William E. Fox

An Integrated Social, Economic, and Ecologic Conceptual (ISEEC) framework for considering rangeland sustainability

Currently, there is no standard method to assess the complex systems in rangeland ecosystems. Decision makers need baselines to create a common language of current rangeland conditions and standards for continued rangeland assessment. The Sustainable Rangeland Roundtable (SRR), a group of private and public organizations and agencies, has created a forum to discuss rangeland sustainability and assessment. The SRR has worked to integrate social, economic, and ecological disciplines related to rangelands and has identified a standard set of indicators that can be used to assess rangeland sustainability. As part of this process, SRR has developed a two-tiered conceptual framework from a systems perspective to study the validity of indicators and the relationships among them. The first tier categorizes rangeland characteristics into four states. The second tier defines processes affecting these states through time and space. The framework clearly shows that the processes affect and are affected by each other.

Pathogen prevalence and influence of composted dairy manure application on antimicrobial resistance profiles of commensal soil bacteria.

Composting manure, if done properly, should kill pathogenic bacteria such as Salmonella and Escherichia coli O157:H7, providing for an environmentally safe product. Over a 3-year period, samples of composted dairy manure, representing 11 composting operations (two to six samples per producer; 100 total samples), were screened for Salmonella and E. coli O157:H7 and were all culture negative. Nonpathogenic bacteria were cultured from these compost samples that could theoretically facilitate the spread of antimicrobial resistance from the dairy to compost application sites. Therefore, we collected soil samples (three samples per plot; 10 plots/treatment; 90 total samples) from rangeland that received either composted dairy manure (CP), commercial fertilizer (F), or no treatment (control, CON). Two collections were made appoximately 2 and 7 months following treatment application. Soil samples were cultured for Pseudomonas and Enterobacter and confirmed isolates subjected to antimicrobial susceptibility testing. Three species of Enterobacter (cloacae, 27 isolates; aeroginosa, two isolates; sakazakii, one isolate) and two species of Pseudomonas (aeruginosa, 11 isolates; putida, seven isolates) were identified. Five Enterobacter isolates were resistant to ampicillin and one isolate was resistant to spectinomycin. All Pseudomonas isolates were resistant to ampicillin, ceftiofur, florfenicol, sulphachloropyridazine, sulphadimethoxine, and trimethoprim/sulfamethoxazole and most isolates were resistant to chlortetracycline and spectinomycin. Pseudomonas isolates were resistant to an average of 8.6, 7.9, and 8 antibiotics for CON, CP, and F treatments, respectively. No treatment differences were observed in antimicrobial resistance patterns in any of the soil isolates examined. Results reported herein support the use of composted dairy manure as an environmentally friendly soil amendment.

Changing landowners, changing ecosystem? Land-ownership motivations as drivers of land management practices.

Motivations for owning rural land are shifting from an agricultural-production orientation to a preference for natural and cultural amenities. Resultant changes in land management have significant implications for the type and distribution of landscape-level disturbances that affect the delivery of ecosystem services. We examined the relationship between motivations for owning land and the implementation of conservation land management practices by landowners in the Southern Great Plains of the United States. Using a mail survey, we classified landowners into three groups: agricultural production, multiple-objective, and lifestyle-oriented. Cross tabulations of landowner group with past, current, and future use of 12 different land management practices (related to prescribed grazing, vegetation management, restoration, and water management) found that lifestyle-oriented landowners were overall less likely to adopt these practices. To the degree that the cultural landscape of rural lands transitions from production-oriented to lifestyle-oriented landowners, the ecological landscape and the associated flow of ecosystem services will likely change. This poses new challenges to natural resource managers regarding education, outreach, and policy; however, a better understanding about the net ecological consequences of lower rates of adoption of conservation management practices requires consideration of the ecological tradeoffs associated with the changing resource dependency of rural landowners.

MODELING THE EFFECTIVENESS OF CONSERVATION PRACTICES AT SHOAL CREEK WATERSHED, TEXAS, USING APEX

This study was conducted to evaluate the performance of the Agricultural Policy/Environmental eXtender (APEX) model using daily storm event runoff and sediment yields (1997-2005) collected at the outlet of the 22.5 km2 Shoal Creek watershed. This watershed only has intermittent streams. The watershed is within the U.S. Armys Fort Hood military reservation in central Texas. It received a combination of erosion control practices including implementation of gully plugs and contour soil ripping. APEX was calibrated and validated with a 183-subarea configuration delineated from a 5 m digital elevation model. Results from model calibration and validation confirmed that APEX was able to realistically estimate daily runoff and sediment yield for both the pre- and post-BMP conditions, as evidenced by R2 values ranging from 0.60 to 0.80 and Nash-Sutcliffe efficiency (EF) values ranging from 0.58 to 0.77 with an exception of 0.33. During the post-BMP period, the total sediment yield was significantly less than that from the pre-BMP period, even though the corresponding total precipitation amount from the post-BMP events (1025 mm) was more than that from the pre-BMP events (668 mm). The simulated sediment yield was summed up to 24.3 Mg ha-1 for the pre-BMP events and 7.6 Mg ha-1 for the post-BMP events, which were very close to the measured values of 24.9 and 8.1 Mg ha-1, respectively. The benefits of the existing BMPs were quantified as a reduction of 52% in runoff and 86% in sediment yield based on comparisons between predictions from the run using the pre-BMP model setup and measured values under BMP conditions. The results suggest that APEX is capable of simulating conservation practices on military landscapes, and that it a useful tool for scenario analysis to evaluate the effectiveness of conservation practices.

Public Perception of Desalinated Water from Oil and Gas Field Operations: Data from Texas

Data collected in two counties in north central Texas were used to empirically explore issues associated with public perception of desalinated water from oil and gas field operations. The data reveal that small percentages of respondents are extremely familiar with the process of desalination and extremely confident that desalinated water could meet human drinking water quality and purity standards. The data also indicate that respondents are more favorably disposed toward the use of desalinated water for purposes where the probability of human or animal ingestion is lessened. Lastly, the data show that respondents who are more familiar with desalination technology are more likely than those who are less familiar to believe that desalinated oil and gas field water could safely be used for selected purposes. Possible implications of these findings are advanced, as are suggestions for future research.

Framework for Comparing Ecosystem Impacts of Developing Unconventional Energy Resources on Western US Rangelands

Abstract More diverse sources of energy are needed for countries to progress toward energy independence and to meet future food production needs. The US Task Force on Strategic Unconventional Fuels concluded that to achieve this objective it is essential to develop a domestic unconventional fuels industry. Rangelands, which cover 50% to 70% of the earths terrestrial surface and dominate much of the western half of the United States, represent a major source of alternative energy resources. A framework to systematically identify biophysical-socioeconomic links that influence the delivery of ecosystem services affected by alternative uses of rangelands has been lacking. The Integrated Social, Economic, and Ecological Conceptual framework was developed by the Sustainable Rangeland Roundtable to address this deficiency. We apply this framework to demonstrate how the effect on ecosystem services of exploiting rangeland-based biofuel, natural gas, and wind energy resources can be systematically compared. We also demonstrate the use of this framework for selecting suitable indicators to monitor changes in the biophysical-socioeconomic links affected by the development of these unconventional energy sources. This type of approach can potentially enhance coordination between federal, state, and local agencies that are attempting to set polices and regulations for the sustainable development of unconventional energy resources on rangelands. Resumen Más diversidad de fuentes de energía es necesaria para que los países progresen hacia la independencia energética y cumplan con sus necesidades futuras de alimentación. El grupo estratégico para combustibles no-convencionales de los EUA concluyó que para lograr el éste objetivo, es esencial desarrollar una industria de combustibles no-convencionales interna. Los pastizales, quienes cubren entre el 50 al 70% de la superficie del planeta y dominan más de la mitad del oeste de EUA representan la mayor fuente de recursos de energía alternativa. Hace falta desarrollar un marco conceptual que sistemáticamente identifique los enlaces biofísicos-socioeconómicos que influyen en la entrega de los servicios de los ecosistemas que son afectados por los usos alternativos de los pastizales. El Marco Conceptual de Integración Social, Económica y Ecológica desarrollado por la Mesa de Sostenibilidad de los Pastizales está dirigido para atender esta deficiencia. Aplicamos este marco conceptual para demostrar como el efecto en los servicios del ecosistema por la explotación de biocombustibles basados en los pastizales, gas natural y fuentes de energía eólica pueden ser comparados sistemáticamente. También demostramos que el uso de este marco conceptual para seleccionar indicadores adecuados para monitorear cambios en los enlaces biofísicos-socioeconómicos afectados por el desarrollo de estas fuentes de energía no convencionales. Este tipo de punto de vista puede potencialmente enriquecer la coordinación entre las agencias federales, estatales y locales que están intentando establecer políticas y regulaciones en el desarrollo sostenible de fuentes de energía no convencional en pastizales.

Demographic Changes Drive Woody Plant Cover Trends—An Example from the Great Plains☆

ABSTRACT Woody plant encroachment—the conversion of grasslands to woodlands—continues to transform rangelands worldwide, yet its causes and consequences remain poorly understood. Despite this being a coupled human-ecological phenomenon, research to date has tended toward ecological aspects of the issue. In this paper, we provide new insight into the long-term relationships between human demographics and woody plant cover at the landscape scale. We used time-series aerial imagery and historical census data to quantify changes in population, land ownership patterns, and woody cover between 1937 and 2012 in three different settings in central Texas, USA. Woody cover closely paralleled population in a semi-urban watershed (R2 = 0.81) and two separate clusters of rural watersheds (R2 = 0.88 and 0.93), despite exhibiting very different directional trends over time in each setting. Woody cover also closely tracked average farm size in each rural watershed cluster (R2 = 0.57 and 0.90). These results highlight a tight coupling between demographic trends and the extent of woody plant cover. Such human factors may explain a great deal of woody plant cover patterns in other global rangeland systems with similar historical contexts and serve as a predictive proxy of landscape trends. Accordingly, policy recommendations should consider these demographic factors, and future woody plant encroachment research should explicitly include human dimensions.

Climate change effects on rangelands and rangeland management: affirming the need for monitoring

Abstract Uncertainty as to the extent and magnitude of changes in conditions that might occur due to climate change poses a problem for land and resource managers as they seek to adapt to changes and mitigate effects of climate variability. We illustrate using scenarios of projected future conditions on rangelands in the Northern Great Plains and Desert Southwest of the United States. These two regions are different in the ways climate change is projected to affect the regions. Projection of a longer and warmer growing season in the Northern Great Plains could lead to increased forage production and land productivity. Highly uncertain effects on summer monsoons that primarily control rangeland productivity in the Desert Southwest, combined with the possibility of more intense and/or frequent drought events, could present land managers with challenges stemming from decreased forage production and land productivity. Climate projections, though uncertain, provide land managers with basic insight into future conditions they might encounter. They need more. A focus on vulnerability and resilience, with explicit recognition of interactions between ecological and socio‐economic factors, coupled with systematic monitoring and assessment of observable conditions on the land to supplement information based on climate projections, will more effectively provide critical and specific information managers need to adaptively manage rangelands under uncertain climate futures.

Contour ripping is more beneficial than composted manure for restoring degraded rangelands in Central Texas

Rangelands in the United States that have been the site of military training exercises have suffered extensive ecological damage, largely because of soil compaction, creation of ruts, and damage to or destruction of vegetation--all of which lead to higher runoff and accelerated erosion. In this paper we report on a study carried out within the Fort Hood Military Reservation in Central Texas, where we evaluated the extent to which application of composted dairy manure and contour ripping affect soil infiltrability, amount of runoff, and nutrient concentrations in runoff. We conducted experiments at two locations, using rainfall simulation at one and monitoring discharge from small (0.3-ha) watersheds at the other. At the rainfall simulation site, we used six levels of compost application: 4, 8, 12, 16, 20, and 24 Mg/ha. We found that compost application had little effect on runoff, soil infiltration, sediment production, or nutrient concentrations in the runoff--except at the micro-watershed scale (12 and 24 Mg/ha); in this case, nutrient concentrations in runoff were initially high (for the rainfall simulations done immediately after compost application). In contrast, contour ripping--carried out 22 months after compost application on two of the micro-watersheds--was highly effective: runoff on the treated micro-watershed was reduced by half compared with the untreated micro-watershed. Our results suggest that (1) one-time applications of composted dairy manure do little to enhance infiltration of degraded rangelands over the short term (at the same time, these experiments demonstrated that compost application poses very little risk to water quality); and (2) for degraded rangelands with limited infiltration capacity, contour ripping is an effective strategy for increasing infiltration rates.

Land Degradation in Rangeland Ecosystems

Rangelands provide an array of ecosystem services such as food, fiber, water, recreation, minerals, and are important to the livelihoods of people across the globe, especially in developing countries. Competing land uses, overgrazing, extreme climate events, and socioeconomic changes are resulting in rangeland degradation in many parts of the world. Given our reliance on rangelands, degradation of this resource can have far-reaching effects. In this chapter, causes of rangeland degradation are examined. Indicators that can be used to identify degradation and methods for assessing the degree of degradation in rangeland ecosystems are discussed. Options and considerations for restoring disturbed rangeland are presented, in addition to future directions in rangeland degradation monitoring and assessment.