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.     

Risk assessment of heavy metal(loid)s via Spinacia oleracea ingestion after sewage water irrigation practices in Vehari District

Environmental Science and Pollution Research - The use of sewage water as an irrigation source can be beneficial in agricultural practices, however, it may result in human health risks due to the...     

Why bees are critical for achieving sustainable development

Reductions in global bee populations are threatening the pollination benefits to both the planet and people. Whilst the contribution of bee pollination in promoting sustainable development goals through food security and biodiversity is widely acknowledged, a range of other benefits provided by bees has yet to be fully recognised. We explore the contributions of bees towards achieving the United Nation’s Sustainable Development Goals (SDGs). Our insights suggest that bees potentially contribute towards 15 of the 17 SDGs and a minimum of 30 SDG targets. We identify common themes in which bees play an essential role, and suggest that improved understanding of bee contributions to sustainable development is crucial for ensuring viable bee systems.     

New York City Environmental Justice Alliance Waterfront Justice Project

This paper reviews key challenges and opportunities addressed by the New York City Environmental Justice Alliance's (NYC-EJA) Waterfront Justice Project, a citywide campaign to promote climate resilience and sustainability in urban industrial waterfront communities of New York City. NYC-EJA is a non-profit membership-driven network linking grassroots organisations from low-income neighbourhoods and communities of colour in their struggle for environmental justice. The Waterfront Justice Project is documenting community vulnerability in the context of climate change impacts, sources of industrial pollution, and demographic and socio-economic trends. This campaign is enabling community-based organisations, environmental justice communities, city planners, local and state government agencies, local business-owners, and other stakeholders to work in partnership to achieve community resilience while advocating for local jobs and promoting best practices in pollution prevention. New York City's waterfront policies ease the siting and clustering of public infrastructure, water pollution control plants, waste transfer stations, energy facilities, and heavy manufacturing uses in six areas designated as Significant Maritime and Industrial Areas (SMIAs). The SMIAs are located in environmental justice communities, largely low-income communities and communities of colour, in the South Bronx, Brooklyn, Queens, and Staten Island. New York City's local waterfront land use and zoning policies create cumulative risk exposure not only to residents and workers in the host waterfront communities, but also, in the event of storm surge or sea-level rise, to neighbouring, upland communities.     

A double‐edged sword: Realities of artisanal and small‐scale mining for rural people in the Alaotra region of Madagascar

A growing number of people are entering the artisanal and small‐scale mining (ASM) sector worldwide. In Madagascar, millions of individuals depend on this informal activity. Through a case study in the Alaotra‐Mangoro region of Madagascar, our research aimed to understand the “bottom‐up” dynamics and ripple effects of the sector, by looking at the realities for rural communities where inhabitants are both directly and indirectly affected by ASM. We were interested in community members' and miners' perceptions of the socio‐economic and environmental impacts of ASM, and in identifying the factors attracting people living in one of the country's agricultural hubs to this activity. Our results show a wide diversity of push and pull factors leading people to enter the sector. Although many positive impacts of ASM exist for miners and communities within the vicinity of mines, most miner participants considered themselves worse off since starting to mine, highlighting the high risk and low probability of return of ASM. ASM's potential for local and national development will remain squandered if its negative impacts continue to go unmanaged. Accounting for local contexts and the ripple effects of ASM will be crucial in achieving safety and security for miners, and to tap into the benefits it may offer communities while minimising environmental damage.     

Quantitative and Molecular Genetic Variation in Captive Cotton-Top Tamarins (Saguinus oedipus)

Most genetic surveys of captive and endangered populations are carried out with single gene characters bearing no direct relationship to life history or other features for which genetic variation needs to be maintained. Quantitative genetic estimates of heritable variation for life-history traits may be a more direct and appropriate measure of genetic variation for some conservation purposes. Furthermore, recent theoretical and empirical results indicate that genetic variation measured on these two levels may not be concordant. We analyzed heterozygosity at 41 allozyme loci and heritability for body weight in captive cotton-top tamarins ( Saguinus oedipus ) from the Marmoset Research Center of the Oak Ridge Associated Universities in order to compare these two levels of genetic variation. Cotton-top tamarins are a highly endangered species native to Colombia. Many animals currently reside in research facilities and zoological parks. A total of 106 animals were used in the isozyme survey, while data on 364 animals contributed to the quantitative genetic study of body weight. We found a very low average heterozygosity ( H = 1%) for this colony. Body weight was moderately and significantly heritable ( h ² = 35%). This heritability is within the normal range for natural animal populations. The finding of biologically significant levels of heritability in a population with abnormally low allozyme heterozygosity illustrates the point that low levels of allozyme heterozygosity should not be taken as an indication of overall lack of genetic variation in important quantitative characters such as life-history traits. Genetic variation required for adaptation of species to future environmental challenges can exist despite low levels of enzyme heterozygosity.     

Assessing climate change and health vulnerability at the local level: Travis County,Texas

We created a measure to help comprehend population vulnerability to potential flooding and excessive heat events using health, built environment and social factors. Through principal component analysis (PCA), we created non‐weighted sum index scores of literature‐reviewed social and built environment characteristics. We created baseline poor health measures using 1999–2005 age‐adjusted cardiovascular and combined diabetes and hypertension mortality rates to correspond with social–built environment indices. We mapped US Census block groups by linked age‐adjusted mortality and a PCA‐created social–built environment index. The goal was to measure flooding and excessive heat event vulnerability as proxies for population vulnerability to climate change for Travis County, Texas. This assessment identified communities where baseline poor health, social marginalisation and built environmental impediments intersected. Such assessments may assist targeted interventions and improve emergency preparedness in identified vulnerable communities, while fostering resilience through the focus of climate change adaptation policies at the local level.     

Modelling the impacts of strategic tree plantings on salt loads and flows in the Macquarie river catchment,NSW, Australia

In Australia, problems of dryland and stream salinity have recently become the focus of a National Action Plan. In many river catchments, preliminary stream salt load and salinity targets have been set to define maximum permissible export levels in 2015. Afforestation has been proposed as a strategy for meeting these targets, although several studies suggest that widespread commercial tree plantations are likely to deliver net dis-benefits. However, the impacts on stream salt loads of more localised tree plantings in high salt yielding areas have not been quantified. In this paper we use a simple empirical model to predict the effects of various strategic and non-strategic tree planting scenarios on flows and salt loads in the mid-Macquarie catchment, New South Wales. A simple salt routing model is then used to estimate the effect of these changes on salt loads at the end-of-valley monitoring site for the Macquarie catchment. Results suggest that widespread land management interventions will be required to meet the preliminary salt load targets for this catchment. On their own, small-scale, strategic tree planting in high salt export areas of the mid-Macquarie area will not have a significant impact on salt loads at the end-of-valley monitoring site. While widespread tree plantings may reduce salt loads in the longer term, they are likely to cause streamflow losses in the shorter term. Thus, stream salinities are expected to rise initially, due to the different response times of groundwater and surface water systems to land use change.     

Encounter rate and task allocation in harvester ants

As conditions change, social insect colonies adjust the numbers of workers engaged in various tasks, such as foraging and nest work. This process of task allocation operates without central control; individuals respond to simple, local cues. This study investigates one such cue, the pattern of an ant's interactions with other workers. We examined how an ant's tendency to perform midden work, carrying objects to and sorting the refuse pile of the colony, is related to the recent history of the ant's brief antennal contacts, in laboratory colonies of the red harvester ant, Pogonomyrmex barbatus. The probability that an ant performed midden work was related to its recent interactions in two ways. First, the time an ant spent performing midden work was positively correlated with the number of midden workers that ant had met while it was away from the midden. Second, ants engaged in a task other than midden work were more likely to begin to do midden work when their rate of encounter per minute with midden workers was high. Cues based on interaction rate may enable ants to respond to changes in worker numbers even though ants cannot count or assess total numbers engaged in a task. Received: 1 July 1998 / Accepted: 15 November 1998