Consequences of early chilling stress in two Triticum species: plastic responses and adaptive significance

Phenotypic plasticity of two primitive wheat species (Triticum monococcum L. and Triticum dicoccum S.) was studied in response to early chilling stress. Selection pressure differentials, gradients and plasticity costs on plant morphogenesis, growth and reserve carbohydrate consumption were estimated. Regression analysis was applied to investigate differential developmental changes and patterns between treatments. Four‐day‐old seedlings of T. monococcum and T. dicoccum, differing in plant stature and reserve carbohydrates, were given an early chilling temperature (4 °C for 42 day) and compared with control plants grown at 23 °C. Early chilling stress resulted in a significant increase in leaf mass ratio (LMR) and relative growth rate (RGR), a reduction in flag leaf size, total biomass, specific leaf area (SLA) and reserve carbohydrate storage at flowering, together with advanced onset of flowering. Selection pressure within the early chilling environment favoured early flowering, smaller SLA, higher LMR and lower reserve carbohydrates, suggesting the observed responses were adaptive. Furthermore, a regression of daily cumulative plant biomass derived from a crop growth simulation model (CERES‐Wheat) on crop vegetation period revealed a divergent developmental pattern in early‐chilled plants. Using selection pressure gradient analysis, we found similar responses among these traits, except for SLA and sucrose, indicating that these two traits have indirect effects on fitness. Thus, the total effects of SLA and reserve sucrose on relative fitness seem to be buffered via the rapid growth rate in chilled plants. While lower SLA may reduce early chilling stress effects at an individual leaf level, a higher LMR and use of reserve carbohydrates indicated that compensatory growth of chilled plants during the recovery period relied on the concerted action of altered resource allocation and reserve carbohydrate consumption. However, a significant cost of plasticity was evident only for flowering time, LMR and fructan levels in the early chilling environment. Our results demonstrate that morphological and intrinsic developmental (ontogenetic) patterns in two Triticum species respond to early chilling stress.     

Maximising return on conservation investment in the conterminous USA

Efficient conservation planning requires knowledge about conservation targets, threats to those targets, costs of conservation and the marginal return to additional conservation efforts. Systematic conservation planning typically only takes a small piece of this complex puzzle into account. Here, we use a return‐on‐investment (ROI) approach to prioritise lands for conservation at the county level in the conterminous USA. Our approach accounts for species richness, county area, the proportion of species' ranges already protected, the threat of land conversion and land costs. Areas selected by a complementarity‐based greedy heuristic using our full ROI approach provided greater averted species losses per dollar spent compared with areas selected by heuristics accounting for richness alone or richness and cost, and avoided acquiring lands not threatened with conversion. In contrast to traditional prioritisation approaches, our results highlight conservation bargains, opportunities to avert the threat of development and places where conservation efforts are currently lacking.     

广东莲花山白盆珠省级自然保护区鸟类资源调查

于2008年1月～2010年12月对广东莲花山白盆珠省级自然保护区鸟类进行了调查,共记录到鸟类151种,隶属于45科16目。其中非雀形目鸟类74种(占49.01%),雀形目77种(50.99%);94种属东洋界种类(62.25%),42种属古北界种类(27.81%),15种属广布种(9.93%);留鸟88种(58.28%)、冬候鸟44种(29.14%)、夏候鸟15种(9.93%)、旅鸟和迷鸟4种(2.65%);国家Ⅱ级重点保护鸟类22种(14.57%)。该保护区鸟类特色是中华秋沙鸭种群数量较大,猛禽资源和水鸟资源较丰富。     

Differences of ecological functions inside and outside the wetland nature reserves in Sanjiang Plain, China

Conservation effectiveness of wetland nature reserves is determined by both the management intensity inside the reserves and the hydrological status outside the reserves. Therefore, differences of ecological functions inside and outside the reserves are an integrated indictor for assessing conservation effectiveness. Based on the land use map created from Landsat-TM satellite image and 1:50000 Digital Elevation Model (DEM) data in the study area, the catchments that belong to the wetland reserves were determined as their hydrological sensitive zones by SWAT (Soil and Water Assessment Tool) hydrological model. The ecological function indices of wetland reserves and their corresponding hydrological sensitive zones were calculated through expert consultation and value assessment on wetland ecosystem service functions. The results showed that the ecological functions of national wetland reserves were better than those of local reserves in general. However, the wetland ecological functions of hydrological sensitive zones of the former were not always better than those of the latter. Meanwhile, clustering analysis showed that the wetland ecological functions of several adjacent reserves in Nongjiang-Bielahonghe watershed were similar. But correlation analysis found that there existed a remarkable positive correlation between the wetland ecological function indices of local reserves and their hydrological sensitive zones.     

江西齐云山自然保护区两栖爬行动物资源调查与区系分析

为掌握江西齐云山自然保护区野生动物资源现状,促进自然保护区的有效管理和建设,作者于2007年1月10～19日、5月16～24日、7月26日～8月8日,前后3次对该保护区两柄爬行动物资源进行了实地考察.调查结果显示,齐云山保护区现已记录72种两栖爬行动物,隶属5目18科.其中两栖纲2目7科24种,爬行纲3目11科48种.齐云山保护区动物地理区划属东洋界华中区东部丘陵平原亚区,其区系组成以60种东洋界种类占明显优势,其余12种均为广布种,无古北界物种分布.大眼斜鳞蛇福建亚种(Pseudoxenodon macrops fukienensis)和寒露林蛙(Rana hanluica)为江西省两栖爬行动物新纪录,福建钝头蛇(Pareas stanleyi)为江西省赣南地区爬行动物新纪录.齐云山保护区是海南棱蜥後(Tropidophorus hainanus)和福建华珊瑚蛇(福建丽纹蛇)(Sinomicrurus kettoggi)在江西省的第二个发现地,是海南闪鳞蛇(Xenopeltis hainanensis)在江西省的第三个采集地.通过平均动物区系相似性分析发现,齐云山地理位置独特,是华中区和华南区物种重要的扩散过渡地域.最后对齐云山保护区的保护与管理工作提出了建议.     

陕西米仓山自然保护区夏秋季鸟类调查

2006年7~10月,对陕西米仓山自然保护区的鸟类资源进行了调查研究。结果显示,保护区鸟类13目37科81属125种(亚种),鸟类种数分别占秦岭鸟类总种数的36·98%及陕西省鸟类总种数的33·42%。其中国家Ⅰ级重点保护野生动物1种,国家Ⅱ级重点保护野生动物12种,陕西省省级重点保护野生动物4种;我国特有鸟类13种;CITES附录Ⅱ鸟类10种。按区系成分划分,东洋种57种,古北种37种,广布种27种。按居留型划分,留鸟89种,夏候鸟32种,冬候鸟2种,旅鸟2种。与陕西佛坪、重庆大巴山等周边保护区相比,米仓山保护区的鸟类多样性比较丰富,区系成分以东洋种为主,并具有东洋界和古北界过渡区的特征。     

Light-induced degradation of storage starch in turions of Spirodela polyrhiza depends on nitrate

Light induces both the germination of turions of the duckweed Spirodela polyrhiza and the degradation of the reserve starch stored in the turions. The germination photoresponse requires nitrate, and we show here that nitrate is also needed for the light-induced degradation of the turion starch. Ammonium cannot substitute for nitrate in this regard, and nitrate thus acts specifically as signal to promote starch degradation in the turions. Irradiation with continuous red light leads to starch degradation via auto-phosphorylation of starch-associated glucan, water dikinase (GWD), phosphorylation of the turion starch and enhanced binding of alpha-amylase to starch granules. The present study shows that all of these processes require the presence of nitrate, and that nitrate exerts its effect on starch degradation at a point between the absorption of light by phytochrome and the auto-phosphorylation of the GWD. Nitrate acts to coordinate carbon and nitrogen metabolism in germinating turions: starch will only be broken down when sufficient nitrogen is present to ensure appropriate utilization of the released carbohydrate. These data constitute the first report of control over the initiation of reserve starch degradation by nitrate.     

A Review of Catch-and-Release Angling Mortality with Implications for No-take Reserves

Management agencies have increasingly relied on size limits, daily bag or trip limits, quotas, and seasonal closures to manage fishing in recreational and commercial fisheries. Another trend is to establish aquatic protected areas, including no-take reserves (NTRs), to promote sustainable fisheries and protect aquatic ecosystems. Some anglers, assuming that no serious harm befalls the fish, advocate allowing catch-and-release (C&R) angling in aquatic protected areas. The ultimate success of these regulations and C&R angling depends on ensuring high release survival rates by minimizing injury and mortality. To evaluate the potential effectiveness of these practices, we review trends in C&R fishing and factors that influence release mortality. Analysis of Marine Recreational Fishery Statistic Survey (MRFSS) data for 1981–1999 showed no statistically significant U.S. trends for total number of anglers (mean 7.7 × 10⁶), total catch in numbers (mean 362 × 10⁶), or total annual catch/angler (mean 42.6 fish). However, mean total annual landings declined 28% (188.5 to 135.7 × 10⁶), mean total catch/angler/trip declined 22.1% (0.95 to 0.74 fish), and mean landings/angler/trip declined 27% (0.42 to 0.31 fish). The total number of recreational releases or discards increased 97.1% (98.0 to 193.2 × 10⁶) and as a proportion of total catch from 34.2% in 1981 to 58.0% in 1999. Evidence indicates that the increased releases and discards are primarily in response to mandatory regulations and to a lesser extent, voluntary releases. Total annual catch and mean annual catch/angler were maintained despite declines in catch per trip because anglers took 30.8% more fishing trips (43.5 to 56.9 × 10⁶), perhaps to compensate for greater use of bag and size limits. We reviewed 53 release mortality studies, doubling the number of estimates since Muoneke and Childress (1994) reviewed catch and release fishing. A meta-analysis of combined data (n=274) showed a skewed distribution of release mortality (median 11%, mean 18%, range 0–95%). Mortality distributions were similar for salmonids, marine, and freshwater species. Mean mortality varied greatly by species and within species, anatomical hooking location was the most important mortality factor. Other significant mortality factors were: use of natural bait, removing hooks from deeply hooked fish, use of J-hooks (vs. circle hooks), deeper depth of capture, warm water temperatures, and extended playing and handling times. Barbed hooks had marginally higher mortality than barbless hooks. Based on numbers of estimates, no statistically significant overall effects were found for fish size, hook size, venting to deflate fish caught at depth, or use of treble vs. single hooks. Catch and release fishing is a growing and an increasingly important activity. The common occurrence of release mortality, however, requires careful evaluation for achieving fishery management goals and in some cases, disturbance, injury, or mortality may conflict with some goals of NTRs. Research is needed to develop better technology and techniques to reduce release mortality, to assess mortality from predation during capture and after release, to determine cumulative mortality from multiple hooking and release events, and to measure sub-lethal effects on behavior, physical condition, growth, and reproduction.     

Forest Restoration in Urbanizing Landscapes: Interactions Between Land Uses and Exotic Shrubs

Preventing and controlling exotic plants remains a key challenge in any ecological restoration, and most efforts are currently aimed at local scales. We combined local‐ and landscape‐scale approaches to identify factors that were most closely associated with invasion of riparian forests by exotic shrubs (Amur honeysuckle [Lonicera maackii] and Tatarian honeysuckle [L. tatarica]) in Ohio, U.S.A. Twenty sites were selected in mature riparian forests along a rural–urban gradient (<1–47% urban land cover). Within each site, we measured percent cover of Lonicera spp. and native trees and shrubs, percent canopy cover, and facing edge aspect. We then developed 10 a priori models based on local‐ and landscape‐level variables that we hypothesized would influence percent cover of Lonicera spp. within 25 m of the forest edge. To determine which of these models best fit the data, we used an information‐theoretic approach and Akaike's information criterion. Percent cover of Lonicera was best explained by the proportion of urban land cover within 1 km of riparian forests. In particular, percent cover of Lonicera was greater in forests within more urban landscapes than in forests within rural landscapes. Results suggest that surrounding land uses influence invasion by exotic shrubs, and explicit consideration of land uses may improve our ability to predict or limit invasion. Moreover, identifying land uses that increase the risk of invasion may inform restoration efforts.     

Place prioritization for biodiversity conservation using probabilistic surrogate distribution data

We analyse optimal and heuristic place prioritization algorithms for biodiversity conservation area network design which can use probabilistic data on the distribution of surrogates for biodiversity. We show how an Expected Surrogate Set Covering Problem (ESSCP) and a Maximal Expected Surrogate Covering Problem (MESCP) can be linearized for computationally efficient solution. For the ESSCP, we study the performance of two optimization software packages (XPRESS and CPLEX) and five heuristic algorithms based on traditional measures of complementarity and rarity as well as the Shannon and Simpson indices of α‐diversity which are being used in this context for the first time. On small artificial data sets the optimal place prioritization algorithms often produced more economical solutions than the heuristic algorithms, though not always ones guaranteed to be optimal. However, with large data sets, the optimal algorithms often required long computation times and produced no better results than heuristic ones. Thus there is generally little reason to prefer optimal to heuristic algorithms with probabilistic data sets.