solely to microenvironmental effects on SLW. Bigtooth aspen, red oak, and red maple on lower-fertility sites had lower SLW than the same species on higher-fertility sites. Maximum CO₂ exchange rate, measured at light-saturation in ambient CO₂ and leaf temperatures of 20 to 25 C, increased with SLW. Photosynthetic capacities of species ranked by SLW in a shaded habitat suggest that red oak, red maple, sugar maple, and beech are successively better adapted to shady conditions.     

典型养殖湖泊大通湖软体动物的时空分布格局

研究于 2008 年 12 月至 2009 年 10 月按季度对大通湖水质及软体动物资源监测, 并通过纵向比较, 探讨了集约化养殖对大通湖水域环境及软体动物群落的影响, 以期为其渔业可持续发展提供理论依据。结果显示, 大通湖水质全年呈碱性 (8.62 0.07), 具有较高的还原性 (-88.40 9.10) mv, 属富营养水体。软体动物共计 5 科 15 种, 梨形环棱螺(Bellamya purificata)、河蚬(Corbicula fluminea)和圆顶珠蚌(Unio doug lasiae)是主要优势种。软体动物平均密度和生物量具有明显的时空差异, 时间上呈现由春夏季到秋冬季逐渐升高的趋势, 空间上整体呈现由东北向西南逐渐递减的趋势。典范对应分析表明氧化还原电位、pH、溶氧、水深、电导率和水温与大通湖软体动物时空变化的关系最显著。与 1960 年相比, 大通湖水体碱性显著增强 (7.0-7.5 vs 8.4-8.8), 电导率增加了 9 倍 (0.25-0.27 vs 2.17-2.56 mS/cm), 环境类型由氧化型转变为还原型。湖区喜好水草 (白旋螺、光亮隔扁螺、萝卜螺) 与流水生境 (德氏狭口螺、湖沼股蛤、橄榄蛏蚌) 的物种消失, 软体动物优势种群呈现由双壳类向腹足类演替的特征。生境破坏和过度捕捞是大通湖软体动物资源面临的最大威胁, 也是湖区渔业可持续发展所面临的核心问题。       

SPATIAL AND TEMPORAL VARIATION IN THE SEED BANK OF A SEMIARID GRASSLAND

The spatial and temporal variability in the seed bank of a semiarid grassland in Colorado was evaluated using soil cores. Spatial variability in the soil storage of germinable seeds was assessed by sampling two shortgrass plant communities on sites with the same climatic conditions but differing in soil texture. Differences between communities were largely the result of annual plant seeds. Eight sampling dates over two years were used to assess temporal variability, which was more important to the storage of germinable seeds than spatial variability. Differences in the numbers of seeds stored were found between the two sampling years, and seasonally within years. The number of seedlings that emerged from the samples ranged from 122–2,748/m². A poor correspondence was found between the species composition of the plant communities and the storage of germinable seeds; however, the species composition of the seeds produced on the sites tended to have a high similarity with the seedlings that emerged. Most of the species had a transient rather than a persistent presence in the seed bank.     

河北卢龙饮马河流域全新世冲积物孢粉分析及对植被时空变化 …

依据河北省卢龙县闫深港４．６ｍ厚的冲积物剖百,揭示了较高时间分辨率的孢粉分析,参照现代冲积物孢粉与植被的对应关系,探讨了距今１１０００年以来饮马河流域植被的时空变化。１１０００～９０００ａＢＰ的森林覆盖率约１０％,９０００～７０００ａＢＰ约３０％～４０％,７０００～４０００ａＢＰ约２０％～４０％,３０００～２５００ａＢＰ约１０％～２０％。在９０００ａＢＰ左右出现了云杉、冷杉花粉的高峰值,表明饮马河