Quantifying the impact of vegetation-based metrics on species persistence when choosing offsets for habitat destruction

Developers are often required by law to offset environmental impacts through targeted conservation actions. Most offset policies specify metrics for calculating offset requirements, usually by assessing vegetation condition. Despite widespread use, there is little evidence to support the effectiveness of vegetation-based metrics for ensuring biodiversity persistence. We compared long-term impacts of biodiversity offsetting based on area only; vegetation condition only; area × habitat suitability; and condition × habitat suitability in development and restoration simulations for the Hunter Region of New South Wales, Australia. We simulated development and subsequent offsetting through restoration within a virtual landscape, linking simulations to population viability models for 3 species. Habitat gains did not ensure species persistence. No net loss was achieved when performance of offsetting was assessed in terms of amount of habitat restored, but not when outcomes were assessed in terms of persistence. Maintenance of persistence occurred more often when impacts were avoided, giving further support to better enforce the avoidance stage of the mitigation hierarchy. When development affected areas of high habitat quality for species, persistence could not be guaranteed. Therefore, species must be more explicitly accounted for in offsets, rather than just vegetation or habitat alone. Declines due to a failure to account directly for species population dynamics and connectivity overshadowed the benefits delivered by producing large areas of high-quality habitat. Our modeling framework showed that the benefits delivered by offsets are species specific and that simple vegetation-based metrics can give misguided impressions on how well biodiversity offsets achieve no net loss.     

Effectiveness of biodiversity-conservation marketing

Conservation marketing holds potential as a means to engage audiences with biodiversity conservation and help to address the human dimensions of biodiversity loss. Empirical evaluations of conservation marketing indicatives are growing, so we reviewed the literature on this research to inform future directions in the field. We used a systematic search strategy to identify studies that evaluated the effects of conservation marketing interventions (techniques and campaigns) on psychosocial outcomes, categorized as cognitive, affective, or behavioral. Six academic databases (Business Source Complete, Communication & Mass Media Complete, Greenfile, Proquest, Scopus, and Web of Science Core Collections), 3 gray-literature databases (BASE, Zenodo, and Google Scholar), and 2 websites (Rare and WildAid) were searched. Articles were subjected to critical appraisal to assess their methodological quality, and data were extracted from each article and analyzed using narrative synthesis. Altogether 28 studies from 26 articles were included in the review. Twenty-five studies were conducted from 2014 through 2016. Methodological quality of most studies was weak (n = 16, 57%) (moderate quality n = 8, 29%; high quality n = 4, 14%). The proportion of studies that evaluated a conservation-marketing technique (e.g., variants of texts, images, or videos) versus a campaign (e.g., community-based campaigns targeting locally relevant issues, such as unsustainable palm oil agriculture, light pollution, or wood fuel fire use) was relatively balanced. Although many studies reported statistically significant results in the intended direction, the utility of findings was limited by persistent methodological limitations, such as a lack of a comparator group, use of non-validated assessment tools, and a focus on self-reported data and subjective outcomes. Conservation marketing is clearly a nascent field of scientific enquiry that warrants further, high-quality research investigations.     

The moral residue of conservation

Should conservationists use lethal management to control introduced wildlife populations? Should they kill individual animals to protect endangered species? Are trade-offs that prioritize some values at the expense of others morally appropriate? These sorts of ethical questions are common in conservation. In debating such questions, conservationists often seem to presume 1 of 2 possible answers: the act in question is right or it is wrong. But morality in conservation is considerably more complex than this simple binary suggests. A robust conservation ethic requires a vocabulary that gives voice to the uncertainty and unease that arise when what seems to be the best available course of action also seems to involve a measure of wrongdoing. The philosophical literature on moral residue and moral dilemmas supplies this vocabulary. Moral dilemmas arise when one must neglect certain moral requirements to fulfill others. Under such circumstances, even the best possible decision leaves a moral residue, which is experienced emotionally as some form of grief. Examples of conservation scenarios that leave a moral residue include management of introduced rabbits in Australia, trophy hunting in Africa, and forest management trade-offs in the Pacific Northwest. Moral residue is integral to the moral experience of conservationists today, and grief is an appropriate response to many decisions conservationists must make. Article impact statement: Defensible conservation decisions may neglect moral requirements, leaving a moral residue; conservationists should respond with grief.     

Applying the zoo model to conservation of threatened exceptional plant species

Maintaining a living plant collection is the most common method of ex situ conservation for plant species that cannot be seed banked (i.e., exceptional species). Viability of living collections, and their value for future conservation efforts, can be limited without coordinated efforts to track and manage individuals across institutions. Using a pedigree-focused approach, the zoological community has established an inter-institutional infrastructure to support long-term viability of captive animal populations. We assessed the ability of this coordinated metacollection infrastructure to support the conservation of 4 plant species curated in living collections at multiple botanic gardens around the world. Limitations in current practices include the inability to compile, share, and analyze plant collections data at the individual level, as well as difficulty in tracking original provenance of ex situ material. The coordinated metacollection framework used by zoos can be adopted by the botanical community to improve conservation outcomes by minimizing the loss of genetic diversity in collections. We suggest actions to improve ex situ conservation of exceptional plant species, including developing a central database to aggregate data and track unique individuals of priority threatened species among institutions and adapting a pedigree-based population management tool that incorporates life-history aspects unique to plants. If approached collaboratively across regional, national, and global scales, these actions could transform ex situ conservation of threatened plant species.     

Validating graph-based connectivity models with independent presence–absence and genetic data sets

Habitat connectivity is a key objective of current conservation policies and is commonly modeled by landscape graphs (i.e., sets of habitat patches [nodes] connected by potential dispersal paths [links]). These graphs are often built based on expert opinion or species distribution models (SDMs) and therefore lack empirical validation from data more closely reflecting functional connectivity. Accordingly, we tested whether landscape graphs reflect how habitat connectivity influences gene flow, which is one of the main ecoevolutionary processes. To that purpose, we modeled the habitat network of a forest bird (plumbeous warbler [Setophaga plumbea]) on Guadeloupe with graphs based on expert opinion, Jacobs’ specialization indices, and an SDM. We used genetic data (712 birds from 27 populations) to compute local genetic indices and pairwise genetic distances. Finally, we assessed the relationships between genetic distances or indices and cost distances or connectivity metrics with maximum-likelihood population-effects distance models and Spearman correlations between metrics. Overall, the landscape graphs reliably reflected the influence of connectivity on population genetic structure; validation R² was up to 0.30 and correlation coefficients were up to 0.71. Yet, the relationship among graph ecological relevance, data requirements, and construction and analysis methods was not straightforward because the graph based on the most complex construction method (species distribution modeling) sometimes had less ecological relevance than the others. Cross-validation methods and sensitivity analyzes allowed us to make the advantages and limitations of each construction method spatially explicit. We confirmed the relevance of landscape graphs for conservation modeling but recommend a case-specific consideration of the cost-effectiveness of their construction methods. We hope the replication of independent validation approaches across species and landscapes will strengthen the ecological relevance of connectivity models.     

陈家大院泡湖泊湿地植物多样性研究

研究陈家大院泡湖泊湿地植物多样性规律对于改善大庆市萨尔图区的生态环境,了解物种群落丰富度具有重要意义.通过野外样地调查,分析了陈家大院泡湖泊湿地植物群落组成,并计算了植物群落多样性特征指数,包括Margalef指数,Simpson指数,Shannon-wiener指数和Pielou均匀度指数,结果表明,研究区湖泊湿地共有38种植物,分别隶属于18科34属,除榆树为木本植物外,有36种草本植物以及1种藓类植物.经数据处理后得出,每个样方平均含有3个物种,植株个体数目平均为115,Margalef指数平均值为0.567,Simpson指数平均值为0.814,Shannon-wiener指数平均值为0.313,Pielou均匀度指数平均值为0.267.由此看出,陈家大院泡湖泊湿地植物多样性水平较低,植物群落组成较为单一,生态环境脆弱.     

鄱阳湖典型湿地沉水植物的分布格局及其水环境影响因子

沉水植物是湖泊湿地生态系统中关键组分,调查研究沉水植物分布格局及其水环境影响因子,对于沉水植被的恢复与重建具有重要的指导意义。2013年5月初期分别对鄱阳湖典型湿地区域中有沉水植物的25个样地进行群落结构调查,采用系统取样方法对沉水植物进行调查采样并监测水环境因子,在野外调查的基础上运用GIS软件制作鄱阳湖典型区域沉水植物的生物量分布图,并采用主成分分析(PCA)和典范对应分析(CCA)方法分析其主要影响因子。结果表明:鄱阳湖湿地沉水植物以苦草(Vallisneria natans)为广布种,其中蚌湖及白沙湖以黑藻(Hydrilla verticillata)为优势种,白沙洲及乐安河龙口段以苦草为优势种,伴生种主要有金鱼藻(Ceratophyllum demersum)、马来眼子菜(Potamogeton malaianus)、菹草(P.crispus)、小茨藻(Najas minor)、大茨藻(N.marina)、刺苦草(V.spinulosa)和水车前(Ottelia alismoides)等。采用双向指示种分析法将研究区沉水植物分为6个群落;5月初大部分沉水植物尚处于生长季初期,生物量相对较低,仅菹草的生物量较大;沉水植物与浮叶植物共存现象明显。主成分分析(PCA)结果显示,第一主成分中水深、总磷和溶解氧等因子的系数值较大,第二主成分中pH值、化学需氧量和水体透明度等因子的系数值较大,是影响沉水植物分布的关键因子;典范对应分析(CCA)结果显示,水深、总磷和总氮对苦草和黑藻的影响显著,水体透明度是马来眼子菜的主要影响因子。     

河口盐沼植物分布对有效光合辐射的响应

对东滩植被带光量子通量密度的调查研究表明:互花米草带与海三棱藨草带光量子通量密度没有显著性差异,其值分别为1 570和1 556μmol/(m2·s)。光照对两物种的生长、繁殖等植物行为的影响只取决于其对光照的利用能力和效率;在互花米草和海三棱藨草混生带,到达互花米草和海三棱藨草的光量子通量密度之间存在显著差异(P0.05),互花米草对海三棱藨草的遮荫效应达63%,表明互花米草对海三棱藨草具有强的遮荫作用。光照不足严重影响海三棱藨草的生长,在混生带,海三棱藨草生长速率降低,种群密度和生物量减少,植株高度增加。因此,互花米草对海三棱藨草的遮荫作用,抑制了海三棱藨草在中潮滩的更新过程,因而也是造成海三棱藨草生境丧失的重要原因之一。     

胞外聚合物磷酸盐形态对生物除磷过程的影响研究

以不同DO条件下污泥龄(SRT)分别为10 d和30 d的两组实验室A/O-SBR反应器活性污泥为研究对象,探讨了胞外聚合物(EPS)磷酸盐形态对生物除磷过程的影响.结果表明,污泥絮体中的磷主要分布于EPS中,PO3-4-P和聚磷酸盐(Poly-P,包括低分子量聚磷酸盐LMW PolyP和高分子量聚磷酸盐HMW Poly-P)是EPS磷的主要形态;EPS对生物除磷的影响明显大于细菌细胞,EPS磷的厌氧降低量和好氧升高量为胞内磷变化量的2.8~6.4倍.EPS中的LMW Poly-P和HMW Poly-P含量均表现厌氧降低和好氧升高的变化规律;对于相同SRT的污泥,中DO(2.5~3.5 mg·L-1)条件较低DO(0.7~1.0 mg·L-1)条件下EPS的LMW Poly-P和HMW Poly-P有更大的厌氧降低量和好氧升高量,对应着更明显的生物除磷过程,说明EPS不仅是生物除磷过程的中转站,而且参与了生物聚磷过程.