Mary V. Santelmann

Assessing alternative futures for agriculture in Iowa, U.S.A

The contributions of current agricultural practices to environmental degradation and the social problems facing agricultural regions are well known. However, landscape-scale alternatives to current trends have not been fully explored nor their potential impacts quantified. To address this research need, our interdisciplinary team designed three alternative future scenarios for two watersheds in Iowa, USA, and used spatially-explicit models to evaluate the potential consequences of changes in farmland management. This paper summarizes and integrates the results of this interdisciplinary research project into an assessment of the designed alternatives intended to improve our understanding of landscape ecology in agricultural ecosystems and to inform agricultural policy. Scenario futures were digitized into a Geographic Information System (GIS), visualized with maps and simulated images, and evaluated for multiple endpoints to assess impacts of land use change on water quality, social and economic goals, and native flora and fauna. The Biodiversity scenario, targeting restoration of indigenous biodiversity, ranked higher than the current landscape for all endpoints (biodiversity, water quality, farmer preference, and profitability). The Biodiversity scenario ranked higher than the Production scenario (which focused on profitable agricultural production) in all endpoints but profitability, for which the two scenarios scored similarly, and also ranked higher than the Water Quality scenario in all endpoints except water quality. The Water Quality scenario, which targeted improvement in water quality, ranked highest of all landscapes in potential water quality and higher than the current landscape and the Production scenario in all but profitability. Our results indicate that innovative agricultural practices targeting environmental improvements may be acceptable to farmers and could substantially reduce the environmental impacts of agriculture in this region.

Assessing the potential impacts of alternative landscape designs on amphibian population dynamics

An individual-based, spatially explicit population model was used to predict the consequences of future land-use alternatives for populations of four amphibian species in two central Iowa (midwest USA) agricultural watersheds. The model included both breeding and upland habitat and incorporated effects of climatic variation and demographic stochasticity. Data requirements of the model include life history characteristics, dispersal behavior, habitat affinities, as well as land use and landcover in geographic information systems databases. Future scenarios were ranked according to change in breeder abundance, saturation, and distribution, compared to baseline conditions. Sensitivity of simulation results to changes in model parameters was also examined. Simulated results suggest that while all four species modeled are likely to persist under present and future scenario conditions, two may be more at risk from future landscape change. Although the study species are all widespread generalists regarded as having a low conservation priority, they depend on wetlands and ponds, increasingly endangered habitats in agricultural landscapes. Broader conservation strategies in the region would ensure that these currently common organisms do not become the endangered species of the future.

The influence of airborne road dust on the chemistry of Sphagnum mosses

(1) Chemical analysis of Sphagnum moss samples collected from a raised Sphagnum bog along a transect at right angles to and away from a gravel road at Pointe Escuminac, New Brunswick, Canada, shows that concentrations of the elements Al, Cr, Fe, La, Ni, Sc, Sm and V are strongly correlated with one another, and their concentrations decrease logarithmically away from the road to a distance of 200 m. These elements are deposited primarily in wind-borne soil dust. Concentrations of Na and Cl are correlated; their primary source is precipitation enriched by sea spray. Amounts of As, Cd, Pb, and Zn are also intercorrelated and vary independently of other elements; their primary source is air pollution. (2) Enrichment factors (EF)-(element concentration: Al concentration in sample divided by the same ratio in the earths crust)-help to distinguish the primary sources of elements. Both the average enrichment factor and the degree of slope to the regression line of log(EF) vs. log[Al] indicate the degree to which the element is dependent on soil dust or some other factor as a primary source of atmospheric input to the bog, or is concentrated by the Sphagnum moss.

Applying Ecological Principles to Land-Use Decision Making in Agricultural Watersheds

The use of ecological principles and guidelines in land-use planning, as advocated by the Ecological Society of America Committee on Land Use (Dale et al., Chapter 1) will be critically important to achieving sustainable ecosystems in the next few decades as the world’s human population continues to grow and land area under human management increases. Definition of these principles and articulation of guidelines for use by planners and decision makers is an important first step, but there are many obstacles to the application of ecological guidelines in the land-use planning process. The use of alternative future scenarios can help overcome some of the difficulties associated with application of ecologically healthy land-use practices in agricultural watersheds. With the future scenario approach, abstract goals such as enhancing water quality and restoring biological diversity are translated into specific land-use practices (wetland restoration, riparian buffers, alternative cropping practices, preserves) expected to help achieve these goals. Maps and Geographic Information Systems (GIS) databases of the future alternatives become the spatial data used to evaluate the responses of the various modeled endpoints as well as the response of human perceptions of changes in land use. Alternative futures can be used to frame landscape ecological hypotheses (cf. Ahern 1999); models can then be employed to test those hypotheses and focus additional research on components that are poorly understood.

From the corn belt to the gulf : societal and environmental implications of alternative agricultural futures

Preface: Corn Belt Agricultural Landscape Values: Learning in the Field Introduction 1. Policy insights from alternative futures and integrated assessments Section 1: Environmental and societal drivers of agricultural landscape futures 2. Corn Belt Landscapes and Hypoxia of the Gulf of Mexico 3. Changing Societal Expectations for Environmental Benefits from Agricultural Policy Section 2: Assessing the Effects of Alternative Corn Belt Landscape Futures in Iowa 4. Alternative Scenarios for Future Iowa Agricultural Landscapes 5. Economic Implications 6. Farmers Perceptions 7. Water Quality 8. Plant Diversity 9. Pollinator Responses 10. Amphibian Population Dynamics 11. Impacts on Mammal Communities: A Spatially Explicit Model 12. Impacts on Mammal Communities: Landscape Indices 13. Wildlife Habitat Section 3: Policy Implications across Scales: From Iowa Watersheds to the Mississippi River Basin 14. An Integrated Assessment of Alternative Futures for Iowa Watersheds 15. Improving Water Quality from the Corn Belt to the Gulf 16. Agricultural Policy Choices

Agricultural water conservation in China: plastic mulch and traditional irrigation

Abstract Plastic mulch is commonly used with micro‐irrigation in developed countries; however, Chinese farmers use plastic mulch on a vast scale independent of micro‐irrigation. For the past three decades, Chinas land area in plastic mulch has exceeded the worlds total land area in micro‐irrigation. We report results from the water‐scarce region of Minqin County, where 87% of Chinese farmers interviewed responded that they use plastic mulch to conserve water and 53% to increase yields. Survey results indicated the desire to conserve water through the use of plastic mulch to be statistically equivalent to the desire to increase yields. Responses to interviews and surveys indicate that farmers perceive water savings of 24–26% when plastic mulch is used. Interview and survey responses suggest farming families are shifting to purchasing wheat from outside the region; a potential import of “virtual water” into this water‐scarce region.

Connecting Children to the Land: Place-Based Education in the Muddy Creek Watershed, Oregon

Abstract This article describes a project in which landowners and managers in a rural watershed near Corvallis, Oregon, taught local middle school children about their watershed through site visits and landowner interviews. The place-based curriculum gave students the opportunity to learn about local geography and farm and forest enterprises. Students reported a sense of accomplishment in the success of related class projects (planting rare native plants and designing a riparian buffer). Here are described project methods, successes, challenges, and learning outcomes, along with suggestions for improving the curriculum, with the idea that it might be fruitfully replicated in other geographic contexts.

Carbon dynamics in the hyporheic zone of a headwater mountain stream in the Cascade Mountains, Oregon

We investigated carbon dynamics in the hyporheic zone of a steep, forested, headwater catchment western Oregon, USA. Water samples were collected monthly from the stream and a well network during base flow periods. We examined the potential for mixing of different source waters to explain concentrations of DOC and DIC. We did not find convincing evidence that either inputs of deep groundwater or lateral inputs of shallow soil water influenced carbon dynamics. Rather, carbon dynamics appeared to be controlled by local processes in the hyporheic zone and overlying riparian soils. DOC concentrations were low in stream water (0.04–0.09 mM), and decreased with nominal travel time through the hyporheic zone (0.02–0.04 mM lost over 100 h). Conversely, stream water DIC concentrations were much greater than DOC (0.35–0.7 mM) and increased with nominal travel time through the hyporheic zone (0.2–0.4 mM gained over 100 h). DOC in stream water could only account for 10% of the observed increase in DIC. In situ metabolic processing of buried particulate organic matter as well as advection of CO2 from the vadose zone likely accounted for the remaining 90% of the increase in DIC. Overall, the hyporheic zone was a source of DIC to the stream. We suggest that, in mountain stream networks, hyporheic exchange facilitates the transformation of particulate organic carbon buried in floodplains and transports the DIC that is produced back to the stream where it can be evaded to the atmosphere.

Linking hydroclimate to fish phenology and habitat use with ichthyographs

Streamflow and water temperature (hydroclimate) influence the life histories of aquatic biota. The relationship between streamflow and temperature varies with climate, hydrogeomorphic setting, and season. Life histories of native fishes reflect, in part, their adaptation to regional hydroclimate (flow and water temperature), local habitats, and natural disturbance regimes, all of which may be affected by water management. Alterations to natural hydroclimates, such as those caused by river regulation or climate change, can modify the suitability and variety of in-stream habitat for fishes throughout the year. Here, we present the ichthyograph, a new empirically-based graphical tool to help visualize relationships between hydroclimate and fish phenology. Generally, this graphical tool can be used to display a variety of phenotypic traits. We used long-term data sets of daily fish passage to examine linkages between hydroclimate and the expression of life-history phenology by native fishes. The ichthyograph may be used to characterize the environmental phenology for fishes across multiple spatio-temporal domains. We illustrate the ichthyograph in two applications to visualize: 1) river use for the community of fishes at a specific location; and 2) stream conditions at multiple locations within the river network for one species at different life-history stages. The novel, yet simple, ichthyograph offers a flexible framework to enable transformations in thinking regarding relationships between hydroclimate and aquatic species across space and time. The potential broad application of this innovative tool promotes synergism between assessments of physical characteristics and the biological needs of aquatic species.

Vegetation Dynamics of Restored and Remnant Willamette Valley, OR Prairie Wetlands

Although once common throughout the Willamette Valley of Oregon, USA, prairie wetlands now occupy less than two percent of their historic extent. We compare vegetation trends and spatial patterns in plant community composition for prairie wetlands in the southern Willamette Valley, including four remnants and four restorations, sampled in 2000, 2005, and 2011. Patterns and trajectories of change in species assemblages were evaluated using non-metric multidimensional scaling (NMDS), multi-response permutation procedure (MRPP), native and introduced species diversity, and species accumulation curves. Geographic location was a statistically-significant grouping variable according to MRPP. Within each geographic region, vegetation at restorations has become more similar to that of remnants over time. Remnants have significantly higher native species richness than restorations and NMDS ordination of the data for native species separated remnants from restored sites. Species accumulation curves also revealed different patterns for native and introduced species in remnants compared to restorations. While the vegetation of restorations has become more similar to that of nearby remnants, remnants can still be distinguished from restorations based on the native species assemblages. These results show that, with sustained effort, plant communities in restorations can converge with those in remnant patches, and that it is important to preserve and restore sites in different geographic regions, as different locations may preserve different plant assemblages.