The Impact of Spatial Heterogeneity in Land Use Practices and Aquifer Characteristics on Groundwater Conservation Policy Cost

Estimation of agricultural policy cost for a given level of groundwater conservation requires the establishment of an accurate baseline condition. This is especially critical when the benefits and cost of any conservation program are generally estimated relative to the status quo policy or baseline situation. An inaccurate baseline estimate will lead to poor estimates of potential water conservation savings and agricultural policy cost. Over a 60-year planning horizon per acre net present value is as much as 29.8% higher for a study area when aquifer characteristics are assumed to be homogenous and set to their average area value than when the heterogeneity in aquifer characteristics is explicitly modeled.Aquifer Modeling, Economics, Resource /Energy Economics and Policy,

Habitat-Distribution Modeling of a Recolonizing Black Bear, Ursus americanus, Population in the Trans-Pecos Region of Texas

Black Bears (Ursus americanus) were once widespread across Texas, but their numbers were reduced in the early 1900s. Recolonization of the Trans-Pecos region of Texas has occurred via bears migrating northward from Mexico. Recent bear sightings have increased in this area. This could be an indication that the population in Texas is beginning to recover, but the population will continue to expand only if there is suitable habitat to occupy. To help identify suitable habitat and restoration areas, we developed a predictive habitat-distribution model by using records of Black Bear sightings from 1996 to 2003 to map the species' distribution. Using Bayesian statistics, we modeled the probability of occurrence of Black Bears in the Trans-Pecos region based on sighting locations. We used GIS layers for land use/landcover, elevation, water sources, and road networks to obtain covariates in our modeling. We used a 10-fold cross-validation to test the effectiveness of using sighting data. Our results indicated a negative association with bare areas, agriculture, and grassland landcovers. In addition, southern aspect, elevation, distance to water, slope, and western aspect also influenced suitable habitat. Both the original and validation datasets correctly classified bear sightings 93.9% and 93.7% of the time, respectively. Our model can be used to target restoration efforts to enhance the ability of the Black Bear to expand in the Trans-Pecos region. It can also identify private landowners most likely to be affected by the expansion of Black Bears for education and cooperative efforts

Use of Remote Sensing for Vegetation Inventories in a Desert Shrub Community

This item is part of the Arizona Land and People (formerly Progressive Agriculture in Arizona) archive. It was digitized from a physical copy provided by the College of Agriculture and Life Sciences at The University of Arizona. For more information about this periodical, please email CALS Publications at [email protected]

Changes in Cactus Numbers and Herbage Production After Chaining and Mesquite Control

This item is part of the Arizona Land and People (formerly Progressive Agriculture in Arizona) archive. It was digitized from a physical copy provided by the College of Agriculture and Life Sciences at The University of Arizona. For more information about this periodical, please email CALS Publications at [email protected]

Biosolids in a Chihuahuan Desert Ecosystem

The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Influence of Surface Biosolids Application on Infiltration

Biosolids from waste water treatment facilities applied to soils not only add plant nutrients, but also increase infiltration and decrease runoff and erosion. Wet biosolids from New York, NY, were surface applied at 0 to 90 Mg ha−1 dry weight to soils near El Paso, Tex. Simulated rainfall intensities of 16.4 cm hr−1 for 30 minutes applied to 0.5 m2 soil plots yielded initial infiltration rates of ~16 cm hr−1 for all plots. Biosolids applications extended the duration of the initially high infiltration rates. After 30 minutes, infiltration rates for bare soil were 3 cm hr−1 without and 10 cm hr−1 with 90 Mg biosolids ha−1. Applied biosolids, plant litter, surface gravel, and plant base contributed surface cover, which absorbed raindrop energy and reduced erosion. Biosolids increased cumulative infiltration on the vegetated, wet soils more than for the dry or bare soils. Biosolids increased cumulative infiltration from 2 to 6 cm on a bare gravelly soil and from 9.3 to 10.6 cm on a vegetated soil

The Impact of Spatial Heterogeneity in Land Use Practices and Aquifer Characteristics on Groundwater Conservation Policy Cost

Estimation of agricultural policy cost for a given level of groundwater conservation requires the establishment of an accurate baseline condition. This is especially critical when the benefits and cost of any conservation program are generally estimated relative to the status quo policy or baseline situation. An inaccurate baseline estimate will lead to poor estimates of potential water conservation savings and agricultural policy cost. Over a 60-year planning horizon per acre net present value is as much as 29.8% higher for a study area when aquifer characteristics are assumed to be homogenous and set to their average area value than when the heterogeneity in aquifer characteristics is explicitly modeled