Beyond ‘trees are good’: Disservices,management costs,and tradeoffs in urban forestry

The provision of ecosystem services is a prominent rationale for urban greening, and there is a prevailing mantra that ‘trees are good’. However, understanding how urban trees contribute to sustainability must also consider disservices. In this perspective article, we discuss recent research on ecosystem disservices of urban trees, including infrastructure conflicts, health and safety impacts, aesthetic issues, and environmentally detrimental consequences, as well as management costs related to ecological disturbances and risk management. We also discuss tradeoffs regarding species selection and local conservation concerns, as well as the central role of human perception in the interpretation of ecosystem services and disservices, particularly the uncritical assertion that ‘everybody loves trees’. Urban forestry decision-making that fails to account for disservices can have unintended negative consequences for communities. Further research is needed regarding life cycle assessments, stakeholder decision-making, return-on-investment, and framings of services and disservices in urban forestry.     

Ecologically Functional Floodplains: Connectivity,Flow Regime,and Scale1

Opperman, Jeffrey J., Ryan Luster, Bruce A. McKenney, Michael Roberts, and Amanda Wrona Meadows, 2010. Ecologically Functional Floodplains: Connectivity, Flow Regime, and Scale. Journal of the American Water Resources Association (JAWRA) 46(2):211-226. DOI: 10.1111/j.1752-1688.2010.00426.x Abstract: This paper proposes a conceptual model that captures key attributes of ecologically functional floodplains, encompassing three basic elements: (1) hydrologic connectivity between the river and the floodplain, (2) a variable hydrograph that reflects seasonal precipitation patterns and retains a range of both high and low flow events, and (3) sufficient spatial scale to encompass dynamic processes and for floodplain benefits to accrue to a meaningful level. Although floodplains support high levels of biodiversity and some of the most productive ecosystems on Earth, they are also among the most converted and threatened ecosystems and therefore have recently become the focus of conservation and restoration programs across the United States and globally. These efforts seek to conserve or restore complex, highly variable ecosystems and often must simultaneously address both land and water management. Thus, such efforts must overcome considerable scientific, technical, and socioeconomic challenges. In addition to proposing a scientific conceptual model, this paper also includes three case studies that illustrate methods for addressing these technical and socioeconomic challenges within projects that seek to promote ecologically functional floodplains through river-floodplain reconnection and/or restoration of key components of hydrological variability.     

Epa Looks At “Fugitive Emissions”

The various aspects of two similar but indeed different air pollution problems are discussed. Both fugitive emissions (industrial) and fugitive dust emissions represent problems affecting attainment of national standards. Both are difficult to quantify so as to determine the relative magnitude of the problem. Both have been generally overlooked in the past in relation to developing an effective and widespread air pollution control program. Both problems will generally require the use of non-conventional air pollution control measures. Both are also becoming the subject of more intensive investigation as more knowledge is being gathered to implicate such emissions as significant air pollution problems.     

An Ecology of Prestige in New York City: Examining the Relationships Among Population Density,Socio-economic Status,Group Identity,and Residential Canopy Cover

Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City’s property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont’s Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas’ Potential Rating Index for Zipcode Markets (PRIZM?) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability.     

Life history of the sandy-beach amphipod Neohaustorius schmitzi (Crustacea: Haustoriidae)

Neohaustorius schmitzi Bousfield, the dominant macroscopic invertebrate on sandy beaches in North Carolina, USA, is strictly intertidal, and distributed from mean low tide to high tide, with an average density of 790/m². Location of greatest densities within the intertidal zone is dependent upon season and sex. An aggregated distribution is shown. N. schmitzi has 2 generations/year: a winter generation which lives about 8 months, and a summer generation which lives about 4 months. The reproductive season extends from February through October, with spring and summer peaks. Each female appears to produce only 1 brood of young. The number of young ranges from 2 to 14, depending upon the length and generation of the female.     

The influence of mercury on the burrowing behaviour ofCorophium volutator

The burrowing behaviour ofCorophium volutator (Pallas) has been recorded in sediments treated with seawater solutions of 0.001, 0.1, 10, and 1000 ppm HgCl₂. Heterotrophic sediment bacteria have also been counted. Non-choice and choice experiments have been conducted. In non-choice experiments no individuals burrowed in the sediment treated with 1000 ppm HgCl₂ solutions. The same numbers of individuals burrowed in the sediments treated with 0.001, 0.1, and 10 ppm HgCl₂ solutions as in the control. Bacterial numbers were lower in the sediments treated with 10 and 1000 ppm HgCl₂ solutions. Hence, a mercury concentration that killed bacteria (10 ppm) did not inhibit burrowing. In choice experiments, individuals avoided all the mercury-treated sediments, particularly that treated with 1000 ppm HgCl₂ solution. Bacterial numbers were only lower than the control in the sediments treated with 10 and 1000 ppm HgCl₂ solutions. Hence, individuals avoided treated sediments (0.001, 0.1 ppm HgCl₂) in which no bacterial mortality had occurred.     

Forests in the time of peace

ABSTRACT

The signing of Colombia’s peace agreement in 2016 signaled the end of a decades-long war between the government and the FARC (Las Fuerzas Armadas Revolucionarias de Colombia), but also an emerging assault against the country’s forests. This article aims to understand the interactions between forests and peace. In doing so, it traces landscape transformations of deforestation and possibilities for making landscapes livable in the midst of disturbance. Drawing on field research, including interviews and participant observation carried out in Colombia from 2016 to 2018, it reveals how deforestation is driven by ongoing colonization and land grabbing, mostly dedicated to extensive cattle ranching, coca cultivation, and campesinos’ transition to ‘licit’ agricultural alternatives. The article also shows how emerging coordination among farmers and forests following forest disturbance contributes to an interpretation of peace in which forests are integral. The article concludes with a call to incorporate forests in the construction of peace.     

Quantifying iridescent coloration in animals: a method for improving repeatability

Quantification of animal colors is important to a variety of fields of research, especially those dealing with visual communication and sexual selection. Most animal colors are easily measured using well-established spectrophotometric techniques. However, the unique characteristics of iridescent colors present particular challenges and opportunities to quantify novel color metrics. Due to the fine-scale angle dependence of iridescent coloration, color metrics, such as hue and brightness, must be measured using methods that allow for repeatable comparison across individuals (e.g., by carefully controlling and measuring viewing geometry). Here, we explain how the optical characteristics of iridescent colors should be considered when developing measurement techniques, describe the pitfalls of some commonly used techniques, and recommend improved methods and metrics (angular degree of color change and breadth of reflectance) for quantifying iridescent color. In particular, most studies of iridescent birds to date have used less than ideal procedures and have not provided repeatability estimates for their methods. For example, we demonstrate here that measuring coloration from overlapping patches of iridescent feathers may be problematic, and we argue against methods that do not carefully control viewing geometry. We recommend measuring iridescence at maximal reflectance angles using an apparatus that allows for sample rotation, and we compare this technique to some other commonly used methods using iridescent gorget and crown feathers from Anna’s hummingbirds (Calypte anna). Our apparatus allows for the quantification of angular color change, and we found that maximal reflectance measurements using single feathers are highly repeatable both within feather samples and among samples within an individual.