Social Demand for Ecosystem Services and Implications for Watershed Management

We performed a sociocultural preference assessment for a suite of ecosystem services provided by the Kiamichi River watershed in the south‐central United States, a region with intense water conflict. The goal was to examine how a social assessment of services could be used to weigh tradeoffs among water resource uses for future watershed management and planning. We identified the ecosystem services beneficiaries groups, analyzed perception for maintaining services, assessed differences in the importance and perceived trends for ecosystem services, and explored the perceived impact on ecosystem services arising from different watershed management scenarios. Results show habitat for species and water regulation were two ecosystem services all beneficiaries agreed were important. The main discrepancies among stakeholder groups were found for water‐related services. The identification of potential tradeoffs between services under different flow scenarios promotes a dynamic management strategy for allocating water resources, one that mitigates potential conflicts. While it is widely accepted the needs of all beneficiaries should be considered for the successful incorporation of ecosystem services into watershed management, the number of studies actually using the sociocultural perspective in ecosystem service assessment is limited. Our study demonstrates it is both possible and useful to quantify social demand of ecosystem services in watershed management.     

Restoring Forests and Associated Ecosystem Services on Appalachian Coal Surface Mines

Surface coal mining in Appalachia has caused extensive replacement of forest with non-forested land cover, much of which is unmanaged and unproductive. Although forested ecosystems are valued by society for both marketable products and ecosystem services, forests have not been restored on most Appalachian mined lands because traditional reclamation practices, encouraged by regulatory policies, created conditions poorly suited for reforestation. Reclamation scientists have studied productive forests growing on older mine sites, established forest vegetation experimentally on recent mines, and identified mine reclamation practices that encourage forest vegetation re-establishment. Based on these findings, they developed a Forestry Reclamation Approach (FRA) that can be employed by coal mining firms to restore forest vegetation. Scientists and mine regulators, working collaboratively, have communicated the FRA to the coal industry and to regulatory enforcement personnel. Today, the FRA is used routinely by many coal mining firms, and thousands of mined hectares have been reclaimed to restore productive mine soils and planted with native forest trees. Reclamation of coal mines using the FRA is expected to restore these lands’ capabilities to provide forest-based ecosystem services, such as wood production, atmospheric carbon sequestration, wildlife habitat, watershed protection, and water quality protection to a greater extent than conventional reclamation practices.     

Fuzzy Modeling of Interactions Among Environmental Stressors in the Ecosystem of Lake Koronia,Greece

The development of a model for assessing the impact and interactions of stressors in the ecosystem of Lake Koronia, based on fuzzy inference, is presented in this paper. The proposed fuzzy inference model assesses the synergistic interactions among several significant stressors on fish production. These stressors include industrial pollution, pesticide and nutrient usage due to agricultural activities, and water level decrease due to irrigation works. Apart from the experts knowledge, expressed in a set of fuzzy rules, a number of parameters such as pH, conductivity, biochemical and chemical oxygen demand, and nitrate concentration were used as stressor indicators. The proposed model is capable of simulating the effect of a large variety of environmental conditions, and it can be used as a dynamic tool for ecosystem risk assessment since it produces both qualitative and quantitative results, allowing for comparisons of predictions with on-going observational research and ecosystem monitoring. Its operation was successfully verified for a number of different conditions, ranging from low stressor impact to high stressor impact (where, in fact, the fish production was diminished). Moreover, the proposed fuzzy inference model can be used as a tool for the investigation of the behavior of the aquatic ecosystem under a large number of hypothetical environmental risk scenarios.     

Assessment of Water Supply as an Ecosystem Service in a Rural-Urban Watershed in Southwestern Mexico City

Studies from the ecosystem services perspective can provide a useful framework because they allow us to fully examine the benefits that humans obtain from socio-ecological systems. Mexico City, the second largest city in the world, has faced severe problems related to water shortages, which have worsened due to increasing population. Demand for space has forced changes in land cover, including covering areas that are essential for groundwater recharge. The city has 880 km² of forest areas that are crucial for the water supply. The Magdalena River Watershed was chosen as a model because it is a well-preserved zone within Mexico City and it provides water for the population. The general aim of this study was to assess the ecosystem service of the water supply in the Magdalena River Watershed by determining its water balance (SWAT model) and the number of beneficiaries of the ecosystem services. The results showed that the watershed provides 18.4 hm³ of water per year. Baseflow was dominant, with a contribution of 85%, while surface runoff only accounted for 15%. The zone provides drinking water to 78,476 inhabitants and could supply 153,203 potential beneficiaries. This work provides an example for understanding how ecosystem processes determine the provision of ecosystem services and benefits to the population in a rural–urban watershed in Mexico City.     

Formulating an ecosystem approach to environmental protection

The U.S. Environmental Protection Agency (EPA) has embraced a new strategy of environmental protection that is place-driven rather than program-driven. This new approach focuses on the protection of entire ecosystems. To develop an effective strategy of ecosystem protection, however, EPA will need to: (1) determine how to define and delineate ecosystems and (2) categorize threats to individual ecosystems and priority rank ecosystems at risk. Current definitions of ecosystem in use at EPA are inadequate for meaningful use in a management or regulatory context. A landscape-based definition that describes an ecosystem as a volumetric unit delineated by climatic and landscape features is suggested. Following this definition, ecosystems are organized hierarchically, from megaecosystems, which exist on a continental scale (e.g., Great Lakes), to small local ecosystems.Threats to ecosystems can generally be categorized as: (1) ecosystem degradation (occurs mainly through pollution) (2) ecosystem alteration (physical changes such as water diversion), and (3) ecosystem removal (e.g., conversion of wetlands or forest to urban or agricultural lands). Level of threat (i.e., how imminent), and distance from desired future condition are also important in evaluating threats to ecosystems. Category of threat, level of threat, and distance from desired future condition can be combined into a three-dimensional ranking system for ecosystems at risk. The purpose of the proposed ranking system is to suggest a preliminary framework for agencies such as EPA to prioritize responses to ecosystems at risk.     

The reversible process concept applied to the environmental management of large river systems

The wetland ecosystems occurring within alluvial floodplains change rapidly. Within the ecological successions, the life span of pioneer and transient stages may be measured in several years or decades depending on the respective influences of allogenic (water dynamics, erosion, and deposition) and autogenic developmental processes (population dynamics, eutrophication, and terrestrialization). This article emphasizes the mechanisms that are responsible for the ecosystem changes and their importance to environmental management. Two case studies exemplify reversible and irreversible successional processes in reference to different spatial and temporal scales. On the scale of the former channels, the standing-water ecosystems with low homeostasis may recover their previous status after human action on the allogenic processes. On the scale of a whole reach of the floodplain, erosion and deposition appear as reversible processes that regenerate the ecological successions. The concepts of stability and reversibility are discussed in relation to different spatiotemporal referential frameworks and different levels of integration. The reversible process concept is also considered with reference to the energy inputs into the involved subsystems. To estimate the probability of ecosystem regeneration or the cost of restoration, a concept of degrees of reversibility is proposed.     

Influence of Bioenergy Crop Production and Climate Change on Ecosystem Services

Land use change can significantly affect the provision of ecosystem services and the effects could be exacerbated by projected climate change. We quantify ecosystem services of bioenergy‐based land use change and estimate the potential changes of ecosystem services due to climate change projections. We considered 17 bioenergy‐based scenarios with Miscanthus, switchgrass, and corn stover as candidate bioenergy feedstock. Soil and Water Assessment Tool simulations of biomass/grain yield, hydrology, and water quality were used to quantify ecosystem services freshwater provision (FWPI), food (FPI) and fuel provision, erosion regulation (ERI), and flood regulation (FRI). Nine climate projections from Coupled Model Intercomparison Project phase‐3 were used to quantify the potential climate change variability. Overall, ecosystem services of heavily row cropped Wildcat Creek watershed were lower than St. Joseph River watershed which had more forested and perennial pasture lands. The provision of ecosystem services for both study watersheds were improved with bioenergy production scenarios. Miscanthus in marginal lands of Wildcat Creek (9% of total area) increased FWPI by 27% and ERI by 14% and decreased FPI by 12% from the baseline. For St. Joseph watershed, Miscanthus in marginal lands (18% of total area) improved FWPI by 87% and ERI by 23% while decreasing FPI by 46%. The relative impacts of land use change were considerably larger than climate change impacts in this paper. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

Forest Health,Collective Behaviors,and Management

This study compares community-based managed forests under different purposes of management, namely, state-driven conservation or community-designed utilization in two villages located in the Sopsai watershed, Nan Province, northern Thailand. The forest health under different intensity of uses is assessed in association with the collective behaviors and long-term purposes embedded in village social–cultural context. The study found no significant differences in forest succession and proportion in diameter at 1.3 m (dbh) class and height-class distribution of the forest under different use intensity. The forest for utilization also showed higher density and basal area of the local preferred species than the conservation forest. In the utilization forest, we also found a higher number of multipurpose and preferred species than in the conservation forest, which actually responded to the needs of the community in the long term to have more wood products (both firewood and timbers). The community-based forest management (CBFM) for utilization can also lead to natural regeneration and biodiversity similar to conservation forests. Through CBFM, forest resources can be managed to maintain the healthy condition under different intensities and respond to both community needs and external expectation. The findings also emphasize the importance of recognizing community needs and management objectives in watershed restoration and improving the productivity of forests under collective management.     

Riparian vegetation and channel morphology impact on spatial patterns of water quality in agricultural watersheds

A model based on theKLS factors of the Universal Soil Loss Equation (USLE) accurately predicted temporal dynamics and relative peak levels of suspended solids, turbidity, and phosphorus in an agricultural watershed with well-protected streambanks and cultivation to the stream edge. Fine suspended solids derived from surface runoff appeared to be a major component of the suspended solids in this stream. The model did not predict the same parameters in a watershed with unstable channel substrates, exposed streambanks, and heterogeneity in riparian vegetation and channel morphology. The rate of increase in concentration of the water quality parameters was higher than predicted in areas without riparian vegetation and with unstable substrates. Peak levels were higher than predicted where unstable channel substrates occurred, and potential energy of the stream was high because of stream alterations (removal of near-stream vegetation and creation of a uniform, straight channel). Timing of the peak levels of suspended solids, turbidity, and phosphorus in these areas seemed related to major flushes of discharge due to delayed inputs from the surface or subsurface or both or to rapid urban drainage. Higher suspended solids concentration in this stream seemed to involve larger quantities of large particles. Thus, the USLE may not adequately predict relative water quality conditions within a watershed when variation in channel morphology and riparian vegetation exists. We make the following recommendations:

1. Models to predict water quality effects of management programs should combine a terrestrial phase (which details hydrologic and erosion processes associated with surface runoff) with an aquatic phase (which details hydrologic processes of scour and sediment transport in channels). The impact of near-channel areas on these hydrologic processes should receive special attention.
2. Sampling schemes should be designed to account for the impact on water quality of both watershed land surface and inand near-channel processes. In order to help distinguish sources of suspended solids, researchers should emphasize analysis of size distribution of particles transported.
3. Best management systems for improving the broadest range of water resources in agricultural watersheds need to be based on an expanded “critical area” approach, which includes identification of critical erosive and depositional areas in both terrestrial and aquatic environments.

     

RIPARIAN ZONE CLASSIFICATION FOR MANAGEMENT OF STREAM WATER QUALITY AND ECOSYSTEM HEALTH1

ABSTRACT: Riparian zones perform a variety of biophysical functions that can be managed to reduce the effects of land use on instream habitat and water quality. However, the functions and human uses of riparian zones vary with biophysical factors such as landform, vegetation, and position along the stream continuum. These variations mean that “one size fits all” approaches to riparian management can be ineffective for reducing land use impacts. Thus riparian management planning at the watershed scale requires a framework that can consider spatial differences in riparian functions and human uses We describe a pilot riparian zone classification developed to provide such a framework for riparian management in two diverse river systems in the Waikato region of New Zealand. Ten classes of riparian zones were identified that differed sufficiently in their biophysical features to require different management. Generic “first steps” and “best practical” riparian management recommendations and associated costs were developed for each riparian class. The classification aims to not only improve our understanding of the effectiveness of riparian zone management as a watershed management tool among water managers and land owners, but to also provide a basis for deciding on management actions.     

Naturalness In Biological Conservation

Conservation scientists are arguing whether naturalness provides a reasonable imperative for conservation. To clarify this debate and the interpretation of the term natural, I analyze three management strategies – ecosystem preservation, ecosystem restoration, and ecosystem engineering – with respect to the naturalness of their outcomes. This analysis consists in two parts. First, the ambiguous term natural is defined in a variety of ways, including (1) naturalness as that which is part of nature, (2) naturalness as a contrast to artifactuality, (3) naturalness as an historical independence from human actions, and (4) naturalness as possession of certain properties. After that, I analyze the different conceptions with respect to their implications for the three management strategies. The main conclusion is that there exists no single conception of naturalness that could distinguish between the outcomes of the three management methods. Therefore, as long as the outcomes of the different methods are regarded as being of a different value in conservation, we should either abandon the idea of naturalness as the guiding concept in conservation or use the term natural only in the ways that take both its historical and feature dependent meanings into consideration.     

Mapping Ecological Processes and Ecosystem Services for Prioritizing Restoration Efforts in a Semi-arid Mediterranean River Basin

Semi-arid Mediterranean regions are highly susceptible to desertification processes which can reduce the benefits that people obtain from healthy ecosystems and thus threaten human wellbeing. The European Union Biodiversity Strategy to 2020 recognizes the need to incorporate ecosystem services into land-use management, conservation, and restoration actions. The inclusion of ecosystem services into restoration actions and plans is an emerging area of research, and there are few documented approaches and guidelines on how to undertake such an exercise. This paper responds to this need, and we demonstrate an approach for identifying both key ecosystem services provisioning areas and the spatial relationship between ecological processes and services. A degraded semi-arid Mediterranean river basin in north east Spain was used as a case study area. We show that the quantification and mapping of services are the first step required for both optimizing and targeting of specific local areas for restoration. Additionally, we provide guidelines for restoration planning at a watershed scale; establishing priorities for improving the delivery of ecosystem services at this scale; and prioritizing the sub-watersheds for restoration based on their potential for delivering a combination of key ecosystem services for the entire basin.     

LANDSCAPE ATTRIBUTES AS CONTROLS ON GROITHD WATER NITRATE REMOVAL CAPACITY OF RIPARIAN ZONES1

ABSTRACT: Inherent site factors can generate substantial variation in the ground water nitrate removal capacity of riparian zones. This paper examines research in the glaciated Northeast to relate variability in ground water nitrate removal to site attributes depicted in readily available spatial databases, such as SSUIRGO. Linking site‐specific studies of riparian ground water nitrate removal to spatial data can help target high‐value riparian locations for restoration or protection and improve the modeling of watershed nitrogen flux. Site attributes, such as hydric soil status (soil wetness) and geomorphology, affect the interaction of nitrate‐enriched ground water with portions of the soil ecosystem possessing elevated biogeochemical transformation rates (i.e., biologically active zones). At our riparian sites, high ground water nitrate‐N removal rates were restricted to hydric soils. Geomorphology provided insights into ground water flowpaths. Riparian sites located on outwash and organic/alluvial deposits have high potential for nitrate‐enriched ground water to interact with biologically active zones. In till deposits, ground water nitrate removal capacity may be limited by the high occurrence of surface seeps that markedly reduce the time available for biological transformations to occur within the riparian zone. To fully realize the value of riparian zones for nitrate retention, landscape controls of riparian nitrate removal in different climatic and physiographic regions must be determined and translated into available spatial databases.     

Observed Winter Warming of the Chesapeake Bay Estuary (1949–2002): Implications for Ecosystem Management

A large number of studies have documented 20th century climate variability and change at the global, hemispheric, and regional levels. However, understanding the implications of climate change for environmental management necessitates information at the level of the ecosystem. Historical monitoring data from the Chesapeake Bay estuary were used to identify temporal patterns of estuarine temperature anomalies in the surface (1 m) and subsurface (15 m) between 1949 and 2002. Data indicated a trend in surface and subsurface warming of +0.16°C and +0.21°C per decade, respectively, driven by warming during winter and spring. These trends suggest warming of the estuary since the mid-20th century of approximately 0.8–1.1°C. Estuarine temperatures correlated well with other independent data records for sea surface and surface air temperatures in the region and to a lesser extent, the northern hemisphere. Gross long-term temperature variability in the estuary was consistent with North Atlantic climate variability associated with the prolonged positive North Atlantic Oscillation/Arctic Oscillation and increased anthropogenic radiative forcing, although localized environmental drivers likely are important as well. A simple spatial analysis revealed strong seasonal latitudinal and longitudinal gradients in estuarine temperature as well as a north–south gradient in long-term temperature trends. Continued warming of the estuary will have important implications for ecosystem structure and function as well as attempts to manage existing challenges such as eutrophication and benthic hypoxia. However, such management efforts must be cognizant of the effects of various climate and nonclimate drivers of environmental variability and change operating over different spatial and temporal scales.Published online     

Phreatophytic Vegetation and Groundwater Fluctuations: A Review of Current Research and Application of Ecosystem Response Modeling with an Emphasis on Great Basin Vegetation

Although changes in depth to groundwater occur naturally, anthropogenic alterations may exacerbate these fluctuations and, thus, affect vegetation reliant on groundwater. These effects include changes in physiology, structure, and community dynamics, particularly in arid regions where groundwater can be an important water source for many plants. To properly manage ecosystems subject to changes in depth to groundwater, plant responses to both rising and falling groundwater tables must be understood. However, most research has focused exclusively on riparian ecosystems, ignoring regions where groundwater is available to a wider range of species. Here, we review responses of riparian and other species to changes in groundwater levels in arid environments. Although decreasing water tables often result in plant water stress and reduced live biomass, the converse is not necessarily true for rising water tables. Initially, rising water tables kill flooded roots because most species cannot tolerate the associated low oxygen levels. Thus, flooded plants can also experience water stress. Ultimately, individual species responses to either scenario depend on drought and flooding tolerance and the change in root system size and water uptake capacity. However, additional environmental and biological factors can play important roles in the severity of vegetation response to altered groundwater tables. Using the reviewed information, we created two conceptual models to highlight vegetation dynamics in areas with groundwater fluctuations. These models use flow charts to identify key vegetation and ecosystem properties and their responses to changes in groundwater tables to predict community responses. We then incorporated key concepts from these models into EDYS, a comprehensive ecosystem model, to highlight the potential complexity of predicting community change under different fluctuating groundwater scenarios. Such models provide a valuable tool for managing vegetation and groundwater use in areas where groundwater is important to both plants and humans, particularly in the context of climate change.     

Watershed Evapotranspiration Increased due to Changes in Vegetation Composition and Structure Under a Subtropical Climate1

Abstract: Natural forests in southern China have been severely logged due to high human demand for timber, food, and fuels during the past century, but are recovering in the past decade. The objective of this study was to investigate how vegetation cover changes in composition and structure affected the water budgets of a 9.6‐km² Dakeng watershed located in a humid subtropical mountainous region in southern China. We analyzed 27 years (i.e., 1967‐1993) of streamflow and climate data and associated vegetation cover change in the watershed. Land use/land cover census and Normalized Difference of Vegetation Index (NDVI) data derived from remote sensing were used to construct historic land cover change patterns. We found that over the period of record, annual streamflow (Q) and runoff/precipitation ratio did not change significantly, nor did the climatic variables, including air temperature, Hamon’s potential evapotranspiration (ET), pan evaporation, sunshine hours, and radiation. However, annual ET estimated as the differences between P and Q showed a statistically significant increasing trend. Overall, the NDVI of the watershed had a significant increasing trend in the peak spring growing season. This study concluded that watershed ecosystem ET increased as the vegetation cover shifted from low stock forests to shrub and grasslands that had higher ET rates. A conceptual model was developed for the study watershed to describe the vegetation cover‐streamflow relationships during a 50‐year time frame. This paper highlighted the importance of eco‐physiologically based studies in understanding transitory, nonstationary effects of deforestation or forestation on watershed water balances.     

Quantifying Terrestrial Ecosystem Carbon Dynamics in the Jinsha Watershed, Upper Yangtze, China from 1975 to 2000

Quantifying the spatial and temporal dynamics of carbon stocks in terrestrial ecosystems and carbon fluxes between the terrestrial biosphere and the atmosphere is critical to our understanding of regional patterns of carbon budgets. Here we use the General Ensemble biogeochemical Modeling System to simulate the terrestrial ecosystem carbon dynamics in the Jinsha watershed of China’s upper Yangtze basin from 1975 to 2000, based on unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes. Our analysis demonstrates that the Jinsha watershed ecosystems acted as a carbon sink during the period of 1975–2000, with an average rate of 0.36 Mg/ha/yr, primarily resulting from regional climate variation and local land use and land cover change. Vegetation biomass accumulation accounted for 90.6% of the sink, while soil organic carbon loss before 1992 led to a lower net gain of carbon in the watershed, and after that soils became a small sink. Ecosystem carbon sink/source patterns showed a high degree of spatial heterogeneity. Carbon sinks were associated with forest areas without disturbances, whereas carbon sources were primarily caused by stand-replacing disturbances. It is critical to adequately represent the detailed fast-changing dynamics of land use activities in regional biogeochemical models to determine the spatial and temporal evolution of regional carbon sink/source patterns.     

UNDERSTANDING A WATERSHED FROM THE BIOLOGICAL VIEWPOINT1

In watershed management the effects of plants on water cannot be considered a constant and forgotten because: plants of different sizes and forms use water at different rates and plants of the same size differ in their needs for water because of anatomical differences. Many common denominators are present in all watersheds covered by vegetation. Forces exerted on the soil water by vegetation, climate and soil are the same kinds of forces. The differences between watersheds in water yield potential appear to be due to differences in the degree in which these forces are exerted. However, the influence of biotic factors are more individual. The similarities and differences existing between watersheds suggest some principles that can be used as guides to understanding individual watershed problems and as possible guides to determining when, how, and where to treat a given watershed. Eleven principles are given and their application to the definition and solution of biological or vegetational problems of watershed management are discussed.     

Impact of flood control reservoirs and pollution influx on the Sandy Creek Watershed,Mercer County,Pennsylvania, USA

A study of the impact of two flood control reservoirs and pollution influx was conducted on two streams within the Sandy Creek Watershed, Mercer County, Pennsylvania, USA. Fecal coliforms were significantly reduced in the outflows without affecting water chemistry, thereby improving the overall water quality. The size and composition of the aquatic communities as well as stream metabolism varied seasonably among the different sampling stations. Pollution influx primarily from communities and agricultural drainage had a greater impact on the stream ecosystem than did impounding of the streams. Natural wetlands and riparian vegetation were important factors in reducing the pollution load in these streams. The reestablishment and maintenance of riparian vegetation should therefore be an integral part of the land-use plan for watersheds in order to improve water quality and wildlife habitats. In the future, the maintenance of riparian vegetation should be given prime consideration in the development of watershed projects.     

根据土壤蓄水能力探讨若尔盖重要生态服务功能区的水源涵养功能

若尔盖水源涵养重要生态服务功能区是全国50个重要生态服务功能区域之一,具有极重要的水源涵养生态服务功能。该区涵盖四川省境内的黄河流域区,面积约1.6×104km2,区内分布有涵水能力极强的沼泽土和泥炭土,对调节黄河径流时空分布具有非常重要的作用。本文利用地理信息系统技术,用土壤饱和蓄水量指标评价了本区的水源涵养生态服务...