2011 Stockholm water prize laureate highlights lake ecosystem dangers and opportunities

Stockholm Water Perspectives

2011 Stockholm water prize laureate highlights lake ecosystem dangers and opportunities     

Combining palaeolimnological and limnological approaches in assessing lake ecosystem response to nutrient reduction

1. Palaeolimnological data and limnological time‐series data are highly complementary. Sediment records extend time‐scales, integrate subannual variability and expand the range of sites that can be studied, but they suffer from taphonomic biases and occasionally from uncertain chronology. Observational time‐series data, on the other hand, are highly resolved but are very limited in extent both in space and time. 2. Palaeolimnological and observational data‐sets need to be combined in oligotrophication research to establish (i) the past and present status of lakes needed to identify reference conditions; (ii) changes in ecosystem state; (iii) responses to nutrient reduction; and (iv) the potential role of other factors (e.g. additional stressors, climate change) that might confound predictions of future state.     

Empirical modelling of lake water-temperature relationships: a comparison of approaches

1.  As a result of the role that temperature plays in many aquatic processes, good predictive models of annual maximum near-surface lake water temperature across large spatial scales are needed, particularly given concerns regarding climate change. Comparisons of suitable modelling approaches are required to determine their relative merit and suitability for providing good predictions of current conditions. We developed models predicting annual maximum near-surface lake water temperatures for lakes across Canada using four statistical approaches: multiple regression, regression tree, artificial neural networks and Bayesian multiple regression.
2.  Annual maximum near-surface (from 0 to 2 m) lake water-temperature data were obtained for more than 13 000 lakes and were matched to geographic, climatic, lake morphology, physical habitat and water chemistry data. We modelled 2348 lakes and three subsets thereof encompassing different spatial scales and predictor variables to identify the relative importance of these variables at predicting lake temperature.
3.  Although artificial neural networks were marginally better for three of the four data sets, multiple regression was considered to provide the best solution based on the combination of model performance and computational complexity. Climatic variables and date of sampling were the most important variables for predicting water temperature in our models.
4.  Lake morphology did not play a substantial role in predicting lake temperature across any of the spatial scales. Maximum near-surface temperatures for Canadian lakes appeared to be dominated by large-scale climatic and geographic patterns, rather than lake-specific variables, such as lake morphology and water chemistry.     

A system for lake ecosystem indices

There is a growing awareness of the need to develop a more rational structure for scientific decision-making in the environmental sphere. The aim of this paper is to present an outline to a system for ecosystem indices (or indicators). This work is based on a holistic ecosystem perspective and the aim is to present an overall concept rather than practical results. One of the purposes of ecosystem indices is to give politicians and the general public a more easily understandable account of the environmental status and how it changes. An ecosystem index should be not only simple and concise, scientifically relevant and practical, but also economically feasible. This approach uses several important concepts, like target organisms, target ecosystems, environmental sensitivity, and environmental cost/benefit analyses related to remedial measures. Some of the ideas brought forward in this work may be unrealistic because of the complexities involved in establishing simple, practical and meaningful ecological indices. Still, the benefits of establishing even crude environmental indicators for certain ecosystems are so great, that this path is well worth pursuing.     

Challenges in integrating the concept of ecosystem services and values in landscape planning,management and decision making

Despite the growing body of literature on ecosystem services, still many challenges remain to structurally integrate ecosystem services in landscape planning, management and design. This paper therefore aims to provide an overview of the challenges involved in applying ecosystem service assessment and valuation to environmental management and discuss some solutions to come to a comprehensive and practical framework.First the issue of defining and classifying ecosystem services is discussed followed by approaches to quantify and value ecosystem services. The main part of the paper is focussed on the question how to analyze trade-offs involved in land cover and land use change, including spatial analysis and dynamic modelling tools. Issues of scale are addressed, as well as the question how to determine the total economic value of different management states.Finally, developments and challenges regarding the inclusion of ecosystem services in integrative landscape planning and decision-making tools are discussed.It is concluded that the ecosystem service approach and ecosystem service valuation efforts have changed the terms of discussion on nature conservation, natural resource management, and other areas of public policy. It is now widely recognized that nature conservation and conservation management strategies do not necessarily pose a trade-off between the “environment” and “development”. Investments in conservation, restoration and sustainable ecosystem use are increasingly seen as a “win-win situation” which generates substantial ecological, social and economic benefits.     

Stochastic modelling of nutrient loading and lake ecosystem response in relation to submerged macrophytes and benthivorous fish

SUMMARY 1. The strong stabilising effect of increased submerged macrophytes (charophytes) and benthivorous fish reduction on the clear water state was shown for shallow Lake Veluwe and Lake Wolderwijd. 2. The first two links in the chain of relationships from external phosphorus (P) loading to in‐lake total‐P concentrations to chlorophyll a concentrations to water transparency, showed a significant correlation with the areal fraction of coverage with charophytes. Higher coverages lead to (i) lower ratios of the in‐lake total‐P concentration compared with the volume weighted average concentration in the inlet water, indicating a higher retention of P in the presence of charophytes (ii) lower chlorophyll a to total‐P ratios, indicating a positive effect of charophytes on top‐down control of algae, and (iii) higher water transparency because of lower algal turbidity. Transparency further improved as a result of benthivorous fish reduction and a significant positive correlation between non‐algal turbidity and benthivorous fish biomass. 3. A model was developed taking into account the inherent variability in precipitation and uncertainties in the empirical relationships determining phosphorus export from stream catchments and other sources and eutrophication variables in the receiving lakes. The model was used to compute (i) probability distributions for in‐lake total‐P, chlorophyll a and Secchi Disc transparency in relation to the coverage with charophytes and benthivorous fish biomass, and (ii) exceedence probabilities with respect to critical values for in‐lake total‐P and water transparency for several management scenarios. 4. The effects of an expected rise in external nutrient loading on the in‐lake total‐P and chlorophyll a concentrations and on water transparency can be compensated for by two proposed control measures: (i) extended treatment at a waste water treatment plant directly discharging into Lake Veluwe, and (ii) diverting the outlet of a stream draining a catchment with high fertilisation. The minimal internal charophyte coverage needed to sufficiently stabilise the clear water state and to meet with the objective of a summer mean water transparency of at least 1 m was estimated at well over 30% of the lake area, while the benthivorous fish stock should be maintained at the present level of c. 20 kg ha^?1.     

Plant growth modelling without integrating mechanisms

The integration of root and shoot activity for resource acquisition and allocation is a central problem both in experimental physiology and in mathematical growth modelling. A key feature in all proposed solutions is the mechanism by which roots and shoot communicate their resource status, their needs or their demands. In experimental studies, chemical messengers (hormones or nutrients) have been central. In mathematical models, partitioning or productivity functions of one form or another have been incorporated to fill a similar role. In this paper, the central hypothesis is that growth and resource allocation can be based solely on local, internal, non-structural resource concentrations and local kinetic rules, without the need for additional mechanisms to integrate activities at the organis-mal level. The specific objective was to develop a formal model using the classical two-compartment, two-resource framework which did not include direct intercompartmental coordinating or communicating mechanisms or resource partitioning functions. The formalization effort was successful based on two criteria. First, the ‘plants’ grow at steady and balanced rates when ‘growth conditions’ are constant; and second, challenged with experimental manipulations such as pruning or limitations in resource acquisition, their growth responses mimic those of real plants. Analysis of the results indicates that the complex integrated growth patterns of the modelled plants are emergent properties – having no direct or indirect mechanistic basis – of the simple system. They imply that similar ‘mechanism-less’ integration is possible in real plants as an emergent property of strictly local, cellular-level activities.     

Malaria in India: Challenges and opportunities

India contributes about 70% of malaria in the South East Asian Region of WHO. Although annually India reports about two million cases and 1000 deaths attributable to malaria, there is an increasing trend in the proportion of Plasmodium falciparum as the agent. There exists heterogeneity and variability in the risk of malaria transmission between and within the states of the country as many ecotypes/paradigms of malaria have been recognized. The pattern of clinical presentation of severe malaria has also changed and while multi-organ failure is more frequently observed in falciparum malaria, there are reports of vivax malaria presenting with severe manifestations. The high burden populations are ethnic tribes living in the forested pockets of the states like Orissa, Jharkhand, Madhya Pradesh, Chhattisgarh and the North Eastern states which contribute bulk of morbidity and mortality due to malaria in the country. Drug resistance, insecticide resistance, lack of knowledge of actual disease burden along with new paradigms of malaria pose a challenge for malaria control in the country. Considering the existing gaps in reported and estimated morbidity and mortality, need for estimation of true burden of malaria has been stressed. Administrative, financial, technical and operational challenges faced by the national programme have been elucidated. Approaches and priorities that may be helpful in tackling serious issues confronting malaria programme have been outlined.     

Marine ecosystem regime shifts: challenges and opportunities for ecosystem-based management

Regime shifts have been observed in marine ecosystems around the globe. These phenomena can result in dramatic changes in the provision of ecosystem services to coastal communities. Accounting for regime shifts in management clearly requires integrative, ecosystem-based management (EBM) approaches. EBM has emerged as an accepted paradigm for ocean management worldwide, yet, despite the rapid and intense development of EBM theory, implementation has languished, and many implemented or proposed EBM schemes largely ignore the special characteristics of regime shifts. Here, we first explore key aspects of regime shifts that are of critical importance to EBM, and then suggest how regime shifts can be better incorporated into EBM using the concept of integrated ecosystem assessment (IEA). An IEA uses approaches that determine the likelihood that ecological or socio-economic properties of systems will move beyond or return to acceptable bounds as defined by resource managers and policy makers. We suggest an approach for implementing IEAs for cases of regime shifts where the objectives are either avoiding an undesired state or returning to a desired condition. We discuss the suitability and short-comings of methods summarizing the status of ecosystem components, screening and prioritizing potential risks, and evaluating alternative management strategies. IEAs are evolving as an EBM approach that can address regime shifts; however, advances in statistical, analytical and simulation modelling are needed before IEAs can robustly inform tactical management in systems characterized by regime shifts.     

Challenges and opportunities in proteomics data analysis

Accurate, consistent, and transparent data processing and analysis are integral and critical parts of proteomics workflows in general and for biomarker discovery in particular. Definition of common standards for data representation and analysis and the creation of data repositories are essential to compare, exchange, and share data within the community. Current issues in data processing, analysis, and validation are discussed together with opportunities for improving the process in the future and for defining alternative workflows.     

Challenges,achievements and opportunities in allelopathy research

Abstract

Allelopathy is defined as the suppression of any aspect of growth and/or development of one plant by another through the release of chemical compounds. Although allelopathic interference has been demonstrated many times using in vitro experiments, few studies have clearly demonstrated allelopathy in natural settings. This difficulty reflects the complexity in examining and demonstrating allelopathic interactions under field conditions. In this paper we address a number of issues related to the complexity of allelopathic interference in higher plants: These are: (i) is a demonstrated pattern or zone of inhibition important in documenting allelopathy? (ii) is it ecologically relevant to explain the allelopathic potential of a species based on a single bioactive chemical? (iii) what is the significance of the various modes of allelochemical release from the plant into the environment? (iv) do soil characteristics clearly influence allelopathic activity? (v) is it necessary to exclude other plant interference mechanisms?, and (vi) how can new achievements in allelopathy research aid in solving problems related to relevant ecological issues encountered in research conducted upon natural systems and agroecosystems? A greater knowledge of plant interactions in ecologically relevant environments, as well as the study of biochemical pathways, will enhance our understanding of the role of allelopathy in agricultural and natural settings. In addition, novel findings related to the relevant enzymes and genes involved in production of putative allelochemicals, allelochemical persistence in the rhizosphere, the molecular target sites of allelochemicals in sensitive plant species and the influence of allelochemicals upon other organisms will likely lead to enhanced utilization of natural products for pest management or as pharmaceuticals and nutraceuticals. This review will address these recent findings, as well as the major challenges which continue to influence the outcomes of allelopathy research.     

Challenges and opportunities of defining clinical leptin resistance

The widespread use of the inadequately defined term "leptin resistance" led the National Institutes of Health to convene a workshop aimed at developing a quantitative definition of this term that would facilitate mechanistic research into leptin's actions in human health and disease. Although leptin-responsive conditions are recognized, the field is limited by a lack of robust, easily quantifiable behavioral or metabolic biomarkers of the hormone's action. Further advances require biomarkers that can be used to identify patients who may benefit from leptin therapy and that are useful for understanding the determinants of clinical leptin responsiveness.     

Challenges and perspectives for species distribution modelling in the neotropics

The workshop 'Species distribution models: applications, challenges and perspectives' held at Belo Horizonte (Brazil), 29-30 August 2011, aimed to review the state-of-the-art in species distribution modelling (SDM) in the neotropical realm. It brought together researchers in ecology, evolution, biogeography and conservation, with different backgrounds and research interests. The application of SDM in the megadiverse neotropics-where data on species occurrences are scarce-presents several challenges, involving acknowledging the limitations imposed by data quality, including surveys as an integral part of SDM studies, and designing the analyses in accordance with the question investigated. Specific solutions were discussed, and a code of good practice in SDM studies and related field surveys was drafted.     

Challenges and opportunities for enhancing biotechnology and technology transfer in developing countries

Biotechnological innovation is gaining increased recognition as an important tool for improving global health. The challenge, however, lies in defining the role of technology transfer to develop therapies for diseases prevalent in developing countries. During the past decade, a large disparity emerged between the developed and developing world in accessing affordable medicines because of the pharmaceutical industry's focus on health areas bearing greatest profits. Discussed herein are several mechanisms that provide partial solutions to this challenge. The Office of Technology Transfer of the US National Institutes of Health has increased its technology licensing pertaining to neglected diseases to partners in developing regions. Establishing partnerships through the transfer of technologies and assisting indigenous institutions build R and D capacity may positively impact policies on protection of intellectual property rights and increase multinational company investments in lesser-developed countries. This will most probably result in the development of more accessible therapies for those in need.     

Dynamic energy budget approaches for modelling organismal ageing

Ageing is a complex multifactorial process involving a progressive physiological decline that, ultimately, leads to the death of an organism. It involves multiple changes in many components that play fundamental roles under healthy and pathological conditions. Simultaneously, every organism undergoes accumulative 'wear and tear' during its lifespan, which confounds the effects of the ageing process. The scenario is complicated even further by the presence of both age-dependent and age-independent competing causes of death. Various manipulations have been shown to interfere with the ageing process. Calorie restriction, for example, has been reported to increase the lifespan of a wide range of organisms, which suggests a strong relation between energy metabolism and ageing. Such a link is also supported within the main theories for ageing: the free radical hypothesis, for instance, links oxidative damage production directly to energy metabolism. The Dynamic Energy Budgets (DEB) theory, which characterizes the uptake and use of energy by living organisms, therefore constitutes a useful tool for gaining insight into the ageing process. Here we compare the existing DEB-based modelling approaches and, then, discuss how new biological evidence could be incorporated within a DEB framework.