The effect of temperature changes and K supply on the reproduction and growth of Bolboschoenus planiculmis

温度变化和钾添加对扁秆藨草生长及繁殖的影响 人类活动导致的气候变暖和农业面源污染已被认为是影响湿地植物生长和繁殖的重要因素。为了预 测和缓解这些人类活动的影响,研究沼泽植物如何响应这些环境变化具有重要意义。本研究选取在欧亚 大陆广泛分布的莎草科球茎植物扁秆藨草(Bolboschoenus planiculmis)为研究对象,考察气温变化(恒温： 15、20、25 °C及交替温度：20/10和30/15 °C)和钾添加(0、1、3、9 和18 mmol/L)对其生长和繁殖性状 的影响。研究结果表明,高的恒温(20、25 °C)比高的交替温度(30/15 °C)更有利于扁秆藨草球茎的形成, 而地上生物量和株高一般在较高温度下(30/15、25 °C)达到最大值。扁秆藨草的繁殖和生长性状均与施钾量 呈驼峰型关系,最适施钾量在1–3 mmol/L K。高恒温效应和最适钾浓度的交互作用对繁殖性状的促进作 用最大,但是,较高的温度(30/15和25 °C)和0–9 mmol/L的钾浓度只促进了生长性状的生长。综上所述, 扁秆藨草的种群优势度可能受益于全球变暖和额外的钾添加。     

Methane and oxygen dynamics in a shallow floodplain lake: the significance of periodic stratification

Temperature, dissolved oxygen and dissolved methane profiles were measured during autumn and summer, in a shallow floodplain lake in south-eastern Australia to determine the effects of water-column stability on methane and oxygen dynamics. The water column was well mixed in autumn. Strong thermal stratification developed in the late afternoon in summer, with top-to-bottom temperature differences of up to 6 °C. Methane concentrations in surface waters varied over a daily cycle by an 18-fold range in summer, but only by a 2-fold range in autumn. The implication of short-term temporal variation is that static chambers deployed on the water surface for short times (less than a day) in summer will significantly underestimate the diffusive component of methane emissions across the water–atmosphere interface. There was a marked diel variation in dissolved oxygen concentrations in summer, with the highest oxygen values (commonly 5–8 mg l^–1) occurring in the surface waters in late afternoon; the bottom waters were then devoid of oxygen (< 0.2 mg l^–1). Because of high respiratory demands, even the surface water layers could be nearly anoxic by morning in summer. The concentration of dissolved oxygen in the surface waters was always less than the equilibrium value. When the water column became thermally stratified in summer, the dissolved oxygen and methane maxima were spatially separated, and planktonic methanotrophy would be limited to a moving zone, at variable depth, in the water column. In summer the whole-wetland rates of oxygen production and respiration, calculated from long-term (5 h) shifts in dissolved oxygen concentrations over a diel period, were approximately 6–10 and 3–6 mmol m^–3 h^–1, respectively. These values correspond to net and gross primary production rates of 0.7–1.2 and 1.0–1.9 g C m^–3 day^–1, respectively.     

Linking seed germination and plant height: a case study of a wetland community on the eastern Tibet Plateau

• Seed germination is the earliest trait expressed in a plant's life history, and it can directly affect the expression of post‐germination traits. Plant height is central to plant ecological strategies, because it is a major determinant of the ability of a species to compete for light. Thus, linking seed germination and plant height at the community level is very important to understanding plant fitness and community structure.
• Here, we tested storage condition and temperature requirements for germination of 31 species from a wetland plant community on the eastern Tibet Plateau and analysed correlation of germination traits with plant height in relation to storage condition.
• Germination percentage was positively related to plant height, and this relationship disappeared when seeds were incubated at a low temperature (i.e. 5 °C) or after they were stored under wet‐cold conditions. The response of seeds to dry+wet–cold storage was negatively related to plant height. Based on the scores of each species on the first two principal components derived from PCA, species were classified into two categories by hierarchical clustering, and there was a significant difference between germination and plant height of species in these two categories.
• These results suggest that the requirements for seed germination together with seasonal change in environmental conditions determine the window for germination and, in turn, plant growth season and resource utilisation and ultimately plant height.

     

Redefinition of the hypotrichous ciliate Uncinata,with descriptions of the morphology and phylogeny of three urostylids (Protista,Ciliophora)

We investigated the morphology, morphogenesis and small subunit rRNA gene-based phylogeny of three marine urostylids, Uncinata gigantea Bullington, 1940 Bullington, W. E. (1940). Some ciliates from Tortugas. Papers from the Tortugas Laboratory, 32, 179–221. [Google Scholar], Holosticha heterofoissneri Hu & Song, 2001 Hu, X., & Song, W. (2001). Morphology and morphogenesis of Holosticha heterofoissneri n. sp. from the Yellow Sea, China (Ciliophora, Hypotrichida). Hydrobiologia, 448, 171–179. doi:10.1023/A:1017553406031.[Crossref], [Web of Science ®] , [Google Scholar], and Holosticha cf. heterofoissneri. The dorsal morphogenesis of Uncinata gigantea shows de novo formation of two groups of anlagen near the marginal rows. Holosticha cf. heterofoissneri demonstrates fragmentation of the first dorsal kinety anlage as in Holosticha heterofoissneri. Our population of H. heterofoissneri corresponds well with previously described populations in terms of its general morphology and ciliary pattern. Uncinata gigantea can be recognized by its large and highly contractile body, yellowish to brownish cell colour, two types of cortical granules, and 20–30 transversely oriented and densely arranged cirri in the left marginal row, which often overlie the buccal vertex. Based on the new data, especially infraciliature, the genus Uncinata is here redefined. Both the morphology and phylogenetic analyses suggest that the genus Uncinata should be classified within the family Urostylidae. In addition, both morphological and morphogenetic data suggest that Holosticha bradburyae Gong et al., 2001 Gong, J., Song, W., Hu, X., Ma, H., & Zhu, M. (2001). Morphology and infraciliature of Holosticha bradburyae n. sp. (Ciliophora, Hypotrichida) from the Yellow Sea, China. Hydrobiologia, 464, 63–69. doi:10.1023/A:1013901621439.[Crossref], [Web of Science ®] , [Google Scholar] should be transferred to Uncinata as U. bradburyae (Gong et al., 2001 Gong, J., Song, W., Hu, X., Ma, H., & Zhu, M. (2001). Morphology and infraciliature of Holosticha bradburyae n. sp. (Ciliophora, Hypotrichida) from the Yellow Sea, China. Hydrobiologia, 464, 63–69. doi:10.1023/A:1013901621439.[Crossref], [Web of Science ®] , [Google Scholar]) comb. nov., due to its possession of a characteristically prominent beak-like, leftwards curved projection and the developmental mode of the dorsal kineties. This assignment is supported by the phylogenetic analyses, which placed Uncinata gigantea in a clade with U. bradburyae (Gong et al., 2001 Gong, J., Song, W., Hu, X., Ma, H., & Zhu, M. (2001). Morphology and infraciliature of Holosticha bradburyae n. sp. (Ciliophora, Hypotrichida) from the Yellow Sea, China. Hydrobiologia, 464, 63–69. doi:10.1023/A:1013901621439.[Crossref], [Web of Science ®] , [Google Scholar]) comb. nov., and revealed only 1.13% (19 bp) difference in their SSU-rDNA gene sequence.     

克隆植物生长型的研究进展

克隆植物生长型的研究进展陈尚李自珍王刚（国家海洋局第一海洋研究所,青岛２６６００３）（兰州大学,７３００００）ＡｄｖａｎｃｅｓｉｎＲｅｓｅａｒｃｈｅｓｏｆＧｒｏｗｔｈＦｏｒｍｏｆｔｈｅＣｌｏｎａｌＰｌａｎｔ．ＣｈｅｎＳｈａｎｇ（ＦｉｒｓｔＩｎｓｔｉｔ...     

The Auchenorrhyncha fauna of peat bogs in the Austrian part of the Bohemian Forest (Insecta,Hemiptera)

The first overview on the Auchenorrhyncha fauna of peat bogs of the Austrian Bohemian Forest is presented. Seven oligotrophic peat bog sites were studied in 2011 by suction sampler (“G-Vac”) and 93 Auchenorrhyncha species (with 7465 adult specimens) were recorded. Eleven species (about 18 % of the individuals) are tyrphobiontic or tyrphophilous. The relative species abundance plot is not very steep; the six most abundant species represent 50 % of the individuals. The most common species is Conomelus anceps (17 % of the individuals). Compared to the whole Austrian Auchenorrhyncha fauna, the fauna of peat bogs comprises distinctly more univoltine species and more species hibernating in nymphal stage. Densities of adult Auchenorrhyncha in peat bogs are low in spring (about 10–60 individuals per m²) and high in July, with up to 180 (±50) individuals per m². Disturbed peat bogs have higher species numbers and higher Auchenorrhyncha densities in total, but lower numbers and densities in peat bog specialists.     

Seasonal home range dynamics and sex differences in habitat use in a threatened,coastal marsh bird

A comprehensive understanding of spatiotemporal ecology is needed to develop conservation strategies for declining species. The king rail (Rallus elegans) is a secretive marsh bird whose range historically extended across the eastern United States. Inland migratory populations have been greatly reduced with most remaining populations inhabiting the coastal margins. Our objectives were to determine the migratory status of breeding king rails on the mid‐Atlantic coast and to characterize home range size, seasonal patterns of movement, and habitat use. Using radiotelemetry, we tracked individual king rails among seasons, and established that at least a segment of this breeding population is resident. Mean (±SE) home range size was 19.8 ± 5.0 ha (95% kernel density) or 2.5 ± 0.9 (50% kernel density). We detected seasonal variation and sex differences in home range size and habitat use. In the nonbreeding season, resident male home ranges coincided essentially with their breeding territories. Overwintering males were more likely than females to be found in natural emergent marsh with a greater area of open water. Females tended to have larger home ranges than males during the nonbreeding season. We report for the first time the use of wooded natural marsh by overwintering females. Brood‐rearing king rails led their young considerable distances away from their nests (average maximum distance: ~600 ± 200 m) and used both wooded natural and impounded marsh. King rails moved between natural marsh and managed impoundments during all life stages, but the proximity of these habitat types particularly benefitted brood‐rearing parents seeking foraging areas with shallower water in proximity to cover. Our results demonstrate the importance of interspersion of habitat types to support resident breeders. Summer draining of impounded wetlands that are seasonally flooded for wintering waterfowl allows regrowth of vegetation and provides additional habitat at a critical time for wading birds.     

Enhanced denitrification in a bioaugmented horizontal subsurface flow filter

The effect of adding low concentrations of a sediment/microbial community suspension to speed up the development of the denitrification capacity in the restored HSSF of a hybrid CW was studied during a one-year period after the filling of the horizontal filter with new light weight aggregates (LWA). Two HSSF filters with the same LWA substrate but different wastewater flow regimes were used as donor systems for the bioaugmentation. NO₃-N concentrations in the outflows of all variants of studied MCs were significantly influenced by the time factor (p < 0.001, repeated measures ANOVA). Post hoc comparison indicated that MCs bioaugmented with the sediment suspension from a similar HSSF had significantly lower NO₃-N concentrations than the control MCs (p < 0.05, Fisher LSD test), whereas MCs bioaugmented with the sediment suspension from a less similar HSSF did not show significant differences compared to the control MCs. This finding emphasizes the importance of the similarity of flow regime and water parameters in choosing a donor system for bioaugmentation. High variability of the effect of bioaugmentation shows that its importance for full scale operation may be overshadowed by the effect of other factors determining denitrification intensity.     

Community Structure of Wetland Birds During Spring Migration Through the Rainwater Basin

Abstract: Staging areas and migratory stopovers of wetland birds have the potential to function as geographic bottlenecks; entire populations within a flyway may be affected by the quality and quantity of available wetland habitat at stopover sites. Although approximately 90% of playa wetlands in the Rainwater Basin (RWB) region of south-central Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for >10 million waterfowl each spring. We evaluated community patterns and species associations to assess importance of assembly rules in structuring wetland bird communities during migration and to better facilitate multispecies conservation and management strategies. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 2.6 million individual migratory wetland birds representing 72 species during 3 spring migrations 2002–2004. We evaluated spatial and temporal species co-occurrence patterns of geese, dabbling ducks, diving ducks, and shorebirds using null model analysis. Goose species co-occurrence scores did not differ from random in any year of the study, suggesting that goose species frequently use the same habitats during migration. Co-occurrence patterns among dabbling ducks were not different than expected by chance in any year; however, when we evaluated co-occurrence at a weekly scale, dabbling ducks co-occurred less often than expected during weeks of peak migration (high abundance), indicating that dabbling duck species spatially segregated at high densities. Diving duck co-occurrence patterns did not differ from random in any year, suggesting that diving duck species used the same habitats during migration. Shorebird species co-occurred less often than expected in 2002 and 2004, and during weeks of high shorebird abundance, indicating that shorebird communities were distinctly structured during those times. Most association values among lesser snow geese (Chen caerulescens) and dabbling duck species were positive, indicating dabbling ducks did not avoid wetlands with snow geese, a concern for waterfowl managers. However, we frequently observed snow geese and dabbling ducks using different microhabitats within a wetland, which indicate species associations and co-occurrence patterns may have occurred at a finer spatial scale than we measured. This approach of co-occurrence analysis will allow wildlife managers charged with multispecies management at migration stopover sites to make informed conservation and management decisions based on community structure rather than historic single-species approaches.     

Lysine Requirements of Rats of Various Body Weights

The lysine requirements of rats of various body weights were estimated using the feeding and isotope tests.

The regression equation obtained by the feeding test was Y= 1.03 – 0.58 log X. Where Y is lysine percentage of the diet and X is the mean of initial and final body weights (g) of rats achieving optimal growth gains during the feeding period.

The regression equation obtained by the isotope test was 7=0.90 – 0.49 log X, where Y and X are lysine percentage in the diet and body weights (g) of rats achieving optimal growth gains at the injection time respectively.