A framework for assessing the biodiversity and fishery aspects of marine reserves

1.  Resource management agencies are often charged with managing natural resources for economic and social goals, while also protecting and conserving biodiversity and ecosystem function. However, this may not always be possible. Ecosystem-based management is frequently suggested as a way to achieve multiple objectives in resource management and requires that trade-offs among conflicting objectives be identified and an effective means to utilize these trade-offs developed.
2.  We examine the relationship between area and species richness in a diverse assemblage of fishes along the US West Coast and then use parameters from this relationship as input for a model that considers trade-offs between fisheries yield and the number of species protected by different management strategies.
3.  The species–area relationship ( S  =  cA ^z ) for fishes along the US Pacific coast is well described by the relationship S  =   16·18 A ^0·226.
4.  There are nearly linear trade-offs between diversity and yield when fishing effort is low. However, the trade-offs become nonlinear as fishing effort increases and imposing MPAs increases both the conservation and fisheries value of the system when the system is overfished.
5.   Synthesis and applications . Solving conflicts between fisheries and conservation requires attention as to how conservation benefits accrue as fishing effort is reduced. However, scientists often lack quantitative information about the trade-offs inherent in human activities such as fisheries. The approach we develop here can begin to help frame the questions to be posed and evaluate the likely consequences of different management options.     

生物群落的种-面积关系

种—面积关系主要探讨物种数量随面积扩大而变化的规律, 它联系不同尺度的生物多样性, 是生物多样性尺度转换的重要依据。利用种—面积关系可以估算群落或区域的物种数量、评价区域生物多样性的丧失。由于构建方式、尺度效应以及区域差异, 种—面积关系的具体形式及其普适性还存在争议。本文主要从构建、尺度效应、区域分异以及与种—多度分布的联系等方面综述种—面积关系的主要进展, 并探讨它在不同方面的适用性。最后给出了利用基于组合样方系列构建的种—面积关系来估算秦岭山地物种数的实例, 结果表明估算精度良好。     

次生常绿阔叶林的群落结构与物种组成:基于浙江乌岩岭9 ha森林动态样地

常绿阔叶林是我国亚热带地区的地带性植被, 但由于长期的人为干扰, 目前仅有少量分布且主要以次生常绿阔叶林的形式存在。因此, 了解次生常绿阔叶林的物种共存机制对于保护森林生物多样性非常重要。基于大型动态监测样地对森林的物种组成及群落结构进行研究, 是揭示生物多样性维持机制的重要手段。按照美国史密森研究院热带森林科学研究中心(Center for Tropical Forest Science, CTFS)大型森林动态样地建设标准, 于2011-2012年在浙江省乌岩岭国家级自然保护区内建立了1个9 ha森林动态监测样地。通过对样地内胸径≥ 1 cm木本植物的物种组成(如重要值)、群落结构(如区系组成和径级结构等)以及空间分布的分析发现: (1)样地有木本植物存活个体47科92属200种71,396株, 其中壳斗科、樟科、山茶科、冬青科、杜鹃花科和山矾科等占优势; (2)在区系组成上, 热带成分略多于温带成分; (3)群落径级结构接近倒“J”型, 表明群落更新良好, 其中优势种径级结构呈倒“J”型、偏常态型和波动型等各种形态, 且并未表现出种群衰退的趋势; (4)优势种表现出明显的生境偏好和聚集分布格局, 暗示生境异质性可能是影响亚热带次生常绿阔叶林物种空间分布的重要因素。     

Mechanism of Photothermal Energy on the Growth and Yield of Rice under Water Level Regulation

The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage. Based on the comparative experiment and farmland water level control technology, this paper studied the average soil temperature under different soil layers (TM), the daily temperature change (TDC), the photosynthetic accumulation of single leaf and canopy in rice, and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions. The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation, and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment. Under different water gradients, the temperature decreased according to T_L > T_CK > T_H (L, H and CK represented water flooding, drought and control treatments), and the TDC was opposite. In addition to milky stage, the daily photosynthetic (Pn) accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation, and had a negative impact on leaf area index (LAI) and yield (YR), but did not form fatal damage. The root characteristic factors, RL (root length), RW (root weight), R-CR (root-canopy ratio) were promoted with drought, and YR under light drought was slightly higher than that under heavy drought. There was a strong positive correlation between TM and R-CR in all rice growth stages, while TDC-5 was negatively correlated with effective panicle number, TDC and R-CR in 20 cm soil layer were positively correlated. The correlation between daily Pn accumulation and YR was low, and the correlation between Pn and YR factors was negative or weak positive or negative. The total Pn was positively correlated with yield factors, and the correlation coefficient was higher than that of daily Pn.     

金沙江干热河谷地区植物叶片中各生源要素的化学计量特征以及异速增长关系

植物生源要素的化学计量比在生物地球化学循环以及植物生理代谢中具有极为重要的作用。迄今为止, 对植物叶片的N、P元素与其他生源要素含量间相关关系的研究较少, 限制了生态化学计量学的应用广度。为了解金沙江干热河谷地区植物叶片中各种生源要素间的异速增长关系, 该研究通过对当地51个样方中107个样本的测量, 探索个体水平、物种水平和样方水平上各生源要素间的异速增长关系。结果显示: 叶片中各元素的比例N:P:K:S:Fe:Ca为100.00:6.64:88.20:11.59:2.48:91.64, N、P含量分别为11.21和0.744 mg·g ^-1, 明显低于全国平均值, 而N:P与全国平均值相当, 表明植物生长受到N、P的双重限制。各种生源要素间存在正相关增长关系, 在个体水平上, 植物叶片中N-P大致呈等速增长关系, Fe与Ca元素相对于N、P、K的增长速率显著大于1, Fe的增长速率最大, 依次为Fe > Ca > P > N > S > K; 物种水平上Fe与Ca相对于N、P、K的增长速率显著大于1; 样方水平上, Fe元素相对于N、P、K的增长速率依旧显著大于1, 但Ca、S相对于N的增长速率显著大于1, 元素增长速率为Fe > Ca > P > S > K > N, 其中N相对于P的异速增长斜率与2/3极为接近, K相对于P的异速增长斜率接近3/4。个体水平和样方水平上各种元素间的相关关系以及拟合优度不一致, 表明群落构建在介导不同层次上元素关系中发挥着重要作用。     

Studies on structure activity relationship of some dihydroxy-4-methylcoumarin antioxidants based on their interaction with Fe(III) and ADP

Three dihydroxy-4-methylcoumarin (DHMC) derivatives, namely 7,8-DHMC, 6,7-DHMC and 5,7-DHMC alone and complexed with Fe (III) and ADP have been tested for their antioxidative potential. Chemical speciation studies and formation constants reveal the formation of strong DHMC–Fe–ADP (1:1:1) ternary complex. In vitro studies were done for their antioxidative property by scavenging the superoxide radicals (O ₂ ^– ) generated by xanthine + xanthine oxidase (XO) reaction. The IC₅₀ values for 7,8-DHMC, 6,7-DHMC and 5,7-DHMC and their ternary complexes with Fe (III)–ADP worked out to be 34.0 M, 62.0 M, 8.80 mM and 10.5, 11.5 and 148.5 M, respectively. The results indicate that O ₂ ^– scavenging potential of all the three DHMCs increased significantly after forming the ternary complex with Fe(III) and ADP. The structure activity relationship studies suggest that the introduction of hydroxyl group at 7th and 8th positions in the coumarins, irrespective of Fe(III)–ADP complexation, increases the antioxidative efficacy. No change in uric acid production in the reactions done for all studies further reveals that the coumarin derivatives and their complexes were the only causative factors for O ₂ ^– scavenging and not the suppression of the enzyme, xanthine oxidase.Published online: March 2005     

Genetic diversity patterns in Phragmites australis at the population,regional and continental scales

Genetic diversity, population structure and interrelationships were investigated in eight populations of the common reed, Phragmites australis, in the Po Plain, Italy, by means of amplified fragments length polymorphisms (AFLPs) and random amplified polymorphic DNAs (RAPDs). Patterns of genetic diversity were analysed in relation to size, age and degree of human impact in the wetlands and compared with that of a distant population in Romania. Genetic distances between Po Plain clones and geographically distant clones were measured to determine the geographical extent of the gene pool.     

An evolutionary and structure-based docking model for glucocerebrosidase-saposin C and glucocerebrosidase-substrate interactions - relevance for Gaucher disease

Gaucher disease, the most prevalent lysosomal storage disorder, is principally caused by malfunction of the lysosomal enzyme glucocerebrosidase (GBA), a 497-amino acid membrane glycoprotein that catalyzes the hydrolysis of glucosylceramide to ceramide and glucose in the presence of an essential 84-residue activator peptide named saposin C (SapC). Knowledge of the GBA structure, a typical (beta/alpha)(8) TIM barrel, explains the effect of few mutations, directly affecting or located near the catalytic site. To identify new regions crucial for proper GBA functionality, we analyzed the interactions of the enzyme with a second (substrate) and a third (cofactor) partner. We build 3D docking models of the GBA-SapC and the GBA-ceramide interactions, by means of methodologies that integrate both evolutive and structural information. The GBA-SapC docking model confirm the implication of three spatially closed regions of the GBA surface (TIM barrel-helix 6 and helix 7, and the Ig-like domain) in binding the SapC molecule. This model provides new basis to understand the pathogenicity of several mutations, such as the prevalent Leu444Pro, and the additive effect of Glu326Lys in the double mutant Glu326Lys-Leu444Pro. Overall, 39 positions in which amino acid changes are known to cause Gaucher disease were localized in the GBA regions identified in this work. Our model is discussed in relation to the phenotype (pathogenic effect) of these mutations, as well as to the enzymatic activity of the recombinant proteins when available. Both data fully correlates with the proposed model, which will provide a new tool to better understand Gaucher disease and to design new therapy strategies.     

Causality between abundance and diversity is weak for wintering migratory waterbirds

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