Annual burning of semi‐natural grasslands for conservation: winners and losers among plant species

Species‐rich semi‐natural grasslands in Europe are a main target for conservation efforts, and alternative methods to the traditional management of mowing or grazing would be welcome due to the difficulties in maintaining traditional management practices. One such method proposed is burning of grassland vegetation during late winter or spring. To evaluate the effects of annual spring burning vs annual mowing on semi‐natural grassland vegetation, we compared the frequency of species in eleven field experiments in southern Sweden after ca 14 years. Out of the 88 species analyzed, five were more frequent in burnt plots compared with mowed plots (Vicia cracca, Cirsium arvense, Urtica dioica, Galium verum, Convallaria majalis). In contrast, 37 species were significantly less frequent in burnt plots compared with mowed ones, those with the largest differences being Ranunculus acris, Briza media, Veronica chamaedrys, Festuca ovina, Plantago lanceolata and Anthoxanthum odoratum. Tall‐grown species and those with preferences for N‐rich soils increased in frequency under an annual spring‐burn regime, compared with annual mowing, as did species producing larger amounts of nectar. Hence, although vegetation composition becomes more trivial with annual spring burns, there might be long‐term benefits for nectar‐feeding insects.     

Grasshopper assemblage response to a restored national park (Mountain Zebra National Park, South Africa)

Twelve grassland sites were sampled inside and outside the Mountain Zebra National Park (MZNP), South Africa to assess changes in grasshopper assemblages to grazing by indigenous mammals inside the park compared to grazing by domestic cattle outside. The MZNP has been restored from cattle-grazed farmland to indigenous mammal parkland for 62 years. The number of grasshopper species and families inside the park was not significantly different from outside the park, but the number of individuals inside the park was significantly higher. Multivariate statistics did not reveal any strong site groupings based on simple inside/outside comparisons, but there were clear groupings of sites based on vegetation characteristics and other environmental variables. The park boundary, therefore, does not significantly determine grasshopper assemblages, although intensity of grazing does. The indigenous mammals inside the park had the same effect on grasshoppers as the domestic cattle outside, and it was the level of defoliation and trampling that was important rather than the type of mammal. Intensive livestock grazing and trampling leads to bush encroachment and reduction in grass cover and/or disappearance of several grass species. In response to this pressure, grasshopper populations dropped, with localized extirpation of some species. Vegetation composition and structure, particularly grass height and percentage cover, had a significant effect on grasshopper assemblages. The MZNP is thus an area of localized, elevated grasshopper abundance in comparison with the surrounding farms, and presumably represents a situation prior to the current, intensive farming activities. Such elevated grasshopper abundances are important for maintaining soil quality and hence ecological integrity of this landscape which is poor in organics and nitrogen. The MZNP could be viewed as a centre where species with high mobility may seek refuge from anthropogenic pressures. The MZNP also serves as a reference illustrating the differences between restored-through-natural-succession and anthropogenically disturbed habitats, and compares desirable with undesirable ecosystem changes for herbivorous invertebrates such as grasshoppers.     

生物多样性资源：利用、保护与管理

生物多样性在本质上是一种具有多重价值,高度综合的资源形式,是人类社会生存与发展的物质基础,在人类社会发展过程中,生物多样性资源利用与保护之间日益表现为彼此冲突的特征,但并非不可调和。本文认为,协调二者关系,实现生物多样性资源可持续利用和区域社会经济可持续发展的根本途径是生物多样性资源管理,它由主体层,客体层和目标层构成,应该具备主体多元化,参与的广泛性,过程的动态性与持续性,尺度性与地域性和公平性等基本特征,主体层是由以人为核心的各种组织形式构成的,是从社会经济系统中分化出来的一个职能层次;客体层也就是管理的对象层,是生物多样性资源系统和社会经济系统的耦合体,目标层包括生物多样性资源的可持续利用,生态文明的构建与发展和区域社会经济的可持续发展,生态文明是生物多样性资源可持续利用和区域社会可持续发展的根本保障,其中,主体层和客体层构成了生物多样性资源管理的实体部分,而目标层则是生物多样性资源管理的参照体系,生物多样性资源管理包括管理范围界定,问题辨识,目标确定,政策制定与方案运筹,实施,监测与评价,适应性调整6个基本步骤,是一个复杂的多层次动态反馈过程,这一过程中,科学研究发挥着非常重要的作用,因此应该在加强生物多样性科学研究的同时融合科学与管理的关系,使科学成果真正转化成效的管理行为。     

Principles for linking fish habitat to fisheries management and conservation

A set of eight simple ecological and social principles is proposed that could enhance the understanding of what constitutes fish 'habitat' and, if implemented, could contribute to improved management and conservation strategies. The habitat principles are a small, interrelated sub‐set that may be coupled with additional ones to formulate comprehensive guidelines for management and conservation strategies. It is proposed that: 1) habitat can be created by keystone species and interactions among species; 2) the productivity of aquatic and riparian habitat is interlinked by reciprocal exchanges of material; 3) the riparian zone is fish habitat; 4) fishless headwater streams are inseparable from fish‐bearing rivers downstream; 5) habitats can be coupled – in rivers, lakes, estuaries and oceans, and in time; 6) habitats change over hours to centuries; 7) fish production is dynamic due to biocomplexity, in species and in habitats; 8) management and conservation strategies must evolve in response to present conditions, but especially to the anticipated future. It is contended that the long‐term resilience of native fish communities in catchments shared by humans depends on incorporating these principles into management and conservation strategies. Further, traditional strategies poorly reflect the dynamic nature of habitat, the true extent of habitat, or the intrinsic complexity in societal perspectives. Forward‐thinking fish management and conservation plans view habitat as more than water. They are multilayered, ranging from pools to catchments to ecoregions, and from hours to seasons to centuries. They embrace, as a fundamental premise, that habitat evolves through both natural and anthropogenic processes, and that patterns of change may be as important as other habitat attributes.     

The response of arbuscular mycorrhizae to fertilization, mowing, and removal of dominant species in a diverse oligotrophic wet meadow

In a wet oligotrophic meadow located in the Czech Republic, a factorial experiment with treatments consisting of fertilization, mowing, and removal of the dominant species (Molinia caerulea) was established in 1994. In 1997 Holcus lanatus, Molinia caerulea, Potentilla erecta, Prunella vulgaris, and Ranunculus auricomus were examined for arbuscular mycorrhizal (AM) hyphae, arbuscles, and vesicles three times over the season. Time had a significant effect on AM in all five species. Except for Molinia arbuscles, a modal effect occurred, with the second sampling having a greater level of AM structures than the first and the third. Fertilization had the greatest effect on AM levels by decreasing the level of Holcus hyphae and vesicles, Potentilla vesicles, Prunella hyphae, and Ranunculus hyphae and vesicles. Mowing significantly increased the number of Potentilla vesicles, and the removal of dominant species had no significant effects. Interactions between time and treatments were common. Significant effects to the arbuscle:vesicle ratio were infrequent, and those that occurred were related to changes over the season. Seasonal effects appear to have a more powerful effect on AM structures and the arbuscle:vesicle ratio than do treatment effects. In a second experiment, Ranunculus auricomus, R. acris, and R. nemorosus, sampled four times over the season, showed significant changes in AM colonization. Overall, AM structures either declined over the season or increased from April to May and then declined. There was no AM colonization response to a spring fertilization in the three species. It is postulated that the patterns observed are due to phosphorus availability and seasonal changes in soil moisture and rates of root growth and turnover.     

Forest conservation and environmental management in Nepal: a review

This paper provides information on the status of forests and environmental problems related to forestry in Nepal. It aims to integrate the conservation and sustainable management of forests as a part of environmental planning. A critical review of the main environmental problems with prioritization within the forestry sector; thorough review of all forest related documents, strategies, development plans, programs, institutional arrangements, policies mentioned in the Master Plan for Forestry Sector Nepal of 1988, and other relevant documents; identification of major gaps and constraints of forestry policy and plans and current practices of forest conservation and management have been done. The decline in forestry resources in Nepal took place in the past due to lack of appropriate policy to guide the legal, institutional and operational development for the forestry sector. Forestry policy in Nepal, in the past, was shaped by political and economic motives rather than ecological considerations. Policy formulation mechanisms exist in Nepal; however, there is an excessive delay in translating policies into legislation and then into operational rules and administrative orders. There is a need to implement the international obligations by transforming them into regulations in order to make them legally binding. The data to be generated in the coming years in the areas of forestry at both national and international levels suggest that we should revise the research priorities and strategies. Research to add value to the forest resource products has yet been neglected. More attention is required on regular monitoring and evaluation of the projects. A thorough evaluation of the programs and planning for the forestry sector in Nepal is urgently required to update the progress and revise the programs.     

Linking behavioral states to landscape features for improved conservation management

1. A central theme for conservation is understanding how animals differentially use, and are affected by change in, the landscapes they inhabit. However, it has been challenging to develop conservation schemes for habitat‐specific behaviors.
2. Here we use behavioral change point analysis to identify behavioral states of golden eagles (Aquila chrysaetos) in the Sonoran and Mojave Deserts of the southwestern United States, and we identify, for each behavioral state, conservation‐relevant habitat associations.
3. We modeled behavior using 186,859 GPS points from 48 eagles and identified 2,851 distinct segments comprising four behavioral states. Altitude above ground level (AGL) best differentiated behavioral states, with two clusters of short‐distance movement behaviors characterized by low AGL (state 1 AGL = 14 m (median); state 2 AGL = 11 m) and two associated with longer‐distance movement behaviors and characterized by higher AGL (state 3 AGL = 108 m; state 4 AGL = 450 m).
4. Behaviors such as perching and low‐altitude hunting were associated with short‐distance movements in updraft‐poor environments, at higher elevations, and over steeper and more north‐facing terrain. In contrast, medium‐distance movements such as hunting and transiting were over gentle and south‐facing slopes. Long‐distance transiting occurred over the desert habitats that generate the best updraft.
5. This information can guide management of this species, and our approach provides a template for behavior‐specific habitat associations for other species of management concern.

     

Ecosystem stability and resilience: a review of their relevance for the conservation management of lowland heaths

Ecosystem stability and the response of ecosystems to disturbance are of crucial importance for conservation management, especially when the object is to maintain and/or to restore early-successional communities. This paper provides a selective review of ecosystem stability from a conservation perspective. Existing models of ecosystem resilience are discussed in relation to the management of successional habitats. A multivariate model for measuring stability and resilience based on Canonical Correspondence Analysis (CCA) is outlined. The criteria for the model to work are explained and the model is tested on vegetation and soil data from the Dorset Heaths. The model provides a mechanism for bringing together measurements of both structure (species composition) and function (ecosystem properties, both biotic and abiotic), to measure stability and resilience of ecosystems. The model can also be used to measure the success of management in restoring communities and to provide information to conservation policy makers and land managers.     

Whole‐genome sequencing approaches for conservation biology: Advantages,limitations and practical recommendations

Whole‐genome resequencing (WGR) is a powerful method for addressing fundamental evolutionary biology questions that have not been fully resolved using traditional methods. WGR includes four approaches: the sequencing of individuals to a high depth of coverage with either unresolved or resolved haplotypes, the sequencing of population genomes to a high depth by mixing equimolar amounts of unlabelled‐individual DNA (Pool‐seq) and the sequencing of multiple individuals from a population to a low depth (lcWGR). These techniques require the availability of a reference genome. This, along with the still high cost of shotgun sequencing and the large demand for computing resources and storage, has limited their implementation in nonmodel species with scarce genomic resources and in fields such as conservation biology. Our goal here is to describe the various WGR methods, their pros and cons and potential applications in conservation biology. WGR offers an unprecedented marker density and surveys a wide diversity of genetic variations not limited to single nucleotide polymorphisms (e.g., structural variants and mutations in regulatory elements), increasing their power for the detection of signatures of selection and local adaptation as well as for the identification of the genetic basis of phenotypic traits and diseases. Currently, though, no single WGR approach fulfils all requirements of conservation genetics, and each method has its own limitations and sources of potential bias. We discuss proposed ways to minimize such biases. We envision a not distant future where the analysis of whole genomes becomes a routine task in many nonmodel species and fields including conservation biology.     

苜蓿邻作麦田地表步甲和蜘蛛种群动态及其对苜蓿刈割的响应

设计苜蓿-麦邻作与麦-麦邻作的农田界面捕食性天敌空间分布对比试验,在距离交接界面3、6、9、12、15、18、21、24和27 m处设诱集小区,采用陷阱法诱集调查地表步甲和蜘蛛种类与数量.结果表明: 不同界面麦田边缘地表步甲和蜘蛛物种多样性和多度都表现出一定的边际效应.苜蓿 麦界面15～18 m范围内边际效应明显,超过20 m, 边际效应逐渐消失.麦-麦界面的边缘效应明显弱于苜蓿 麦界面.苜蓿的刈割使苜蓿田中的天敌向邻作麦田迁移,苜蓿刈割后10 d内,邻作小麦田20 m内地表步甲和蜘蛛种类和个体数都有所增加,其中个体数的增长幅度大、速度快.绘制了苜蓿-麦界面地表步甲和蜘蛛的物种多样性和优势种(毛青步甲和星豹蛛)种群数量空间动态分布图,能直观地看出天敌由苜蓿向小麦田的迁移过程.     

Factors associated with suni distribution in Tembe Elephant Park,South Africa: implications for management and conservation of a small antelope

While small antelopes are becoming increasingly threatened, knowledge of their biology is often limited. Management recommendations are therefore frequently based on insufficient information. One of the declining small antelopes is the suni in South Africa. A reduction in sand forests as well as habitat destruction by increased nyala populations are the suggested causes of suni declines. However, no recent study has quantified the factors that underlie suni distribution in southern Africa. Here we investigate whether the vegetation types, vegetation structures or occurrences of sympatric browsers affect suni distribution within Tembe Elephant Park, South Africa. We found that vegetation type and vegetation structure interacted in their effects on suni distribution, but there were no effects of sympatric browsers. Suni were found most often in the sand forests, but were also present in closed woodland. Vegetation structure was, however, related to the local distribution of suni only in sand forest. This highlights that suni are not exclusively bound to sand forest, and also that the vegetation structure within the sand forest may be as important as the vegetation type. We suggest that the current conservation assessment of this subspecies is based on insufficient data, and that a more detailed assessment of their distribution and the factors that determine the same is critically needed.     

A comparison of management strategies for conservation with regard to population fitness

Computer simulations have been carried out tocompare, under realistic genetic models, twomethods proposed in the literature to retaingenetic diversity in conservation programmes.In a two-step method, contributions of parentsare set up to produce minimum coancestry(kinship) among the offspring, and this isindependent of the mating system subsequentlyapplied. In a single-step method,contributions and matings are decidedsimultaneously in order to minimise coancestry.The comparison is made in terms of maintainedgenetic diversity and in terms of populationfitness. We conclude that the two methodsmaintain approximately the same geneticdiversity but the latter induces higher levelsof inbreeding, reducing the fitness of thepopulation. Avoidance of close relatives'matings improves this latter method, but thefitness levels do not reach those of thetwo-step scheme. We also investigate theperformances of different mating strategies incombination with minimum coancestry (two-stepmethod), concluding that these mating systemsdo not substantially affect the effectivenessof the management. Finally, we illustrate howminimum group coancestry can be restrictedto a minimum loss of fitness, if a measure ofthis is available for the individuals.     

Husbandry protocols for the Band‐tailed pigeon,Patagioenas fasciata albilinea,at the WCS,Bronx Zoo for future conservation management programs

From 2015 to 2016 we determined the husbandry protocols involved in the captive rearing of the Band‐tailed Pigeon (BTPI), Patagioenas fascinate albilinea, for use as a tool in the future management of like extant and extinct avian taxa. Current and historical ex‐situ conservation management of BTPIs and the closely related Passenger Pigeon, Ectopistes migratorius, is limited in scope and required further examination. Focus on the BTPI within zoos and private aviculture facilities is currently lacking. New pressures on the wild populations and future examination of the parameters involved in the possible restoration of the Passenger Pigeon may rely on a complete understanding of these conservation management techniques. Here we report on the establishment of a colony of BTPIs, at the Wildlife Conservation Society (WCS), and detail the progress attained. A confiscated group of BTPIs was presented to WCS and allowed us to set up the colony, document the husbandry involved, and monitor neonatal development and the factors that influence that development. The information has provided a better understanding of the BTPI and has implications for the future conservation management of this and like species.     

Macroinvertebrate conservation in river ecosystems: Challenges,restoration strategies,and integrated management approaches

River ecosystems face growing threats from human-induced stressors, resulting in habitat degradation and biodiversity loss. Crucial to these ecosystems, macroinvertebrates maintain river health and functioning. In this review, we examine the challenges confronting macroinvertebrates, explore restoration strategies and management approaches, and shed light on knowledge gaps and future research directions. Habitat degradation, water pollution, climate change, and invasive species are discussed as key challenges. Various restoration strategies, such as in-stream habitat restoration, flow regime restoration, riparian zone restoration, and connectivity restoration, are evaluated for macroinvertebrate conservation. Integrated catchment management, adaptive management, community-based management, monitoring, and policy integration are highlighted as essential management approaches, and knowledge gaps in long-term monitoring, innovative restoration techniques, climate change resilience, and policy incorporation are identified as areas calling for further research. Ultimately, a proactive, adaptable, and cooperative approach to river management will ensure macroinvertebrate conservation and sustainable river ecosystems.     

黄土高原水土流失治理现状、问题及对策

黄土高原位于黄河中游地区,是世界上水土流失最为严重的区域之一;黄土高原水土流失治理问题历来受到国家高度关注,涌现了种类多样的水土流失治理模式,目前还缺乏对黄土高原区域尺度水土流失治理模式的总结和整理。本文总结和整理了建国以来黄土高原主要的四类水土流失治理模式,生物措施模式主要由退耕还林、荒山造林和封山育林工程组成,工程措施模式包括修建梯田和淤地坝,以及近期涌现的治沟造地工程;小流域综合治理模式主要体现在坡面、沟道系统整治,生物和工程措施相结合的特点,区域综合整理模式则强调对生态系统进行整体保护、系统修复和综合治理,达到生态、社会、经济可持续发展。基于黄土高原水土流失治理模式存在的问题,提出了黄土高原水土流失治理模式调整和优化建议,以期对黄土高原生态恢复建设和水土流失科学治理提供科学依据。     

Resilience of a high‐conservation‐value,semi‐arid grassland on fertile clay soils to burning,mowing and ploughing

In grassland reserves, managed disturbance is often necessary to maintain plant species diversity. We carried out experiments to determine the impact of fire, kangaroo grazing, mowing and disc ploughing on grassland species richness and composition in a nature reserve in semi‐arid eastern Australia. Vegetation response was influenced by winter–spring drought after establishment of the experiments, but moderate rainfall followed in late summer–autumn. Species composition varied greatly between sampling times, and the variability due to rainfall differences between seasons and years was greater than the effects of fire, kangaroo grazing, mowing or disc ploughing. In the fire experiment, species richness and composition recovered more rapidly after spring than autumn burning. Species richness and composition were similar to control sites within 12 months of burning and mowing, suggesting that removal of the dominant grass canopy is unnecessary to enhance plant diversity. Two fires (separated by 3 years) and post‐fire kangaroo grazing had only minor influence on species richness and composition. Even disc ploughing caused only a small reduction in native richness. The minor impact of ploughing was explained by the small areas that were ploughed, the once‐off nature of the treatment, and the high degree of natural movement and cracking in these shrink‐swell soils. Recovery of the composition and richness of these grasslands was rapid because of the high proportion of perennial species that resprout vegetatively after fire and mowing. There appears to be little conservation benefit from fire, mowing or ploughing ungrazed areas, as we could identify no native plant species dependent on frequent disturbance for persistence in this grassland community. However, the ability of the Astrebla‐ and Dichanthium‐dominated grasslands to recover quickly after disturbance, given favourable seasonal conditions, suggests that they are well adapted to natural disturbances (e.g. droughts, fire, flooding and native grazing).