Pyric Herbivory: Rewilding Landscapes through the Recoupling of Fire and Grazing

Abstract:  Our understanding of fire and grazing is largely based on small-scale experimental studies in which treatments are uniformly applied to experimental units that are considered homogenous. Any discussion of an interaction between fire and grazing is usually based on a statistical approach that ignores the spatial and temporal interactions on complex landscapes. We propose a new focus on the ecological interaction of fire and grazing in which each disturbance is spatially and temporally dependent on the other and results in a landscape where disturbance is best described as a shifting mosaic (a landscape with patches that vary with time since disturbance) that is critical to ecological structure and function of many ecosystems. We call this spatiotemporal interaction pyric herbivory (literal interpretation means grazing driven by fire). Pyric herbivory is the spatial and temporal interaction of fire and grazing, where positive and negative feedbacks promote a shifting pattern of disturbance across the landscape. We present data we collected from the Tallgrass Prairie Preserve in the southern Great Plains of North America that demonstrates that the interaction between free-roaming bison ( Bison bison ) and random fires promotes heterogeneity and provides the foundation for biological diversity and ecosystem function of North American and African grasslands. This study is different from other studies of fire and grazing because the fires we examined were random and grazing animals were free to roam and select from burned and unburned patches. For ecosystems across the globe with a long history of fire and grazing, pyric herbivory with any grazing herbivore is likely more effective at restoring evolutionary disturbance patterns than a focus on restoring any large vertebrate while ignoring the interaction with fire and other disturbances .     

Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes

Abstract:  Managed landscapes in which non-native ornamental plants are favored over native vegetation now dominate the United States, particularly east of the Mississippi River. We measured how landscaping with native plants affects the avian and lepidopteran communities on 6 pairs of suburban properties in southeastern Pennsylvania. One property in each pair was landscaped entirely with native plants and the other exhibited a more conventional suburban mixture of plants—a native canopy with non-native groundcover and shrubs. Vegetation sampling confirmed that total plant cover and plant diversity did not differ between treatments, but non-native plant cover was greater on the conventional sites and native plant cover was greater on the native sites. Several avian (abundance, species richness, biomass, and breeding-bird abundance) and larval lepidopteran (abundance and species richness) community parameters were measured from June 2006 to August 2006. Native properties supported significantly more caterpillars and caterpillar species and significantly greater bird abundance, diversity, species richness, biomass, and breeding pairs of native species. Of particular importance is that bird species of regional conservation concern were 8 times more abundant and significantly more diverse on native properties. In our study area, native landscaping positively influenced the avian and lepidopteran carrying capacity of suburbia and provided a mechanism for reducing biodiversity losses in human-dominated landscapes.     

辽河浮游植物群落及生物多样性基准验证

为建立中国水环境生态学基准体系,并验证其合理性,于2011和2012年夏季,对辽河水系浮游植物群落结构特征进行了调查,并结合所收集到的资料,初步验证了辽河水系浮游植物生物多样性基准值的合理性.两次采样共检出6门169种及变种;细胞密度均值分别为4.91×106,7.04×106个/L,优势类群为硅藻和绿藻.共检出污染指示种59种,其中乙型中污指示种最多,为53种;检出优势种35种,主要为硅藻.综合各生物指标显示辽河水系夏季为富营养型中度污染水体.Shannon指数(H)在1.18~3.56之间,均未达到本文参考的基准值3.65,分析结果显示用于计算基准值所选取的参照点较为合适,通过分析辽河水系及我国其他一些河流的Shannon指数与水质状况,初步认为,该基准值偏高,建议辽河水系设定基准值的下限H=3.29.     

Importance of Baseline Specification in Evaluating Conservation Interventions and Achieving No Net Loss of Biodiversity

There is an urgent need to improve the evaluation of conservation interventions. This requires specifying an objective and a frame of reference from which to measure performance. Reference frames can be baselines (i.e., known biodiversity at a fixed point in history) or counterfactuals (i.e., a scenario that would have occurred without the intervention). Biodiversity offsets are interventions with the objective of no net loss of biodiversity (NNL). We used biodiversity offsets to analyze the effects of the choice of reference frame on whether interventions met stated objectives. We developed 2 models to investigate the implications of setting different frames of reference in regions subject to various biodiversity trends and anthropogenic impacts. First, a general analytic model evaluated offsets against a range of baseline and counterfactual specifications. Second, a simulation model then replicated these results with a complex real world case study: native grassland offsets in Melbourne, Australia. Both models showed that achieving NNL depended upon the interaction between reference frame and background biodiversity trends. With a baseline, offsets were less likely to achieve NNL where biodiversity was decreasing than where biodiversity was stable or increasing. With a no‐development counterfactual, however, NNL was achievable only where biodiversity was declining. Otherwise, preventing development was better for biodiversity. Uncertainty about compliance was a stronger determinant of success than uncertainty in underlying biodiversity trends. When only development and offset locations were considered, offsets sometimes resulted in NNL, but not across an entire region. Choice of reference frame determined feasibility and effort required to attain objectives when designing and evaluating biodiversity offset schemes. We argue the choice is thus of fundamental importance for conservation policy. Our results shed light on situations in which biodiversity offsets may be an inappropriate policy instrument Importancia de la Especificación de Línea de Base en la Evaluación de Intervenciones de Conservación y la Obtención de Ninguna Pérdida Neta de la Biodiversidad     

Reducing emissions from deforestation and forest degradation (REDD) projects: lessons for future policy design and implementation

In response to the pressing global challenges of climate change, initiatives under the auspices of ‘reducing emissions from deforestation and forest degradation’ (REDD) have been implemented in over 30 developing and least-developed countries since 2005. The initiatives cover nearly every significant and vulnerable forest ecosystem worldwide. In this study we review six representative initiatives, two each from Africa, Asia and Latin America. Strength, weakness, opportunity and threat analysis is done to evaluate each initiative's policy framework, design, implementation and results thus far. The main policy and project implementation factors that appear to lead to effective and successful REDD project outcomes include having clearly formulated project design; governance, land tenure rights and capacity; equity and transparency; indigenous peoples' rights and knowledge; local–international coordination; and enhancing local and institutional capacities. Based on these findings, we provide recommendations for future REDD policy action and project implementation to make it work for the poor and achieve its intended goals.     

基于主体建模的废物交换模型与仿真分析

作为产业共生中一种重要的关系,废物交换不仅能解决废物处置的难题,还可以降低原料供给的成本与风险. 企业进行废物交换的动力主要来源于经济利益的驱动. 从交换的市场机制出发,运用基于主体建模的方法构建了废物交换的模型框架,并且基于Swarm平台进行了仿真分析. 结果表明:系统的废物交换价格指数在仿真开始后10个周期内迅速降至4左右,并在之后的周期内缓慢下降;系统中单个废物的价格波动较大,但这种波动并未反映到整体的价格指数中;系统中的废物交换量和参与交换的企业数量均呈上升的趋势,但废物交换量的增长呈先慢后快的态势,在第200个周期时达到25×104 t. 而参与交换企业数量的增长呈先快后慢态势并逐渐稳定在100家左右. 示范企业的选取对于系统的废物交换量有一定的影响,选取规模较大的企业作为示范企业比随机选取更能促进系统中的废物交换,在第200个周期时比随机选择下的交换量高出约50%.      

江河源区主要自然生物资源概述

广袤的草地、特有的高寒湿地以及丰富而有又独特的生物多样性是江河源区重要的自然生物资源。草地占江河源区总土地面积的84.53%,是源区畜牧业经济发展的基础,同时也是长江、黄河和澜沧江三大江河的源头区域,为江河中、下游地区生态环境稳定和经济持续发展提供无可替代的服务。江河源区是世界上海拔最高的高寒湿地主要分布区,湿地总面积达8 000 km2。江河源区独特的生态环境孕育了种类繁多的特有动、植物种类,源区约有哺乳动物、鸟类和鱼类133、249和219种,牧草植物、药用植物、食用植物和观赏植物约800、808、80和400种,是世界海拔最高的生物多样性集中分布区。然而,由于超载放牧、盲目采挖、盗猎等不合理的开发和利用以及气候变化等诸多因素的综合影响,江河源区草地生态系统退化、高寒湿地萎缩、生物多样性锐减等生态环境危机不断加剧。正确权衡江河源区自然生物资源的短期经济价值及其所拥有的巨大生态公益和潜在开发价值,科学决策,保护江河源区自然生物资源迫在眉睫。     

Trade-Offs between Species Conservation and the Size of Marine Protected Areas

Abstract:  Moving from single-species- to ecosystem-based management requires an understanding of how community-level attributes such as diversity change with area. We used survey data from bottom trawls to examine spatial patterns of species richness in U.S. Pacific coastal fishes. Specifically, we generated and compared species–area relationships (SARs) for species classified into several groups on the basis of maximum body size, trophic level, diet, maximum depth, geographic affinity, and taxonomic order. Because SARs among groups were not parallel and z values varied significantly for several groups, groups of species were under- or overrepresented (depending on the size of the area) relative to their proportions in the entire community (i.e., entire U.S. Pacific coast). In this way, differences in SARs help demonstrate trade-offs between species representation and coastal area and suggest strategies (such as targeting the protection of habitats and locations where a particular species or groups of species are maximized) that may minimize the size of marine protected areas (MPAs) but protect diversity at the level of the community and functional group.     

长期施肥对旱地土壤杂草种子库生物多样性影响的研究

为探讨长期施肥对旱地土壤杂草种子库生物多样性的影响,我们在安徽蒙城地区的一个长期肥料试验定位监测点开展了相关研究。采用镜检法对旱地土壤表层（0～15 cm）中土壤杂草种子的种类进行鉴定并计数,记录杂草种子22种,隶属15科。不同施肥处理区杂草种子丰富度以NP1/2K区最高（14.7种）,PK区最低（10.7种）;其中陌上菜（Lindernia procumbens）、栗米草（Mollugo pentaphylla）、醴肠（Eclipta prostrata）、泽星宿菜（Lysimachia candida lindl）四种杂草的种子密度较大,分别在不同的处理区占据优势;从整个试验区来看,烟台飘拂草（Fimbristylis stauntoni）在所有处理中的密度都比较大,处于优势地位。长期不同施肥方式下,农田土壤杂草种子库的物种多样性有显著差异：PK区Shanon-Wiener指数大于其他处理区,但是Simpson优势度指数最低;NPK区Simpson优势度指数最高;PK、CK区Pielou均匀度指数大于其他处理区。田间杂草种子库的群落结构及其物种组成也发生了一定的变化,Whittaker指数表明,与不施肥处理相比较,半量的P和缺N的影响最显著,缺P次之,缺K和平衡施肥则没有显著影响。Sorenson群落相似性指数和Bray Curtis指数聚类分析结果表明,与不施肥相比较,长期施用N、P、K肥能显著改变旱地土壤杂草种子库的组成。本研究表明长期平衡施肥处理更有利于维持和保护旱地土壤杂草种子库的生物多样性。     

Knowing, Mapping and Understanding st. Lawrence Biodiversity, with Special Emphasis on Bird Assemblages

Environment Canada and the Québec Department of the Environment, partners in the St Lawrence Vision 2000 Action Plan, set out to prepare a compendium of knowledge of the flora and fauna of the St Lawrence and to identify potential conservation sites. The resulting Portrait is an Internet site that presents the current knowledge base of the river's ecological and biological diversity (http://lavoieverte.qc.ec.gc.ca/faune/biodiv/index.html). The Portrait provides information on over 5,000 species of flora and fauna. On the website, you will find a detailed ecological analysis of the richness, rarity and vulnerability of several broad groups of plant and animal species. Furthermore, you will find a list of species for each of the 700 survey units and a distribution map for 2,500 species recorded along the St Lawrence., in atlas form, along with a detailed conservation plan. The plan encompasses the most unique and heterogeneous landscapes of the St Lawrence, some of which have no protection at present. The Portrait provides an overview of the sites that are currently protected by public agencies and private-sector organisations and identifies new sites of interest for conserving biodiversity and protecting species at risk. This paper exposes the content of this extensive compendium on the biodiversity of the St. Lawrence. For conciseness, it presents some of the analyses conducted on birds to illustrate a few of the analytical approaches that were used. Then, the information on species richness and concentration areas for priority species of vascular plants, breeding birds and herpetofauna will serve to identify the terrestrial sites of significance for biodiversity. Finally, a similar approach having been applied to the aquatic environnement, we will conclude with a conservation plan that identifies the terrestrial and aquatic ecosystems, and the geographic sites where the most important elements of St. Lawrence biodiversity are concentrated. Our analysis of the biodiversity of the most thoroughly studied taxa of the St. Lawrence clearly shows the importance of wetlands, particularly those located at the mouths of rivers or within archipelagos or delta complexes, such as the groups of islands and channels found at both ends of the Montréal Archipelago. These aquatic landscapes are sites of intense biological production, combining in a small geographical area spawning, nursery and feeding grounds for a large number of fish species and breeding, rearing and foraging areas for aquatic birds. Variable flooding conditions, associated with seasonal flooding or daily tidal fluctuations, create a complex mosaic of wetland and aquatic habitats. Although wetlands occupy only a small area in comparison with terrestrial habitats, they support a large number of rare plant and animal species in relation to their size. At present, 10% of the vascular flora and 27% of the herpetofauna of the St. Lawrence are at risk. In the case of reptiles and amphibians, the situation is especially worrisome because nearly all of the most threatened species live in a narrow band along the river corridor. Not only is this the sector that is under the greatest pressure from human development, very little public land remains here, making it difficult to create protected areas. Increased participation by non-governmental organisations and individuals, through private stewardship arrangements, is an essential precondition for completing the network of conservation areas in this part of the St. Lawrence. Along the estuary and the Gulf, habitat integrity has not been affected as much by the expansion of Québec's human population. This is a vast territory, and sites have been identified with a view to making up for the deficiencies in the present network of protected sites in terms of representing biodiversity.