Understanding landholder management of river frontages: The Goulburn Broken

Summary In this paper we discuss the findings of research exploring landholder adoption of practices expected to improve the management of river frontages. This research was part of a larger project undertaken by the Goulburn Broken Catchment Management Authority (GBCMA) to assess the impacts of grazing on the condition of riparian zones in the GBCMA region. Our research employed a postal survey to a random selection of all river frontage owners in the GBCMA. Research findings highlighted the limited adoption of most current recommended practices (CRP) such as watering stock off‐stream and fencing to manage stock access to river frontages. Higher adoption of CRP (in particular fencing) was correlated with greater knowledge of river frontage function and factors affecting river frontage condition; higher importance attached to the environmental, social and economic values of frontages; non‐farming occupations; and higher confidence in the efficacy of CRP. These findings have important implications for managers and scientists. There has been a large investment in community education in the GBCMA and survey findings suggest this has been an effective strategy. At the same time, there should be changes in the approach to community education. It seems there is much to be done to improve the acceptability of fencing frontages along large rivers. Appeals to adopt CRP also need to move beyond a narrow focus on farmers and the benefits of increased agricultural production and embrace the range of landholders and the different values they attach to their frontages. Most respondents had no on‐property profit and survey data indicated that financial constraints were an important factor limiting the adoption of CRP, particularly among farmers. There was considerable interest in taking up a grant scheme that would provide a higher level of support than is usually offered by government. These findings highlight the important role of economic incentives in assisting private landholders undertake conservation work along river frontages.     

A field test of the audibility of urban versus rural songs in mountain chickadees

Anthropogenic noise can mask avian vocalizations, and several urban‐dwelling species adjust frequency or amplitude of vocalizations in ways that appear to compensate for increased noise levels. Playback studies have investigated whether receivers differentiate between signals produced by rural and urban males, but it is difficult to determine whether differential response to stimulus reflects differences in audibility versus perceived differences in male signals/condition that result from urban settlement. Here, we performed paired‐playback trials to determine whether mountain chickadees (Poecile gambeli) differentiate urban versus rural songs when both stimuli were broadcast within noise. For each playback, stimuli were played in short bouts starting at a low signal‐to‐noise ratio and increasing in relative amplitude with each successive bout. If the primary function of adjusted urban songs is propagation in noise, we hypothesized that focal males would respond sooner to urban versus rural playbacks (detect at lower signal‐to‐noise ratios). If urban songs solely encode information about the male's condition (such as increased aggression), then we predicted only a differential aggressive response to playbacks once detected. If urban songs both increase propagation and embed information on male condition, we predicted a combination of both response types. We found no difference in latency to first response in urban versus rural songs, but some evidence for differential aggression to playback dependent on both stimulus type (urban vs. rural) and local ambient noise levels; focal males in noisy (urban) sites responded aggressively to both stimulus types, whereas focal males in quiet (rural) sites responded more aggressively to urban than to rural stimuli. This context‐dependent discrimination may be the result of increased aggression in urban habitats, improved communication in noisy habitats by urban signallers and receivers, or some combination of the two.     

基于选择实验法的流域中下游居民生态补偿支付意愿及其偏好研究——以渭河流域为例

在流域生态补偿机制的建设中,相关利益主体的生态补偿意愿和行为的分析对政策的管理和执行至关重要。运用选择实验法对渭河流域中下游居民的支付意愿进行考察,通过构建Mixed Logit模型对城乡居民的支付意愿及其偏好进行实证分析。研究发现,城镇和农村居民的选择显著受到水质、河流面积/水量、水土流失情况、动物种类/数量这4个属性变量的正向影响,支付金额的负向影响;其次,城镇和农村居民对水质这一属性具有最高的支付意愿,对河流面积/水量这一属性具有次高的支付意愿,而对动物种类/数量这一属性具有最低的支付意愿;最后,城镇和农村居民的平均支付意愿分别为13.168元月^-1人^-1和9.050元月^-1人^-1,前者的支付意愿明显高于后者。     

Does it matter why we do restoration? Volunteers,offset markets and the need for full disclosure

Volunteers are behind much of the ecological restoration work done in Australia. Private landholders, environmental nongovernment organisations (ENGOs) and community groups all donate time and money to much‐needed restoration and revegetation efforts. Biodiversity offsetting has emerged as a potential source of financial support for such work. We consider the question: should it matter to practitioners of restoration, particularly landholders and volunteers, how it is financed? We argue it should, because when offsets fund restoration work, the net environmental outcome is usually intended to be neutral – not an environmental gain. This is often not clear, because only the localised environmental gain is seen by the restoration practitioner, not the associated loss. For mandated offsets, the restoration work is required to occur regardless of whether the volunteer contributes to it or not, so their contribution only replaces work that would otherwise be done by a commercial provider. We contend that informed involvement in offset provision requires full disclosure, particularly to volunteers and landholders. Unfortunately, however, such transparency does not always occur. We acknowledge that there are valid reasons why well‐informed practitioners might willingly subsidise offset provision, but they might equally choose not to. Furthermore, offsets are intended to cover the full cost of biodiversity damage, creating a disincentive for damage by developers. Yet, subsidies from offset providers work against sending market signals that reflect the true replacement cost of biodiversity. We recommend that all ENGOs, developers, offset funders and brokers commit to transparency, particularly to landholders, donors and volunteers, about the environmental impact that is to be offset and the fact that their involvement generates no additional environmental benefit, as the offset is a condition of approval for a permitted loss, much like the rehabilitation of a mine site. Providing restoration services in partnership with industry may be something that landholders, volunteers and ENGOs are happy to support. But this must be decided consciously, not through unnoticed incremental changes that contradict some volunteers’ values or donors’ understanding of an organisation's mission.     

Remnant vegetation,landholders’ values and information needs: An exploratory study in the West Australian wheatbelt

Summary An exploratory study of landholders in the central wheatbelt of Western Australia provides a useful snapshot of values, uses, management, information sources and requirements of landholders in relation to remnant native vegetation in agricultural landscapes. Landholders valued their remnant vegetation for ecological, aesthetic, functional and community reasons. Most actively managed it for nature conservation, although almost half grazed stock in their remnants. In terms of information sources and needs, the most widely used sources were Community Landcare Coordinators, other landholders and government departments. Landholders wanted hydrological, weed control and biodiversity information, plus a suite of other information. A third of landholders were characterized as having a broad, ecosystem‐based awareness compared to the other two‐thirds who had a more limited, site‐based awareness. Each group had different information needs. These findings have clear implications for information provision to landholders.     

Seasonal shifts in the assembly dynamics of benthic macroinvertebrate and diatom communities in a subtropical river

Identifying seasonal shifts in community assembly for multiple biological groups is important to help enhance our understanding of their ecological dynamics. However, such knowledge on lotic assemblages is still limited. In this study, we used biological traits and functional diversity indices in association with null model analyses to detect seasonal shifts in the community assembly mechanisms of lotic macroinvertebrates and diatoms in an unregulated subtropical river in China. We found that functional composition and functional diversity (FRic, FEve, FDis, MNN, and SDNN) showed seasonal variation for macroinvertebrate and diatom assemblages. Null models suggested that environmental filtering, competitive exclusion, and neutral process were all important community assembly mechanisms for both biological groups. However, environmental filtering had a stronger effect on spring macroinvertebrate assemblages than autumn assemblages, but the effect on diatom assemblages was the same in both seasons. Moreover, macroinvertebrate and diatom assemblages were shaped by different environmental factors. Macroinvertebrates were filtered mainly by substrate types, velocity, and COD_Mn, while diatoms were mainly shaped by altitude, substrate types, and water quality. Therefore, our study showed (a) that different biological assemblages in a river system presented similarities and differences in community assembly mechanisms, (b) that multiple processes play important roles in maintaining benthic community structure, and (c) that these patterns and underlying mechanisms are seasonally variable. Thus, we highlight the importance of exploring the community assembly mechanisms of multiple biological groups, especially in different seasons, as this is crucial to improve the understanding of river community changes and their responses to environmental degradation.     

Using biological traits to assess how urbanization filters plant species of small woodlands

Question: Which biological traits (persistence, regeneration, dispersion traits and resource requirements) may explain the distribution of woodland flora along an urban–rural gradient? Location: The study was carried out in three medium‐sized conurbations of north‐western France: Angers, Nantes and Rennes. Methods: We sampled the vegetation of 36 small woodlands of about 1.5 ha composed of non‐planted vegetation along an urban–rural gradient. We characterized the position of woodlands along the urban–rural gradient by examining adjacent land cover. By using an ordination analysis (RLQ), we analysed which traits out of –23 tested were related to the contrasted distribution of species along the urban–rural gradient. Results: Species that are more likely to be found in urban woodlands than rural woodlands have different persistence traits (higher specific leaf area, more often rosette or semi‐rosette form, less underground vegetative multiplication), resource requirements (affinity for base‐rich and fertile soils) and regeneration traits (short life‐span). Dispersion traits were not related to the distribution of species along the urban–rural gradient. Conclusions: Our approach identifies traits that can help to determine the vulnerability of forest species as a result of the environmental changes that follow urbanization. Limiting the influence of the urban environment on habitat quality (particularly disturbance and soil enrichment) is likely to be of major importance in maintaining the plant biodiversity in woodlands.     

Key biocultural values to guide restoration action and planning in New Zealand

A pluralist and cross‐cultural approach that accommodates differing values while encouraging the collaboration and social cohesion necessary for the complex task of ecological restoration is needed. We used qualitative and quantitative analyses to investigate value assigned to biocultural restoration of coastal forests in northern New Zealand by 26 interviewees from three groups (environmental managers, Māori community members, and community project leaders). Māori community members primarily emphasized the importance of Cultural Stewardship and Use in the restoration process, while placing less emphasis on Ecological Integrity. Otherwise, all participants shared common trends, culminating in three interrelated value sets: (1) Personal Engagement, (2) Connection, and (3) the generation and transfer of Knowledge & Wisdom. These values demonstrate that restoration's benefits to people and community are as significant as its reparations of ecological components. Despite differences, all stakeholders were united in a broadly common goal to restore socio‐ecological systems. Their knowledge and shared passion for conservation signal enormous promise for accelerated and effective restoration of coastal forests, if it is conducted using a pluralistic approach. Because some values expressed were intangible and complex, with cross‐cultural dimensions, current valuation tools used by ecological economists to guide management investment fail to adequately account for, in particular, Māori values of ecological restoration.     

The reconstruction of environmental rights in urban South Africa

Rapid and spatially concentrated urbanization in South Africa has brought with it significant health and safety hazards. These hazards are described and analyzed through two optics: environmental rights and community participation. The rights perspective suggests that the system of apartheid led to a collapse of rural livelihoods, driving people to the cities, while apartheid's tight control over African residential location and employment ensured that high density settlement and unemployment would follow. The resulting urban environmental degradation and health and safety hazards are a violation of the human rights of the African residents of townships and informal settlements. The community participation perspective suggests that reconstruction can be linked to development and that community-based hazard identification and mitigation can be a vehicle for kick-starting urban revitalization.     

Valuation study of urban bushland at Hartfield Park, Forrestfield, Western Australia

Summary Hartfield Park bushland represents a typical area of Perth urban bushland, and is identified as one site worthy of protection in the Western Australian Government's Bush Forever Plan. Two thirds of the Reserve is developed and parts of the remaining bushland are under threat of future development for parking and playing fields. This paper reports a study undertaken to estimate the economic value placed by the community on a specified urban bushland site using the contingent valuation method, a stated preference, non‐market valuation technique which captures both use and non‐use values. Because environmental goods such as urban bushland exist without organized markets, they are often omitted from the decision‐making process regarding the socially optimal management of resources. In estimating a valuation for Hartfield Park, it may be included in any cost–benefit analysis conducted for the site in future. A survey was conducted across the Perth metropolitan area during April 2001 that involved the mail out of 1000 questionnaires to names and addresses obtained at random from the Western Australia Electoral Roll. A 54% response rate was obtained. Regression analysis was used to predict the probability of people being willing to pay for the preservation of this urban bushland and the significant predictors of willingness to pay related to income and educational levels rather than proximity to or knowledge of the site. Willingness to pay was also estimated and the results indicate a conservative mean willingness to pay for the preservation of the bushland of $A21.60 per person per annum. Extrapolation of this figure across the total adult metropolitan community resulted in an estimated valuation of $A16.6 million. Median willingness to pay was also estimated and equalled $A4.35 per person per annum with a valuation for the total adult metropolitan community equal to $A3.3 million. Extrapolation of these mean and median figures across Perth households rather than adult individuals resulted in an estimated valuation of $A9.6 million and $A1.9 million, respectively. These figures indicate that the community value for this environmental amenity may exceed the costs of providing alternative facilities elsewhere.     

Contrasting patterns in species richness of birds,butterflies and plants along riparian corridors in an urban landscape

Aim Urbanization is a major driver of global land‐use change, substantially modifying patterns of biodiversity. Managing these impacts has become a conservation priority. The creation and maintenance of greenways, such as river corridors, is frequently promoted as a strategy for mitigating habitat fragmentation in urban areas by bringing semi‐natural habitat cover into city centres. However, there is little evidence to support this assertion. Here, we examine whether riparian zones maintain semi‐natural habitat cover in urban areas and how species richness varies along such zones. Location Sheffield, Northern England. Methods Multiple taxonomic groups (birds, butterflies, plants) were surveyed at 105 sites spanning seven riparian corridors that transect the study system. For all groups, we model the relationships between species richness and environmental variables pertinent to an urban system. To test whether riparian zones can act to maintain semi‐natural habitats within a city, we modelled the proportion of semi‐natural land cover within 250 m grid squares that do, and do not, contain a river. Results Species richness varied markedly in relation to distance from the urban core. Trends differed both between taxonomic groups and between rivers, reflecting the complex patterns of environmental variation associated with cities. This suggests that biodiversity surveys that focus on a single group or transect cannot reliably be used as surrogates even within the same city. Nonetheless, there were common environmental predictors of species richness. Plant, avian and butterfly richness all responded positively to Habitat Diversity and the latter two declined with increases in sealed surface. Main conclusions Multiple transects and taxonomic groups are required to describe species richness responses to urbanization as no single pattern is evident. Although riparian zones are an important component of the mosaic of urban habitats, we find that river corridors do not disproportionately support tree and Natural Surface Cover when compared to non‐riverine urban areas.     

基于区域城市化LUCC的人类生态过程定量研究——以上海市区典型城市化样带为例

借鉴流域研究的范例,根据上海市1987年、1995年和2003年3期Landsat5 TM遥感影像记录的土地利用／覆被数据和有关的社会经济统计数据,运用Rs和GIS技术在上海市中心西南城市边缘建立典型城市化样带。采用生态足迹法分析该样带内人类的生态供给与需求;提出一城市化区域人类生态过程的新研究方法,得出城市化过程中区域的人类生态质量指数与波动指数,并根据模型计算出的指数值,对样带区域总体及其中城乡区域在城市化中的人类生态状况进行了动态分析,以尝试对区域城市化中人类生态过程进行定量化研究。     

Response to Predation Risk in Urban and Rural House Sparrows

Habitat urbanization may change the density of predators, and it is often assumed that such changes lead to altered predation risk for urban populations of their prey. Although it is difficult to study predation hazard directly, behavior responses of prey species may be informative in inferring such habitat differences. In this study, we compared the risk‐taking behavior of urban and rural house sparrows (Passer domesticus) after simulated attacks by two of their important predators (sparrowhawk Accipiter nisus and domestic cat Felis catus). The birds were startled by moving dummies of these predators and respective control objects, and their risk taking was estimated as their latency to feed after the startle. We found that sparrows responded more strongly (had longer post‐startle feeding latencies) to sparrowhawk attacks than to the control object, and their responses differed between the habitats. First, risk taking of urban birds strongly decreased with age (older birds had longer latencies than young birds), while there was no such age difference in rural birds. Second, young urban birds responded less strongly, while older urban birds responded more strongly to the sparrowhawk than the same age groups of rural birds, respectively. We did not succeed in evoking antipredatory response by simulated cat attacks, because birds responded similarly to the dummy and the control object. Our results support that predation risk, posed at least by avian predators, is different in urban and rural habitats of house sparrows. The increased wariness of older, hence presumably more experienced, urban birds implies that sparrows may be more exposed to predation in cities.     

Shifts in reciprocal river‐riparian arthropod fluxes along an urban‐rural landscape gradient

相似文献   

基于碳排放约束的北京市社区生态效率评价

在“双碳目标”的背景下,社区作为生态文明建设的基本单元,其碳排放核算及生态效率评估尤为重要。基于家庭消费视角,采用碳排放系数法和消费者生活方式法核算社区居民碳排放,并运用超效率DEA模型评估社区生态效率,最后通过计量分析识别生态效率影响因素。研究结果显示：(1)社区居民人均碳排放的评估结果呈现出商品房社区(528.85kgCO₂/月)>单位社区(475.66kgCO₂/月)>传统社区(368.33kgCO₂/月)的关系;(2)生态效率的评估结果呈现出传统社区(111.04%)>商品房社区(108.78%)>单位社区(105.70%)的关系;(3)社区管理工作参与意愿、家庭光照条件会对社区生态效率产生积极影响;此外,年龄结构(中青年人口占比)对商品房社区的生态效率有消极影响,受教育程度的提升则会提高生态效率。进一步提出针对三类社区特点的转型发展策略,为全国不同类型社区生态转型和绿色低碳发展提供参考范式和决策支持。     

Species residency status affects model selection and hypothesis testing in freshwater community ecology

相似文献   

Rural and Urban Streams: Anthropogenic Influences and Impacts on Water and Sediment Quality

The Pirapó river watershed (Paraná State, Brazil) compounds a relatively industrialized and urbanized region, undergoing great pressure from the discharge of industrial, agricultural and domestic wastes. We evaluated the environmental quality of ten streams belonging to this watershed in April and June 2008 by performing acute and chronic toxicity tests with Daphnia similis and Ceriodaphnia silvestrii from water and sediment samples. We tested the hypothesis that the streams located in urban areas are more exposed to the influence of pollutants, than those outside the city limits. In addition, we obtained the measures of physical and chemical parameters, and identified the main polluted sources. Contrary to what was expected, the rural streams were more toxic than those located in urban area. These results demonstrate that the water bodies located in rural areas are being affected by the pollution of aquatic ecosystems as far as those found in urban areas, requiring the same attention of environmental managers in relation to its monitoring. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Meiobenthic response to river-borne benthic particulate matter – a microcosm experiment

1. Benthic communities inhabiting river–lake interfaces are confronted with temporal variation in the import of river‐borne material to the associated littoral zone. The primary objective of this study was to evaluate the exposure to river‐borne benthic particulate matter as a force shaping the meiofauna of the river–lake interface. 2. In a 2 × 2 factorial design, combinations of strongly and weakly river‐influenced communities (near or far from the river mouth) with and without river‐borne benthic particulate matter enrichment were studied in laboratory microcosms to assess the response of the heterotrophic meiobenthos to river‐borne matter. 3. Nematodes dominated both habitat types and were the only meiofaunal taxon that responded to the enrichment. 4. A strong interactive effect between experimental enrichment and location of site was observed. Whereas nematodes from the littoral habitat close to the river mouth responded to the enrichment only marginally, nematodes from the remote site were strongly affected in the presence of river‐borne particulate matter. 5. In the non‐enriched samples of the remote site, the number of nematodes increased greatly over time. Among nematode feeding types, deposit feeders dominated over chewers at the beginning of the experiment but both types were equally abundant at the end. In the presence of river‐borne matter the increase of chewers ceased and a shift in feeding type composition did not occur. 6. It was shown that for river–lake interface meiofaunal assemblages in relative proximity, the same taxon might respond differently if exposed to an external pressure, e.g. river‐borne components. These components may have a stronger influence on taxa with longer life cycles.     

Contrasting responses in community structure and phenology of migratory and non‐migratory pollinators to urbanization

Aim

Anthropogenic landscape change, such as urbanization, can affect community structure and ecological interactions. Furthermore, changes in ambient temperature and resource availability due to urbanization may affect migratory and non‐migratory species differently. However, the response of migratory species to urbanization is poorly investigated, and knowledge for invertebrates in particular is lacking. Our aim was to investigate whether there was a shift in community structure and phenology of hoverflies in urban landscapes, depending on migratory status.

Location

Switzerland.

Methods

Using a paired design, we compared urban and rural landscapes to investigate the impact of urbanization on the abundance, diversity and phenology of hoverflies. Furthermore, we tested whether migratory and non‐migratory species responded differently to urbanization.

Results

We observed a difference in the response of migratory and non‐migratory hoverfly communities. Although the abundance of hoverflies was higher in the rural ecosystem, driven by a high abundance of migratory species, there was no difference in species richness between the land use types. However, the community structure of non‐migratory species was significantly different between urban and rural ecosystems. The phenology of hoverflies differed between the two ecosystems, with an earlier appearance in the year of migratory species in urban landscapes.

Main conclusions

To our knowledge, this is the first study to investigate the response of migratory insect communities to urbanization. We demonstrated that migratory and non‐migratory hoverflies respond differently to urbanization. This highlights the importance of differentiating between trait and mobility groups to understand community assemblage patterns in anthropogenic landscapes. The differences in phenology supports the growing evidence that urbanization not only affects the phenology of vegetation, but also affects the higher trophic levels. Changes in the phenology and community composition of species as a result of anthropogenic landscape change may have important implications for the maintenance of key ecosystem functions, such as pollination.