Farmer typology, future scenarios and the implications for ecosystem service provision: a case study from south-eastern Spain

Farming communities are increasingly expected to manage their agricultural activities in ways that ensure sustainable flows of a wide range of ecosystem services for society. The land use and management choices that farmers make are dependent upon their socio-economic characteristics and background, and in turn have important implications for the landscape and associated ecosystem services. Thus, a better understanding about the linkages between the characteristics of farmers, farm management and land use is important for managing multifunctional agro-ecosystems. In this paper, we first develop a typology of farmers for Torrealvilla catchment in Murcia, Spain, according to the characteristics of their households and farm management (e.g. the farmer’s age, household income, water access, land tenure and farm labour). This analysis distinguishes six types of farmers. Secondly, we analyse the link between farmer typology and the farmers’ responses to a number of scenarios. The scenarios describe different likely changes to agriculture in the catchment in terms of environmental constraints (irrigation water availability and rainfall pattern) and environmental policy regulation (water taxation and subsidies). This exercise enables us to explore the range of future land use changes that are likely to occur in the study area. The results indicate that: rain-fed agriculture is expected to experience gradual but extensive abandonment; vegetable/fruit farming and pig/animal rearing are likely to stagnate or even decline; and growing of grapes is likely to expand. Thirdly, we qualitatively evaluate how future land use changes are likely to affect key ecosystem services in the study area including future agricultural production and associated local income generation, erosion control, maintenance of the groundwater table and various cultural services associated with a heterogeneous agro-ecosystem. Particular changes such as expansion of grape production will increase food production and local income at the cost of further depletion of the aquifer and increased risk of salinisation. The outcomes of the study highlight that, to be effective, the design of agri-environmental schemes and other government interventions (e.g. specific compulsory regulations on farming practices and associated water use) should carefully take into account the characteristics of the farmers within the area of interest, their land uses and the possible diversity of responses to policy and environmental drivers. Opportunities exist for future studies quantifying the extent of the impacts of ecosystem service provision through formal models combining farmers’ land use decision-making and spatially explicit modelling of landscape processes.     

A Methodology for Assessing Blast Protection in Explosive Ordnance Disposal Bomb Suits

To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax.

A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn.     

Design for resilience in infrastructure distribution networks

The recognition that resilience is a critical aspect of infrastructure security has caused the national and homeland security communities to ask “How does one ensure infrastructure resilience?” Previous network resilience analysis methods have generally focused on either pre-disruption prevention investments or post-disruption recovery strategies. This paper expands on those methods by introducing a stochastic optimization model for designing network infrastructure resilience that simultaneously considers pre- and post-disruption activities. The model seeks investment–recovery combinations that minimize the overall cost to a distribution network across a set of disruption scenarios. A set of numerical experiments illustrates how changes to disruption scenarios probabilities affect the optimal resilient design investments.     

The Arkansas Valley “Super Ditch”— An Analysis of Potential Economic Impacts1

McMahon, Tyler G. and Mark Griffin Smith, 2012. The Arkansas Valley “Super Ditch”— An Analysis of Potential Economic Impacts. Journal of the American Water Resources Association (JAWRA) 00(0):000‐000. 1‐12. DOI: 10.1111/jawr.12005 Abstract: In Colorado’s Arkansas River basin, urban growth and harsh farming conditions have resulted in water transfers from agricultural to urban uses. Several studies have shown that these transfers have significant secondary economic impacts associated with the removal of irrigated land from production. In response, new methods of sharing water are being developed to allow water transfers that benefit both farm and urban economies, compared with previous permanent transfers that negatively impacted surrounding farm communities. One such project currently under development is the Arkansas Valley “Super Ditch,” which is a rotational crop fallowing plan based on long‐term water leasing designed to provide an annual supply of 25,000 acre‐feet of water (31.6 Mm³). This article analyzes the net benefits of implementing the “Super Ditch” for both the farmers and the surrounding community.     

Water Stress Projections for the Northeastern and Midwestern United States in 2060: Anthropogenic and Ecological Consequences

Future climate and land‐use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast and Midwest and (2) native fish species richness (i.e., number of species) for the Upper Mississippi water resource region (UMWRR). Six alternative scenarios of climate change, land‐use change, and human population growth indicated future water supplies will, on average across the region, be adequate to meet anthropogenic demands. Nevertheless, the number of individual watersheds experiencing severe stress (demand > supplies) was projected to increase for most scenarios, and some watersheds were projected to experience severe stress under multiple scenarios. Similarly, we projected declines in fish species richness for UMWRR watersheds and found the number of watersheds with projected declines and the average magnitude of declines varied across scenarios. All watersheds in the UMWRR were projected to experience declines in richness for at least two future scenarios. Many watersheds projected to experience declines in fish species richness were not projected to experience severe anthropogenic water stress, emphasizing the need for multidimensional impact assessments of changing water resources.     

Public Participation and Local Environmental Planning: The collective action problem and the potential of social capital

Expanding the opportunities for public participation in environmental planning is not always the best option. Starting from an institutional public choice analysis of public participation in terms of the collective action problem, this paper emphasises the roots of participatory activities in the incentive structures facing potential participants. It then goes on to consider the strategies that may be adopted for encouraging greater public involvement and looks particularly to the social capital literature for suggestions of how institutional redesign may alter these incentive structures. The paper concludes by distinguishing three different modes of environmental planning, in terms of the rationale for participation, the severity of the collective action problem and the associated participatory strategy that can be adopted.     

Importance of health assessments for conservation in noncaptive wildlife

Wildlife health assessments help identify populations at risk of starvation, disease, and decline from anthropogenic impacts on natural habitats. We conducted an overview of available health assessment studies in noncaptive vertebrates and devised a framework to strategically integrate health assessments in population monitoring. Using a systematic approach, we performed a thorough assessment of studies examining multiple health parameters of noncaptive vertebrate species from 1982 to 2020 (n = 261 studies). We quantified trends in study design and diagnostic methods across taxa with generalized linear models, bibliometric analyses, and visual representations of study location versus biodiversity hotspots. Only 35% of studies involved international or cross-border collaboration. Countries with both high and threatened biodiversity were greatly underrepresented. Species that were not listed as threatened on the International Union for Conservation of Nature Red List represented 49% of assessed species, a trend likely associated with the regional focus of most studies. We strongly suggest following wildlife health assessment protocols when planning a study and using statistically adequate sample sizes for studies establishing reference ranges. Across all taxa blood analysis (89%), body composition assessments (81%), physical examination (72%), and fecal analyses (24% of studies) were the most common methods. A conceptual framework to improve design and standardize wildlife health assessments includes guidelines on the experimental design, data acquisition and analysis, and species conservation planning and management implications. Integrating a physiological and ecological understanding of species resilience toward threatening processes will enable informed decision making regarding the conservation of threatened species.     

Linking direct and indirect data on dispersal: isolation by slope in a headwater stream salamander

There is growing recognition of the need to incorporate information on movement behavior in landscape-scale studies of dispersal. One way to do this is by using indirect indices of dispersal (e.g., genetic differentiation) to test predictions derived from direct data on movement behavior. Mark-recapture studies documented upstream-biased movement in the salamander Gyrinophilus porphyriticus (Plethodontidae). Based on this information, we hypothesized that gene flow in G. porphyriticus is affected by the slope of the stream. Specifically, because the energy required for upstream dispersal is positively related to slope, we predicted gene flow to be negatively related to change in elevation between sampling sites. Using amplified DNA fragment length polymorphisms among tissue samples from paired sites in nine streams in the Hubbard Brook Watershed, New Hampshire, USA, we found that genetic distances between downstream and upstream sites were positively related to change in elevation over standardized 1-km distances. This pattern of isolation by slope elucidates controls on population connectivity in stream networks and underscores the potential for specific behaviors to affect the genetic structure of species at the landscape scale. More broadly, our results show the value of combining direct data on movement behavior and indirect indices to assess patterns and consequences of dispersal in spatially complex ecosystems.     

Herbivore vs. nutrient control of marine primary producers: context-dependent effects

Pervasive overharvesting of consumers and anthropogenic nutrient loading are changing the strengths of top-down and bottom-up forces in ecosystems worldwide. Thus, identifying the relative and synergistic roles of these forces and how they differ across habitats, ecosystems, or primary-producer types is increasingly important for understanding how communities are structured. We used factorial meta-analysis of 54 field experiments that orthogonally manipulated herbivore pressure and nutrient loading to quantify consumer and nutrient effects on primary producers in benthic marine habitats. Across all experiments and producer types, herbivory and nutrient enrichment both significantly affected primary-producer abundance. They also interacted to create greater nutrient enrichment effects in the absence of herbivores, suggesting that loss of herbivores produces more dramatic effects of nutrient loading. Herbivores consistently had stronger effects than did nutrient enrichment for both tropical macroalgae and seagrasses. The strong effects of herbivory but limited effects of nutrient enrichment on tropical macroalgae suggest that suppression of herbivore populations has played a larger role than eutrophication in driving the phase shift from coral- to macroalgal-dominated reefs in many areas, especially the Caribbean. For temperate macroalgae and benthic microalgae, the effects of top-down and bottom-up forces varied as a function of the inherent productivity of the ecosystem. For these algal groups, nutrient enrichment appeared to have stronger effects in high- vs. low-productivity systems, while herbivores exerted a stronger top-down effect in low-productivity systems. Effects of herbivores vs. nutrients also varied among algal functional groups (crustose algae, upright macroalgae, and filamentous algae), within a functional group between temperate and tropical systems, and according to the metric used to measure producer abundance. These analyses suggest that human alteration of food webs and nutrient availability have significant effects on primary producers but that the effects vary among latitudes and primary producers, and with the inherent productivity of ecosystems.     

Predicting extinctions as a result of climate change

Widespread extinction is a predicted ecological consequence of global warming. Extinction risk under climate change scenarios is a function of distribution breadth. Focusing on trees and birds of the eastern United States, we used joint climate and environment models to examine fit and climate change vulnerability as a function of distribution breadth. We found that extinction vulnerability increases with decreasing distribution size. We also found that model fit decreases with decreasing distribution size, resulting in high prediction uncertainty among narrowly distributed species. High prediction uncertainty creates a conservation dilemma in that excluding these species under-predicts extinction risk and favors mistaken inaction on global warming. By contrast, including narrow endemics results in over-predicting extinction risk and promotes mistaken inaction on behalf of individual species prematurely considered doomed to extinction.