Growth of the Decision Tree: Advances in Bottom‐Up Climate Change Risk Management

There has recently been a return in climate change risk management practice to bottom‐up, robustness‐based planning paradigms introduced 40 years ago. The World Bank's decision tree framework (DTF) for “confronting climate uncertainty” is one incarnation of those paradigms. In order to better represent the state of the art in climate change risk assessment and evaluation techniques, this paper proposes: (1) an update to the DTF, replacing its “climate change stress test” with a multidimensional stress test; and (2) the addition of a Bayesian network framework that represents joint probabilistic behavior of uncertain parameters as sensitivity factors to aid in the weighting of scenarios of concern (the combination of conditions under which a water system fails to meet its performance targets). Using the updated DTF, water system planners and project managers would be better able to understand the relative magnitudes of the varied risks they face, and target investments in adaptation measures to best reduce their vulnerabilities to change. Next steps for the DTF include enhancements in: modeling of extreme event risks; coupling of human‐hydrologic systems; integration of surface water and groundwater systems; the generation of tradeoffs between economic, social, and ecological factors; incorporation of water quality considerations; and interactive data visualization.     

Biota Connect Aquatic Habitats throughout Freshwater Ecosystem Mosaics

Freshwater ecosystems are linked at various spatial and temporal scales by movements of biota adapted to life in water. We review the literature on movements of aquatic organisms that connect different types of freshwater habitats, focusing on linkages from streams and wetlands to downstream waters. Here, streams, wetlands, rivers, lakes, ponds, and other freshwater habitats are viewed as dynamic freshwater ecosystem mosaics (FEMs) that collectively provide the resources needed to sustain aquatic life. Based on existing evidence, it is clear that biotic linkages throughout FEMs have important consequences for biological integrity and biodiversity. All aquatic organisms move within and among FEM components, but differ in the mode, frequency, distance, and timing of their movements. These movements allow biota to recolonize habitats, avoid inbreeding, escape stressors, locate mates, and acquire resources. Cumulatively, these individual movements connect populations within and among FEMs and contribute to local and regional diversity, resilience to disturbance, and persistence of aquatic species in the face of environmental change. Thus, the biological connections established by movement of biota among streams, wetlands, and downstream waters are critical to the ecological integrity of these systems. Future research will help advance our understanding of the movements that link FEMs and their cumulative effects on downstream waters.     

Effect of arsenic contaminated irrigation water on Lens culinaris L. and toxicity assessment using lux marked biosensor

Contamination of irrigation water represents a major constraint to Bangladesh agriculture, resulting in elevated levels in the terrestrial systems. Lux bacterial biosensor technology has previously been used to measure the toxicity of metals in various environmental matrices. While arbuscular mycorrhizal fungi have their most significant effect on phosphorus uptake, but showed alleviated metal toxicity to the host plant. The study examined the effects of arsenic and inoculation with an arbuscular mycorrhizal fungus, Glomus mosseae, on lentil (Lens culinaris L. cv. Titore). Plants were grown with and without arbuscular mycorrhizal inoculum for 9 weeks in a sand and terra-green mixture (50:50, V/V) and watered with five levels of arsenic (0, 1, 2, 5, 10 mg As/L arsenate). The results showed that arsenic addition above 1 mg/L significantly reduced percentage of mycorrhizal root infection. On further analysis a close relationship was established with the vegetative and reproductive properties of lentil (L. culinaris) plants compared to the percentage bioluminescence of the soil leachate. However, arbuscular mycorrhizal fungal inoculation reduced arsenic concentration in roots and shoots. Higher concentrations of arsenic (5, 10 mg As/L arsenate) reduced the mycorrhizal efficiency to increase phosphorus content and nitrogen fixation. Therefore, this study showed that increased concentration of arsenic in irrigation water had direct implications to the lentil (L. culinaris) plants overall performance. Moreover the use of bioassay demonstrated that mycorrhiza and clay particle reduced arsenic bioavailability in soil.     

Assessing the susceptibility of societies to droughts: a political science perspective

In this article we develop a concept for the assessment of state’s susceptibility to drought based on a political science perspective. Different sources of capacities and sensitivities need to be taken into account to assess the overall susceptibility of states as political systems. We argue that the overall susceptibility of a society depends on an interplay of state capacity and readiness as main elements of political susceptibility, wealth and economic sensitivity as elements of economic susceptibility and the degree of social integration. To transform the conceptual model into a susceptibility assessment we developed an inference model in order to generate quantitative indices. For this purpose we apply fuzzy set theory using data from our case study regions, namely Andhra Pradesh (India), the Volga region (Russia) and (Southern) Portugal. The resulting computed trends for Portugal suggest that the society will be able to deal even with severe natural conditions due to existing political, economic, and social conditions. The assessment results for the Indian and Russian case study regions, in contrast, give reason for precaution since the occurrence of drought-induced crisis events seems much more likely in the light of more crucial, overall conditions, namely lower degrees of state capacity and readiness as well as, in the case of India, a high economic susceptibility. However, further improvements are possible given the improved availability of data and the integration of more qualitative information. Additionally, the expansion to further case study regions could help validate the overall concept.     

Stable isotopes (δ18O and δ13C) in Spirula spirula shells from three major oceans indicate developmental changes paralleling depth distributions

Stable isotopes (δ¹⁸O and δ¹³C) were measured in successive chambers of the aragonitic shells of the small deep-sea squid Spirula spirula (Linnaeus 1758) (class Cephalopoda, subclass Coleoidea, order Sepioidea, family Spirulidae) to determine whether their depth distributions change with age. The spiral shells, ranging in diameter from 18 to 23 mm (30–38 chambers), were collected between 2000 and 2006 from beaches in six widely separated locations in three oceans, the Atlantic (Tobago and Canary Islands), Indian (Madagascar, Maldives, and Perth, Australia), and Pacific Oceans (Ulladulla, Australia). The patterns for both isotopes were highly correlated in specimens from all six sites. The δ¹⁸O data suggest that after hatching at depths >1,000 m at temperatures of 4–6°C, the squid migrate into shallower, warmer waters at 12–14°C at depths of 400–600 m. Subsequently, the increasing δ¹⁸O values suggest a migration back into somewhat cooler, deeper habitats. The δ¹³C values also revealed three ontogenetic stages in all six specimens, including a major shift from positive to negative values, which probably corresponds to sexual maturation, the initiation of reproduction, and concomitant changes in diet. In three of the six specimens (from Tobago, Canary Islands, and Maldives) a fourth embryonic stage (not detected in the oxygen data) was accompanied by markedly less positive δ¹³C values in the first few chambers. These data, combined with the scanty life history information from previous studies of S. spirula, can be used to compare the habitat requirements of related extant and fossil cephalopod genera. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The effect of deoxynivalenol on the secretion activity,proliferation and apoptosis of porcine ovarian granulosa cells in vitro

The aim of this in vitro study was to examine the secretion activity, markers of proliferation and apoptosis in porcine ovarian granulosa cells (GCs) after deoxynivalenol (DON) addition. Ovarian granulosa cells were incubated with DON for 24h: 10, 100 and 1000 ng/mL, while the control group received no DON. The secretion of insulin-like growth factor I (IGF–I) and progesterone was determined by radioimmunoassay (RIA) and expression of cyclin B1, PCNA and caspase-3 by immunocytochemistry. IGF–I release by GCs was inhibited by DON, while progesterone release and the expression of cyclin B1 was stimulated by DON (at 1000 ng/mL but not at 10 and 100 ng/mL). PCNA expression was stimulated by DON (at 100 and 1000 ng/mL but not at 10 ng/mL). Caspase-3 expression was not influenced by DON treatment (at all doses). In conclusion, our results indicate, (1) a direct effect of DON on secretion of growth factor IGF-I and steroid hormone progesterone, (2) expression of markers of proliferation (cyclin B1 and PCNA) but not on the (3) expression of marker of apoptosis (caspase-3) in porcine ovarian granulosa cells. This in vitro study suggests the dose-dependent association of DON on porcine ovarian functions.     

Establishment patterns in a secondary tree line ecotone

On semi-open pre-alpine fen pastures Alder encroachment creates a dynamic mosaic of grassland and woodland, which is rich in ecotones from fen to Carr. The structural diversity in colonisation patterns of Alder on fens suggests a dependency on multiple environmental drivers. Unidirectional progressive ecotone development provides an opportunity to address a current deficit in understanding successional patterns, i.e. process-pattern relationships in a multiple factor regime.We developed an individual-based model of Alder establishment on fen grassland to investigate the dependency of encroachment patterns upon seed production, dispersal distances and safe site availability. The purpose of the model is to provide a causal understanding of establishment patterns of Alder. In the model, all life processes of Alder individuals were parameterised with field data. This allowed us to strictly perform bottom-up simulations and successfully check plausibility by comparing simulated establishment patterns of cohorts with observed ecotone structures.Simulation results show that establishment patterns strongly depend on environmental drivers. Spatial progression of Alder encroachment and width of ecotones, respectively, mainly depend on wind speed during seed dispersal. Dense establishment of Alder leading to community change from fen grassland to Carr, requires windows of opportunity, which are defined by the rare coincidence of widespread dispersal, high seed production and favorable establishment conditions. Life-history traits of Alder (mast year cycle, high seed weight, weak establishment in fen) spatially and temporarily constrain the encroachment process. The structural diversity of long-term encroachment patterns is explained by the event-driven character of encroachment.Modelling individual establishment pathways of seedlings starting from germination revealed an endogenous stochasticity in establishment patterns emerging from low seed densities in the tail of the dispersal function. We conclude an inherent stochastic structure of dispersal-limited tree line ecotones, which limits reconstruction of processes from patterns.In order to describe long-term successional patterns of Alder encroachment at landscape scale, we propose the combination of two concepts: deterministic “patch-movement” of Alder woodland driven by continuous ecotone migration together with rare and stochastic “infiltration” of single Alder trees into open fen grasslands. Conservation management can control predictable “patch-movement” by cutting off maturing saplings around existing Alder woods. But the preservation of the actual large proportion of open grassland in fen pastures from infiltrating Alder seedlings and from the subsequent shift of the pasture to a densely wooded state would require mowing additionally to extensive grazing.     

Ecological Success in Stream Restoration: Case Studies from the Midwestern United States

Despite rapid growth in river restoration, few projects receive the necessary evaluation and reporting to determine their success or failure and to learn from experience. As part of the National River Restoration Science Synthesis, we interviewed 39 project contacts from a database of 1,345 restoration projects in Michigan, Wisconsin, and Ohio to (1) verify project information; (2) gather data on project design, implementation, and coordination; (3) assess the extent of monitoring; and (4) evaluate success and the factors that may influence it. Projects were selected randomly within the four most common project goals from a national database: in-stream habitat improvement, channel reconfiguration, riparian management, and water-quality improvement. Roughly half of the projects were implemented as part of a watershed management plan and had some advisory group. Monitoring occurred in 79% of projects but often was minimal and seldom documented biological improvements. Baseline data for evaluation often relied on previous data obtained under regional monitoring programs using state protocols. Although 89% of project contacts reported success, only 11% of the projects were considered successful because of the response of a specific ecological indicator, and monitoring data were underused in project assessment. Estimates of ecological success, using three criteria from Palmer and others (2005), indicated that half or fewer of the projects were ecologically successful, markedly below the success level that project contacts self-reported, and sent a strong signal of the need for well-designed evaluation programs that can document ecological success.