Ecosystem Behavior Research Articles

Ongoing seasonally uneven climate warming leads to earlier autumn growth cessation in deciduous trees.

Ongoing global warming is causing phenological shifts that affect photosynthesis and growth rates in temperate woody species. However, the effects of seasonally uneven climate warming-as is occurring in much of Europe, where the winter/spring months are warming twice as fast than the summer/autumn months-on autumn growth cessation (completion of overwintering buds) and leaf senescence, and possible carry-over effects between phenophases, remain under-investigated. We conducted experiments in which we exposed saplings of canopy and understory species to 4°C warming in winter/spring, summer/autumn, or all year to disentangle how the timing of bud break, bud set completion, and leaf senescence is affected by seasonally uneven warming. All-year warming led to significantly delayed leaf senescence, but advanced bud set completion; summer/autumn warming only delayed leaf senescence; and winter/spring warming advanced both bud set and senescence. The non-parallel effects of warming on bud completion and leaf senescence show that leaf senescence alone is an inadequate proxy for autumn growth cessation in trees and counterintuitively suggest that continued uneven seasonal warming will advance cessation of primary growth in autumn, even when leaf senescence is delayed. Phenological responses to warming treatments (earlier spring onset, later autumn senescence) were more than twice as high in understory species than in canopy species, which can partly be explained by the absence of carry-over effects among phenophases in the former group. This underscores the need to consider differences among plant functional types when forecasting the future behaviour of ecosystems.

Enhanced global optimization methods applied to complex fisheries stock assessment models

Statistical fisheries models are frequently used by researchers and agencies to understand the behavior of marine ecosystems or to estimate the maximum acceptable catch of different species of commercial interest. The parameters of these models are usually adjusted through the use of optimization algorithms. Unfortunately, the choice of the best optimization method is far from trivial. This work proposes the use of population-based algorithms to improve the optimization process of the Globally applicable Area Disaggregated General Ecosystem Toolbox (Gadget), a flexible framework that allows the development of complex statistical marine ecosystem models. Specifically, parallel versions of the Differential Evolution (DE) and the Particle Swarm Optimization (PSO) methods are proposed. The proposals include an automatic selection of the internal parameters to reduce the complexity of their usage, and a restart mechanism to avoid local minima. The resulting optimization algorithms were called PMA (Parallel Multirestart Adaptive) DE and PMA PSO respectively. Experimental results prove that the new algorithms are faster and produce more accurate solutions than the other parallel optimization methods already included in Gadget. Although the new proposals have been evaluated on fisheries models, there is nothing specific to the tested models in them, and thus they can be also applied to other optimization problems. Moreover, the PMA scheme proposed can be seen as a template that can be easily applied to other population-based heuristics.

Assessment of the toxic effects of mixtures of three lanthanides (Ce, Gd, Lu) to aquatic biota

Lanthanide (LNs) release into the environment is expected to greatly increase in the coming years due to a high demand for new technologies. However there is a gap in the ecological risk assessment of these metals because most of the ecotoxicological studies have been performed with only one element, although they are usually found in nature as a group. This research evaluated the effects of mixtures of three lanthanides, cerium (Ce), gadolinium (Gd), and lutetium (Lu), representative of the light, middle and heavy rare earth elements, respectively, on seven aquatic species (A. fischeri, R. subcapitata, C. vulgaris, B. calyciflorus, H. incongruens, D. magna and D. rerio). Lanthanide content decreased over time in all toxicity test media and it was observed that LN sedimentation starts at the beginning of the tests with a steep decline of the available LN amount. Potential toxic effects of LNs were observed only in five species of the seven studied, predominantly in the unicellular organism (A. fischeri) and in the organisms belonging to the lower trophic levels (R. subcapitata and B. calyciflorus). The multi-toxicity approach performed in this study showed synergistic effects in tests performed with the bacteria A. fischeri and the algae R. subcapitata, and antagonistic effects for the rotifer B. calyciflorus. Although predicting the response of aquatic organisms exposed to multi-elements is not an easy task and can be masked by potential interactions with other compounds or even by nutrient removal. The variation in toxic action among species observed in this study reveals that lanthanide interaction in toxicity mechanisms should not be discarded, and supports that further studies with LN mixtures are required to properly understand their toxic behaviour in nature ecosystems.

PLANT’S-EYE VIEWS OF TAIPEI

The installation of “Plant’s-Eye Views of Taipei” is the result of an international workshop that took place in Taipei in summer 2018, organized as part of the 2018 Taipei Biennial. Under the direction of two participating artists, and with the help from ecologists and videographers, university students from the Asia-Pacific region each imagined themselves as a particular plant. Students began by examining the physiology of selected plants to better understand their characteristics and life histories, as well as their adaptive features and ecosystem behaviors. In viewing themselves as plants, students were able to see Taipei through a new lens as a place coproduced by the city’s urban flora and human communities. The installation including scaffolds, sketches, and films was exhibited at the Taipei Fine Arts Museum to explore different ways through which plants view the city, as well as notions of anthropomorphism, phytomorphism, and phototropism.

Consumption and performance responses of the amphipod Echinogammarus berilloni change during laboratory incubation

Microcosms try to mimic the behaviour of natural ecosystems; however, differences in experimental conditions reduce comparability among studies. A standard incubation duration may increase comparability between experiments without losing realism in the response. Some response variables can respond fast, acting as early warning signals of other, more important oncoming changes. In this experiment, we test the effects of resource quality and incubation duration on the performance of the amphipod Echinogammarus berilloni. Individuals were fed on five leaf species of contrasting quality and we measured their consumption rate, death rate, RNA:body mass (RNA:BM), growth rate, mass body condition and lipid body condition over time. We predicted that (i) resource quality would affect the response variables, (ii) consumption rate and RNA:BM ratio would act as early warning signals of oncoming changes in growth or death rates, and (iii) the inter-individual variation would gradually decrease with time. Resource quality was positively related to consumption rates, although it did not correlate to nutrient concentration and toughness of the materials. Amphipod body mass condition changed with diet, animals feeding on oak and beech showing the lowest values. Death rate, growth rate, RNA:BM, and lipid mass condition did not change with food resources. Consumption, growth rate and mass body condition changed with time. Moreover, consumption, mass body condition and RNA:BM significantly interacted with incubation duration. Variability among individuals in consumption and growth rate decreased with time, as predicted. Our results pointed that special care should be taken when comparing microcosm experiments with different incubation duration.

How Leadership Co-Creation Generates a Trickle-Down Effect on Employees' Resource Integration Behavior in Service Ecosystems: A Theoretical Framework

This article identifies service employees as key actors in service ecosystems who contribute to and steer the resource integration process to co-create value with other ecosystem actors. In an effort to address the research question how service employees can be supported in engaging in effective resource integration activities, a leadership co-creation trickle-down model is developed. It proposes that focal leaders who engage in collective leadership influence service employees’ resource integration behavior in service ecosystems by affecting their service co-creation role readiness.

A restoration ecology perspective on the treatment of inflammatory bowel disease.

The human gut can be considered an ecosystem comprised of a community of microbes and nonliving components such as food metabolites and food additives. Chronic diseases are increasingly associated with disruption of this ecosystem. The science of restoration ecology was developed to restore degraded ecosystems, but its principles have not been applied widely to gut medicine, including the treatment of inflammatory bowel disease (IBD). One principle of ecological restoration is that ‘passive’ restoration, which involves removing an ecosystem disturbance, should occur before attempting additional ‘active’ interventions. We discuss evidence that poor diet is principle source of disturbance in IBD, and therefore requires better attention in its research and clinical care. Another restoration principle is that higher biodiversity may improve ecosystem behavior, but this idea has not been tested for its possible importance in donor stool during fecal microbiota transplants. Lay summary: In patients with chronic disease the gut microbiome behaves like a disturbed ecosystem. Principles borrowed from the science of restoration ecology identify a need to better understand the influence of diet on treatment of inflammatory bowel disease and the importance of donor diversity in fecal microbiota transplants.

Groundwater characterization from an ecological and human perspective: an interdisciplinary approach in the Functional Urban Area of Parma, Italy

In the Parma Functional Urban Area, hydro-geo-ecology was investigated through an interdisciplinary approach, with emphasis on the shallow aquifer system. The study pointed out that domestic wells and fontanili are both fed by shallow groundwater affected by PCE and nitrate contamination, upgradient of the rural area located north of Parma City. Moreover, Folsomia candida tests suggested the possibility that other types of contaminants (not analysed in this study) can affect the shallow groundwater. Nowadays, PCE concentrations in the city centre are slightly higher than the limit set by law. Moreover, PCE aerobic biodegradation can be due to the local microbial community and then an effective natural attenuation can be expected along the groundwater flow pathway. These results suggest a very low risk for human health, linked to the groundwater consumption in the rural area north of Parma City. Conversely, no forecasts can be made at present about the possible impact of low PCE concentrations on the aquatic ecosystem observed at the fontanili. Concerning nitrate contamination, the higher concentrations detected in some wells and fontanili suggest a high risk for both human health and aquatic ecosystems. In a wider context, thanks to the interdisciplinary approach that combines successfully well-established investigation methods, the present study allows a better knowledge of the hydro-geo-ecological behaviour of groundwater-dependent ecosystems. At the same time, through purpose-designed experimental investigations and simulation models, this approach could be used as a sort of guideline useful in studying such complex environmental systems.

Response of sediment organic phosphorus composition to lake trophic status in China

Organic phosphorus (Po) constitutes the most important fraction of P in lake sediments, and the compositional properties of Po affect its behavior in lake ecosystems. In this study, 31P NMR, FT-IR spectroscopy, and UV–visible absorbance spectroscopy were combined to identify the dynamic composition of sediment Po across two sets of lakes in China ranging from oligotrophic to eutrophic, and their possible effects on lake eutrophication were evaluated. The results showed that sediment Po content (accounting for 24–75% of TP) was positively correlated with trophic status in both Eastern Plain and Yun-Gui Plateau lakes of China, and the linear relationship was more stable compared to total P (TP), implying that sediment Po may be a superior indicator of trophic status than TP. The Po component, phosphonate accounted for only 0.4% or less of Po, while the monoester P and diester P, accounted for 2–24% and 0.5–5% of Po, respectively, and were the main factors causing Po to increase with the increasing trophic status. The factors were closely related to the enhanced organic sewage load and intensification of contemporary sedimentation of phytoplankton. As trophic status increased, sediment Po might integrate into larger amounts of aromatic substances and functional groups, which could enhance the stability of Po in sediments. Furthermore, sediments from lakes with higher trophic status exhibited a higher degree of humification and molecular weights, which impart resistance to biodegradation, and therefore, reduced the risk of sediment Po release. However, the massive accumulation of bioavailable Po (monoester and diester P) allows possible degradation, supporting algal growth and maintains eutrophic status because there is abundant alkaline phosphatase in eutrophic lakes. Thus, to control lake eutrophication more effectively, targeted actions are urgently required to reduce the accumulation and degradation of Po in lake sediment.

Global hydro-climatic biomes identified via multitask learning

Abstract. The most widely used global land cover and climate classifications are based on vegetation characteristics and/or climatic conditions derived from observational data. However, these classification schemes do not directly stem from the characteristic interaction between the local climate and the biotic environment. In this work, we model the dynamic interplay between vegetation and local climate in order to delineate ecoregions that share a coherent response to hydro-climate variability. Our novel framework is based on a multitask learning approach that discovers the spatial relationships among different locations by learning a low-dimensional representation of predictive structures. This low-dimensional representation is combined with a clustering algorithm that yields a classification of biomes with coherent behaviour. Experimental results using global observation-based datasets indicate that, without the need to prescribe any land cover information, the identified regions of coherent climate–vegetation interactions agree well with the expectations derived from traditional global land cover maps. The resulting global hydro-climatic biomes can be used to analyse the anomalous behaviour of specific ecosystems in response to climate extremes and to benchmark climate–vegetation interactions in Earth system models.

Climate Change Effects on Secondary Compounds of Forest Trees in the Northern Hemisphere.

Plant secondary compounds (PSCs), also called secondary metabolites, have high chemical and structural diversity and appear as non-volatile or volatile compounds. These compounds may have evolved to have specific physiological and ecological functions in the adaptation of plants to their growth environment. PSCs are produced by several metabolic pathways and many PSCs are specific for a few plant genera or families. In forest ecosystems, full-grown trees constitute the majority of plant biomass and are thus capable of producing significant amounts of PSCs. We summarize older literature and review recent progress in understanding the effects of abiotic and biotic factors on PSC production of forest trees and PSC behavior in forest ecosystems. The roles of different PSCs under stress and their important role in protecting plants against abiotic and biotic factors are also discussed. There was strong evidence that major climate change factors, CO2 and warming, have contradictory effects on the main PSC groups. CO2 increases phenolic compounds in foliage, but limits terpenoids in foliage and emissions. Warming decreases phenolic compounds in foliage but increases terpenoids in foliage and emissions. Other abiotic stresses have more variable effects. PSCs may help trees to adapt to a changing climate and to pressure from current and invasive pests and pathogens. Indirect adaptation comes via the effects of PSCs on soil chemistry and nutrient cycling, the formation of cloud condensation nuclei from tree volatiles and by CO2 sequestration into PSCs in the wood of living and dead forest trees.

A BLUEPRINT FOR ELEMENTARY REPRESENTATIVE WATERSHED SPECIFICATION

Provision of ecosystem services is necessary for our quality of life. In this vein, itis critical to develop a baseline to monitor the ecosystem behavior usingmonitoring, mapping, and modeling indicators of landscape condition. Therepresentative watersheds (RWs) can therefore be considered as such decisionblueprint to implement the best management practices to conserve andconsequently improve ecosystem services. There are few researches for theselection of RWs. However, the comprehensive and of course applicablemethodologies still are lacked particularly in developing countries whereconcentration and proper directing of conservation measures are further neededowing to investments constraints. Therefore, in the present study, an intensivewatershed selection process was undertaken to identify RW across the Gharesoo-Gorgan River Basin (ca. 12987 km2), Golestan Province, Iran. This study aimed toadopt the Laize’s approach in Gharesoo-Gorgan Watershed for identifying therepresentative sub-watershed. Towards this, four GIS-based layers of elevation,slope, rainfall erosivity and land use were selected for sub-watershedscharacterization. The representative watershed index (RWI) was then calculatedand mapped using MATLAB 2016 and ArcGIS 10.3 softwares, respectively. TheRWI was calculated pixel wise for all nine individual sub-watersheds and the entirewatershed as reference area with the help of matrix combinations of four studylayers. Ultimately, RWIs obtained from 21.3 to 62.6 with mean of 44.94±14.49 andcoefficient of variation of 32.25% were used for sub-watershed prioritization.Accordingly, the sub-watershed 8 in north east with RWI of 56.8 was proposed asthe final RW for the whole Gharesoo-Gorgan Watershed. The results of the study ishelpful to be used by authorities for launching monitoring systems in the RW tocollect behavioral indicators leading to designation of reasonable ecoenvironmentalrestoration strategies.

Biophysical effects on soil crack morphology in a faunally active dryland vertisol

Faunal behavior in dryland ecosystems may physically influence swelling soil hydrologic and pedologic processes due to its contributions to soil crack formation. In order to provide a physical link between this faunal activity and pedological processes, we use a resin visualization technique and X-ray imaging to characterize the biomechanical influences of biocompaction (mega/meso-herbivores) and bioturbation (termites) on 3D crack morphology and topology in a faunally active dryland vertisol system. Results show increased soil cracking intensity due to faunal influence. However, this increased cracking diverged by faunal influence: bioturbation creates “surficial” (shallow, extensive) crack networks while biocompaction creates “systematic” (deep, narrow) crack networks, compared to a reference soil. Biocompacted soils also exhibit a memory of past wetting and drying events via vertically layered crack morphologies. Despite differences in these crack magnitudes between the faunal influences, crack structures show morphological and topological similarity as a topological network. These persistent differences in field crack systems may potentially create convectively-driven “hotspots” of enhanced water and carbon gas transport in dryland ecosystems as a result of crack formation, highlighting the importance of considering fracture behavior in both an ecological, atmospheric, and pedologic context.

How well do meteorological drought indices predict live fuel moisture content (LFMC)? An assessment for wildfire research and operations in Mediterranean ecosystems

Live Fuel Moisture Content (LFMC) is a critical variable affecting fire ignition, behavior and severity in many ecosystems. Although the use of meteorological drought indices as proxies for LFMC is a straightforward and widespread approach, it is largely unknown whether it can provide reliable estimates of LFMC, either for local or spatial applications. We address this issue by evaluating the capacity of drought indices to predict LFMC quantitative variations and critical values. LFMC observations used for reference were measured on six different Mediterranean shrub species for 15 years in 20 different sites in Southern France. Six drought indices were evaluated: the Duff Moisture Code (DMC) and Drought Code (DC) of the Canadian Forest Fire Weather Index System, the Keetch-Byram Drought Index (KBDI), the Nesterov Index (NI) and the Relative Water Content (RWC) of the soil derived from a forest water balance model for low (80 mm) and high (160 mm) field capacities. The species were classified in two groups according to their seasonal variability: high and low responding species. We found large differences in the capacity of drought indices to predict LFMC, with indices that simulate long-term drought dynamics (DC, RWC and KBDI) generally performing better than others (NI and DMC). Once calibrated at stand scale, drought indices showed a good potential for predicting LFMC of high responding species, although large variations between sites were observed. In contrast, spatial predictability was limited with a RMSE and R2 on the order of 20% and 0.3, respectively (for high responding species). Our results suggest that drought indices should therefore be used with caution for spatial applications in wildfire research and operational fire management. Because they can explicitly consider environmental (soil, climate) and biological (species traits related to dehydration) factors, mechanistic indices have a great potential to improve LFMC predictions.

The application of resilience concepts in palaeoecology

The concept of resilience has become increasingly important in ecological and socio-ecological literature. With its focus on the temporal behaviour of ecosystems, palaeoecology has an important role to play in developing a scientific understanding of ecological resilience. We provide a critical review of the ways in which resilience is being addressed by palaeoecologists. We review ~180 papers, identifying the definitions or conceptualisations of ‘resilience’ that they use, and analysing the ways in which palaeoecology is contributing to our understanding of ecological resilience. We identify three key areas for further development. First, the term ‘resilience’ is frequently defined too broadly to be meaningful without further qualification. In particular, palaeoecologists need to distinguish between ‘press’ vs ‘pulse’ disturbances, and ‘ecological’ vs ‘engineering’ resilience. Palaeoecologists are well placed to critically assess the extent to which these dichotomies apply in real (rather than theoretical) ecosystems, where climate and other environmental parameters are constantly changing. Second, defining a formal ‘response model’ – a statement of the anticipated relationships between proxies, disturbances and resilience properties – can help to clarify arguments, especially inferred causal links, since the difficulty of proving causation is a fundamental limitation of palaeoecology for understanding ecosystem drivers and responses. Third, there is a need for critical analysis of the role of scale in ecosystem resilience. Different palaeoenvironmental proxies are differently able to address the various temporal and spatial scales of ecological change, and these limitations, as well as methodological constraints on inherently noisy proxy data, need to be explored and addressed.

From theory to experimental design-Quantifying a trait-based theory of predator-prey dynamics.

Successfully applying theoretical models to natural communities and predicting ecosystem behavior under changing conditions is the backbone of predictive ecology. However, the experiments required to test these models are dictated by practical constraints, and models are often opportunistically validated against data for which they were never intended. Alternatively, we can inform and improve experimental design by an in-depth pre-experimental analysis of the model, generating experiments better targeted at testing the validity of a theory. Here, we describe this process for a specific experiment. Starting from food web ecological theory, we formulate a model and design an experiment to optimally test the validity of the theory, supplementing traditional design considerations with model analysis. The experiment itself will be run and described in a separate paper. The theory we test is that trophic population dynamics are dictated by species traits, and we study this in a community of terrestrial arthropods. We depart from the Allometric Trophic Network (ATN) model and hypothesize that including habitat use, in addition to body mass, is necessary to better model trophic interactions. We therefore formulate new terms which account for micro-habitat use as well as intra- and interspecific interference in the ATN model. We design an experiment and an effective sampling regime to test this model and the underlying assumptions about the traits dominating trophic interactions. We arrive at a detailed sampling protocol to maximize information content in the empirical data obtained from the experiment and, relying on theoretical analysis of the proposed model, explore potential shortcomings of our design. Consequently, since this is a “pre-experimental” exercise aimed at improving the links between hypothesis formulation, model construction, experimental design and data collection, we hasten to publish our findings before analyzing data from the actual experiment, thus setting the stage for strong inference.

Impact of Corn Earworm (Lepidoptera: Noctuidae) on Field Corn (Poales: Poaceae) Yield and Grain Quality.

Corn earworm, Helicoverpa zea (Boddie), commonly infests field corn, Zea mays (L.). The combination of corn plant biology, corn earworm behavior in corn ecosystems, and field corn value renders corn earworm management with foliar insecticides noneconomical. Corn technologies containing Bacillus thuringiensis (Bt) Berliner (Bacillales: Bacillaceae) were introduced that exhibit substantial efficacy against corn earworm and may reduce mycotoxin contamination in grain. The first generation Bt traits in field corn demonstrated limited activity on corn earworm feeding on grain. The pyramided corn technologies have greater cumulative protein concentrations and higher expression throughout the plant, so these corn traits should provide effective management of this pest. Additionally, reduced kernel injury may affect physical grain quality. Experiments were conducted during 2011-2012 to investigate corn earworm impact on field corn yield and grain quality. Treatments included field corn hybrids expressing the Herculex, YieldGard, and Genuity VT Triple Pro technologies. Supplemental insecticide treatments were applied every 1-2 d from silk emergence until silk senescence to create a range of injured kernels for each technology. No significant relationship between the number of corn earworm damaged kernels and yield was observed for any technology/hybrid. In these studies, corn earworm larvae did not cause enough damage to impact yield. Additionally, no consistent relationship between corn earworm damage and aflatoxin contamination was observed. Based on these data, the economic value of pyramided Bt corn traits to corn producers, in the southern United States, appears to be from management of other lepidopteran insect pests including European and southwestern corn borer.

From Petri Dishes to Model Ecosystems.

Model ecosystems could provide significant insight into the evolution and behavior of real ecosystems. We discuss the advantages and limitations of common approaches like mesocosms. In this context, we highlight recent breakthroughs that allow for the creation of networks of organisms with independently controlled environments and rates of chemical exchange.

Implications of tristability in pattern-forming ecosystems.

Many ecosystems show both self-organized spatial patterns and multistability of possible states. The combination of these two phenomena in different forms has a significant impact on the behavior of ecosystems in changing environments. One notable case is connected to tristability of two distinct uniform states together with patterned states, which has recently been found in model studies of dryland ecosystems. Using a simple model, we determine the extent of tristability in parameter space, explore its effects on the system dynamics, and consider its implications for state transitions or regime shifts. We analyze the bifurcation structure of model solutions that describe uniform states, periodic patterns, and hybrid states between the former two. We map out the parameter space where these states exist, and note how the different states interact with each other. We further focus on two special implications with ecological significance, breakdown of the snaking range and complex fronts. We find that the organization of the hybrid states within a homoclinic snaking structure breaks down as it meets a Maxwell point where simple fronts are stationary. We also discover a new series of complex fronts between the uniform states, each with its own velocity. We conclude with a brief discussion of the significance of these findings for the dynamics of regime shifts and their potential control.

The One Health Concept: 10 Years Old and a Long Road Ahead.

Over the past decade, a significant increase in the circulation of infectious agents was observed. With the spread and emergence of epizootics, zoonoses, and epidemics, the risks of pandemics became more and more critical. Human and animal health has also been threatened by antimicrobial resistance, environmental pollution, and the development of multifactorial and chronic diseases. This highlighted the increasing globalization of health risks and the importance of the human–animal–ecosystem interface in the evolution and emergence of pathogens. A better knowledge of causes and consequences of certain human activities, lifestyles, and behaviors in ecosystems is crucial for a rigorous interpretation of disease dynamics and to drive public policies. As a global good, health security must be understood on a global scale and from a global and crosscutting perspective, integrating human health, animal health, plant health, ecosystems health, and biodiversity. In this study, we discuss how crucial it is to consider ecological, evolutionary, and environmental sciences in understanding the emergence and re-emergence of infectious diseases and in facing the challenges of antimicrobial resistance. We also discuss the application of the “One Health” concept to non-communicable chronic diseases linked to exposure to multiple stresses, including toxic stress, and new lifestyles. Finally, we draw up a list of barriers that need removing and the ambitions that we must nurture for the effective application of the “One Health” concept. We conclude that the success of this One Health concept now requires breaking down the interdisciplinary barriers that still separate human and veterinary medicine from ecological, evolutionary, and environmental sciences. The development of integrative approaches should be promoted by linking the study of factors underlying stress responses to their consequences on ecosystem functioning and evolution. This knowledge is required for the development of novel control strategies inspired by environmental mechanisms leading to desired equilibrium and dynamics in healthy ecosystems and must provide in the near future a framework for more integrated operational initiatives.