Normal Rainfall Years Research Articles

Estimating the Decant Rate from a Rehabilitated Opencast Colliery Using a Water Balance Approach

The long-term average decant rates from rehabilitated opencast collieries in South Africa are often estimated by assuming effective recharge rates through the spoils. However, large uncertainties are associated with these assumed recharge rates. Furthermore, this approach assumes that groundwater inflows and pit water outflows are negligible compared to the volumes of water recharged through the spoils. To obtain an estimate of the decant rate at a particular colliery, I used rainfall figures, pumping rates, and water elevations measured over a period of 6 months as well as estimated evaporation rates to construct a water balance. I then calculated a decant rate, independent of assumed recharge rates, that was significantly higher than a previous long-term estimate, despite the lower than average rainfall experienced during these 6 months. This discrepancy suggested that groundwater inflow was indeed contributing to the decant volumes. The decant rate during years of average rainfall was subsequently calculated by adding the estimated groundwater inflow to the recharge volumes found with the method based on assumed recharge. This decant rate was approximately 49 % greater than a previous estimate obtained by assuming negligible groundwater inflow. This study shows that the decant rates at rehabilitated opencast collieries could be significantly underestimated if the decants are assumed to be recharge-driven without considering the possibility of groundwater inflow. Underestimation of the decant rates will lead to flawed water management strategies, which could result in adverse environmental impacts.

Enhancing water and cropping productivity through Integrated System of Rice Intensification (ISRI) with aquaculture and horticulture under rainfed conditions

The System of Rice Intensification (SRI), based on modifications in the management practices for rice cultivation, is being utilized in many countries, although not without some controversy. One reason cited for non-adoption or disadoption of SRI is difficulties with water management under rainfed conditions with unreliable or aberrant rainfall distribution, which causes either flooding or long dry spells, or both. These constraints could be dealt with by tapping groundwater resources or by capture and use of rainwater runoff and/or by diversification of the farming system.A 2-year field experiment was conducted in Odisha, India to evaluate SRI under rainfed conditions and also to explore options for enhancing the economic productivity of land and water under such conditions. Four rice cropping systems were evaluated: (i) conventional rice cultivation under rainfed conditions, (ii) SRI methods as adapted to rainfed cultivation, (iii) rainfed SRI methods with drainage facilities and supplementary pump-irrigation, and (iv) integrated SRI (ISRI) where rainwater runoff was harvested and stored for aquaculture and horticulture crops while also providing supplementary irrigation for the rice crop.The rice crop grown with adapted SRI practices under rainfed condition showed significant improvements in the plants’ morphology and physiology. Phenotypic changes included: greater plant height and tillering, more number of leaves, and expanded root systems. These changes were accompanied by changes in plants’ physiological functions like greater xylem exudation rate and more light interception by the canopy, increased chlorophyll content in the leaves, and higher light utilization and photosynthetic rates during flowering. These factors were responsible for improved yield-contributing characteristics and for higher grain yield (52%) as compared with crops grown by conventional production methods. Comparing yield from rainfed conventional vs. SRI methods between drought and normal-rainfall years indicated that the latter methods are more drought-tolerant and productive; greatly expanded and active root systems with SRI have been important contributing factors.Introducing drainage and supplementary irrigation improved both the grain yield (by 29%) and water productivity for rainfed SRI. Further, integrating aquaculture and horticulture with SRI management and rainwater harvesting increased the rice yield further (by 8%) and the net water productivity. This integrated system was found to raise the net income per unit of water by more than 60-fold compared to conventional rainfed rice cultivation. This option looks promising for improving food security for smallholders under erratic or diminished rainfall conditions.

Agronomic and Economic Effect of Irrigation Rate in Cotton

Although the Southeast United States receives an average annual precipitation of 51.2 inches, cotton (Gossypium hirsutum L.) yield is often limited by erratic seasonal distributions. The objective of this research was to determine the effects of irrigation level on lint yield, net return over variable cost (NR), water use efficiency (WUE), water use efficiency to irrigation (WUEi), and returns to water use efficiency to irrigation (RWUEi) for cotton. Studies were conducted from 2001 to 2012 in Shellman, Georgia (84° 36′ W, 30° 44′ N) on a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults). Irrigation levels of 100, 66, 33%, and a non‐irrigated control were examined with the 100% level following the recommendations of Irrigator Pro for Cotton. The other water levels were applied at the same time and in proportion to the 100% level. The 100% irrigation level increased lint yield compared to non‐irrigated yield in 10 of the 12 years and increased NR eight of the 12 years. Water use efficiency, WUEi, and RWUEi responded differently across irrigation levels depending on precipitation grouping. The highest WUE and WUEi occurred in the 66% irrigation level during below average rainfall years at 57.06 and 92.68 lb ac−1 in−1, respectively. The highest RWUEi also occurred in the 66% rate during the below average rainfall years at $58.28 ac−1 in−1. The results showed that adequate irrigation resources are critical to cotton production over the long term and especially in years of moderate to less than average precipitation.

Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline

Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short-lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long-lived and large-bodied ectotherms, at opposite ends of a 250-m elevation-related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper-elevation, "Cima," and the lower-elevation, "Pumphouse," plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C-cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger-bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter-gradient variation in reproductive success across the rainfall cline. Land-use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem-level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts.

Impacts of agricultural water interventions on farm income: An example from the Kothapally watershed, India

Agricultural water interventions (AWI), e.g. in-situ soil and water conservation strategies, irrigation, and damming of rivers to increase groundwater recharge, have been suggested as important strategies to improve yields in tropical agriculture. Although the biophysical implications of AWIs have been well investigated, the coupling between the biophysical changes and the economic implications thereof is less well understood. In this study we translate the results from a hydrological model, SWAT, on crop yields for different cropping systems with and without agricultural water interventions, to hypothetical farm incomes for a watershed, Kothapally, located in Andhra Pradesh, India. It was found that on average, AWI significantly improved farm incomes by enabling the cultivation of a high value crop during the monsoon season (cotton), supplementary irrigated to bridge dry spells and replacing a traditional crop (sorghum), and also by enhancing the capacity to produce dry season, fully irrigated vegetable crops, in this case exemplified by onion. AWI combined with cotton resulted in more than a doubling of farm incomes compared to traditional sorghum-based systems without AWI during normal and wet years (i.e. for 75% of the years). Interestingly, we observed that the difference between the AWI system and the no intervention system was larger during years of high average rainfall compared to dry years. It was also found that access to irrigation was more important for farm income than crop choice and AWI per se, and thus farms with access irrigation benefitted more from AWI compared to farmers lacking access to irrigation. In conclusion, we suggest that in order to assess equity aspects in terms of farm income generation following the implementation of an AWI project, there is a need for income analyses at the farm level, since income estimates at the watershed level may mask important differences in economic benefits between farms.

Changes in streamflow regime due to anthropogenic regulations in the humid tropical Western Ghats, Kerala State, India

Regulation of streamflow by a reservoir creates a flow regime much different from the pre-impoundment period flow regime. Hydro-Electric Projects (HEPs) commissioned in the Western Ghat regions of the Kerala State, India during the last four decades caused considerable changes in the flow regimes of the rivers of the Kerala State in southwest India. In this paper, the Indicators of Hydrologic Alteration (IHA) approach proposed by Richter et al. (1996) is used to analyze flow regime changes in the Periyar and Muvattupuzha Rivers, due to the construction of the Idukki (1976), Idamalayar (1987) and Lower Periyar (1997) HEPs in the high ranges of the Western Ghats. Normal rainfall years (annual rainfall values within mean ± 0.75 standard deviation limits) are only considered in the analysis to focus on hydrologic alterations due to human activities. The mean hydrologic alteration in the Periyar River (deviation from the pre-development hydrologic indicator values) after commissioning of three HEPs is 35%. Inter-basin water transfer after power generation from the Idukki HEP resulted in a higher discharge in the adjacent Muvattupuzha River, leading to considerable changes in the hydro-environment (mean hydrologic alterations varying between 57 to 63%). IHA parameters showing hydrologic alterations above the 67th Percentile were further analyzed. For each of the pre-construction hydrologic parameters ± 1 standard deviation from the mean is set as the upper and lower management target limits. The values of each IHA parameter beyond these targets are considered as non-attainment. Considerable hydrologic alterations are observed, especially for low flows in both basins. Inter-basin transfer induced larger changes in flow parameters compared to intra-basin regulations. The study shows that under a proper water release and diversion scheme, the non-attainment of IHA parameters (values fall beyond the target limits) can be reduced. The findings of the study will be greatly beneficial to regional water management and restoration of an eco-environmental system in the humid tropical region.

Climate driven changes to rainfall and streamflow patterns in a model tropical island hydrological system

summary Rising atmospheric CO2 and resulting warming are expected to impact freshwater resources in the tropics, but few studies have documented how natural stream flow regimes in tropical watersheds will respond to changing rainfall patterns. To address this data gap, we utilized a space-for-time substitution across a naturally occurring and highly constrained (i.e., similar geomorphic, abiotic, and biotic features) model hydrological system encompassing a 3000 mm mean annual rainfall (MAR) gradient on Hawai‘i Island. We monitored stream flow at 15 min intervals in 12 streams across these watersheds for two years (one normal and one dry) and calculated flow metrics describing the flow magnitude, flow variability (e.g., flow flashiness, zero flow days), and flow stability (e.g., deviations from Q90, daily flow range). A decrease in watershed MAR was associated with increased relative rainfall intensity, a greater number of days with zero rainfall resulting in more days with zero flow, and a decrease in Q90:Q50. Flow yield metrics increased with increasing MAR and correlations with MAR were generally stronger in the normal rainfall year compared to the dry year, suggesting that stream flow metrics are less predictable in drier conditions. Compared to the normal rainfall year, during the dry year, Q50 declined and the number of zero flow days increased, while coefficient of variation increased in most streams despite a decrease in stream flashiness due to fewer high flow events. This suggests that if MAR changes, stream flow regimes in tropical watersheds will also shift, with implications for water supply to downstream users and in stream habitat quality for aquatic organisms.

Suitable chickpea cultivars for rainfed situations in black soils of South India

A field study was conducted during winter seasons of 2007–08 and 2008–09 in a randomized block design with three replications to evaluate the performance of chickpea cultivars under rainfed conditions in the Vertisols of Bellary, India. Among the eight varieties evaluated, JG11 and BGD103 outperformed others. During normal to below normal rainfall year of 2007, JG 11 produced 16% higher grain yield over local variety, i.e., A1. During above normal rainfall year of 2008, BGD103 produced 8% higher yield over A1 and 33% higher yield over KAK2. The mean of two years indicates that JG11 and BGD103 produced 9% and 7% higher yields over A1. Among the varieties evaluated JG11 produced higher straw yields of 14.01 and 14.48 q ha−1 during 2007–08 and 2008–09, respectively. Correlation studies indicated that the pod weight, grain weight and total dry matter production per plant determine the chickpea grain yield.

Using Monte Carlo Method for Predicting Rainfall -- Taking Xi'an Area, Shaanxi Province, China, as an Example

Rainfall forecasting plays a vital role in the national economy, social development and human life. Based on Monte Carlo method, this paper uses P- III distribution function to fitting precipitation data in the past 63 years so as to forecast precipitation. Using this model to forecast the rainfall for the past ten years (2003 ~~2013) in Xi'an city, Shaanxi province, China, based on the past 63 years data. The predicted results indicate that the prediction has a high accuracy in normal rainfall year, but in extremely in dry condition and high rainfall year, the relative error is huge. So that，the method is more suitable for the prediction of rainfall in the flat water.

Estimation of water requirement for different crops using CROPWAT model in Anantapur region

Groundwater exploration for irrigation is a costly and scare input in agriculture and plays an important role in increasing food production. Due to over use of groundwater resources, it has become very important to estimate the Crop Water Requirement for different crops. Unscientific and injudicious application of groundwater in the Anantapur region resulted in depletion of the groundwater table. Anantapur region was chosen as the study area as its sever water problem. To achieve effective utilization of the groundwater resources, there is a need to estimate the crop water requirement for different crops at different management levels to accomplish effective irrigation management in the Ananthapur region. It is important that the water requirements of the crops are known. This study was carried out using CROPWAT 8.0 model. The information about climatic conditions, soil types and cropping pattern were obtained in the study area to estimate the crop water requirement under rainfed condition. The crop water requirement for the different crops of Anantapur region is very essential for effective utilization of the groundwater and also to be increase the crop yield. The maximum quantity of effective rainfall observed during the month of September as 79.5 per cent of the monthly rainfall i.e. 101.7 mm and average annual effective rainfall was estimated over the period 1985 to 2012 as 85.5% of the average annual rainfall i.e. 526 mm out of 615.4 mm of average annual rainfall. The crop water requirement for the groundnut Kharif and Rabi crops in the Anantapur region was estimated as 591.3 mm and 443.3mm, respectively and for the vegetables, cotton, rice, grains and maize in the Anantapur region are to be 594.1 mm, 878.6 mm, 1110.6 mm, 699.9 mm and 679.3 mm, respectively. Efficient water management becomes crucial and critical in normal or deficit rainfall years.

A novel approach to estimate direct and indirect water withdrawals from satellite measurements: A case study from the Incomati basin

The Incomati basin encompasses parts of South Africa, Swaziland and Mozambique, and is a water stressed basin. Equitable allocation of water is crucial to sustain livelihoods and agro-ecosystems, and to sustain international agreements. As compliance monitoring of water distribution by flow meters is laborious, expensive and only partially feasible, a novel approach has been developed to estimate water withdrawals using satellite measurements. Direct withdrawals include pumping from rivers, impoundments and groundwater, for irrigation and other human uses. Indirect withdrawals include evaporation processes from groundwater storage, unconfined shallow aquifers, seepage zones, lakes and reservoirs, and inundations, in addition to evaporation from pristine land surface conditions. Indirect withdrawals intercept lateral flow of water and reduce downstream flow. An innovative approach has been developed that employs three main spatial data layers inferred from satellite measurements: land use, rainfall, and evaporation. The evaporation/rainfall ratio was computed for all natural land use classes and used to distinguish between evaporation from rainfall and incremental evaporation caused by water withdrawals. The remote sensing measurements were validated against measured evaporative flux, stream flow pumping volume, and stream flow reductions. Afforested areas in the whole basin was responsible for an indirect withdrawal of 1241Mm3/yr during an average rainfall year while the tripartite agreement among the riparian countries specifies a permitted total withdrawal of 546Mm3/yr. However, the irrigation sector is responsible for direct withdrawals of 555Mm3/yr only while their allocated share is 1327Mm3/yr – the long term total withdrawals are thus in line with the tripartite agreement. South Africa withdraws 1504Mm3/yr while their share is 1261Mm3/yr. The unmetered stream flow reduction from the afforested areas in South Africa represents the big uncertainty factor. The methodology described using remotely sensed measurements to estimate direct and indirect withdrawals has the potential to be applied more widely to water stressed basins having limited availability of field data.

Energy, economics, and water use efficiency of chickpea (Cicer arietinum L.) cultivars in Vertisols of semi-arid tropics, India

Pulses play a major role in providing overall prosperity to the small and marginal farmers through nutritional security by meeting their dietary protein requirements and improving production base through conservation of natural resources. Inclusion of pulses in the cropping system as a crop rotation improves soil fertility and crop productivity of cereals and oil seeds. Chickpea is one of the important pulses cultivated in Vertisols during winter season. We examined chickpea cultivars for energy use efficiency, economics, physiological efficiency and water use efficiency (WUE) under different rainfall situations for their sustainable yield and overall profit, in Vertisols of semi-arid tropics of South India. Results revealed that low input energy and high grain and stover yields of cultivars result in higher total output energy and net benefit energy. Higher dry matter efficiency of 0.702 was observed with medium-duration cultivar, whereas WUE was higher in short-duration cultivar followed by medium-duration cultivar. We conclude that medium- duration cultivar and short-duration cultivar are more suitable for the SAT region in terms of greater energy benefits, higher income per unit area, physiological efficiency and water use efficiency. Thus short-duration cultivar could be cultivated during normal to above normal rainfall years and during normal to drought years in winter season on residual soil moisture in Vertisols medium-duration cultivar for higher energy efficiency and economics.

Participatory Planning of Appropriate Rainwater Harvesting and Management Techniques in the Central Rift Valley Dry Lands of Ethiopia

Despite the extensive efforts of rainwater harvesting and management (RWHM) interventions for moisture-stressed areas in Ethiopia, the adoption and wider dissemination of the newly introduced techniques have been generally meager. The objective of this study was, therefore, to develop appropriate RWHM techniques through a participatory planning process in the Central Rift Valley (CRV) dry lands of Ethiopia. To achieve this objective, a combination of literature reviews, focus group discussions, questionnaire surveys, agro-meteorological analyses and field experimentations were undertaken. Perceived agro-meteorological challenges were determined through the questionnaire survey and validated through meteorological data analyses. Potential in situ RWHM techniques were selected in a participatory process and field-tested for two consecutive growing seasons to evaluate their performances. Those techniques which were selected in a participatory process showed statistically higher crop yields than the existing practices under both low and normal rainfall years. The result of this study implied that the introduction of new RWHM techniques can be successful when they are adjusted and modified in accordance with the existing tillage, hoeing and related land management practices. It was concluded that participatory planning of in situ RWHM techniques allows both the utilization of existing knowledge and opportunities while empowering the farmers to select and introduce new practices as per the existing socioeconomic and environmental settings. The new participatory planning approach will augment the recent efforts of promoting various types of RWHM techniques for improved rainfed agriculture in the vast dry lands of Ethiopia.

Use of agave by desert bighorn sheep

Abstract We hypothesized that, if agave (Agave) were used by desert ungulates as a source of moisture, they would be used more during drought than during periods with average or above-average rainfall. From 2004–2012, we counted the number of stalks of agave used by Nelson's bighorn sheep (Ovis canadensis nelsoni) in 10.3 ha in Deep Canyon, Santa Rosa Mountains, California. During years of average or above-average rainfall, bighorn sheep consumed <3% of available stalks of agave. During years with rainfall below average, bighorn sheep consumed from 20–53% of available stalks of agave, thus supporting our hypothesis.

Influence of Northwest Cloudbands on Southwest Australian Rainfall

Northwest cloudbands are tropical-extratropical feature that crosses the Australian continent originating from Australia’s northwest coast and develops in a NW-SE orientation. In paper, atmospheric and oceanic reanalysis data (NCEP) and Reynolds reconstructed sea surface temperature data were used to examine northwest cloudband activity across the Australian mainland. An index that reflected the monthly, seasonal, and interannual activity of northwest cloudbands between 1950 and 1999 was then created. Outgoing longwave radiation, total cloud cover, and latent heat flux data were used to determine the number of days when a mature northwest cloudband covered part of the Australian continent between April and October. Regional indices were created for site-specific investigations, especially of cloudband-related rainfall. High and low cloudband activity can affect the distribution of cloudbands and their related rainfall. In low cloudband activity seasons, cloudbands were mostly limited to the south and west Australian coasts. In high cloudband activity seasons, cloudbands penetrated farther inland, which increased the inland rainfall. A case study of the southwest Australian region demonstrated that, in a below average rainfall year, cloudband-related rainfall was limited to the coast. In an above average rainfall year, cloudband-related rainfall occurred further inland.

Satellite earth observation as a tool to conceptualize hydrogeological fluxes in the Sandveld, South Africa

In semi-arid, groundwater-dependent regions of South Africa, allocation of additional water resources can become problematic in the absence of quantified regional groundwater recharge values. In this study in the northern Sandveld, remote-sensing-data products for precipitation (P) and evapotranspiration (ET) are used to quantify groundwater recharge and guide the conceptualization of the hydrogeology of the study area. Data from three ET models (ETMODIS, MOD16, Pitman rainfall-runoff) are compared; these models concur best in years of average rainfall, with model results deviating up to 30 % in wet years. The MODIS data product (MOD16) is used in conjunction with gridded precipitation data to calculate spatial regional recharge. The long-term precipitation minus evapotranspiration (P–ET) budget closes on a positive 13 ± 25 %; however, when correcting ET (20 % underestimation determined using the chloride mass balance method), the catchment average potential recharge is reduced to −4 ± 30 %. The use of P–ET clearly identifies potential recharge zones at higher elevation and discharge zones, highlighting irrigated agriculture. The usefulness of identifying recharge zones is demonstrated in the value added to conceptualizing the hydrogeology. Since some uncertainty around the accuracy of ET data still remains, it is recommended that the MODIS data product be validated more comprehensively in semi-arid environments.

Role of the Himalayan Orography in Simulation of the Indian Summer Monsoon using RegCM3

In this study, sensitivity of the Indian summer monsoon simulation to the Himalayan orography representation in a regional climate model (RegCM) is examined. The prescribed height of the Himalayan orography is less in the RegCM model than the actual height of the Himalayas. Therefore, in order to understand the impact of the Himalayan orography representation on the Indian summer monsoon, the height of the Himalayan orography is increased (decreased) by 10 % from its control height in the RegCM model. Three distinct monsoon years such as deficit (1987), excess (1988) and normal rainfall years are considered for this study. The performance of the RegCM model is tested with the use of a driving force from the reanalysis data and a global model output. IMD gridded rainfall and the reanalysis-2 data are used as verification analysis to validate the model results. The RegCM model has the potential to represent mean rainfall distribution over India as well as the upper air circulation patterns and some of the semi-permanent features during the Indian summer monsoon season. The skill of RegCM is reasonable in representing the variation in circulation and precipitation pattern and intensity during two contrasting rainfall years. The simulated seasonal mean rainfall over many parts of India especially, the foothills of the Himalaya, west coast of India and over the north east India along with the whole of India are more when the orography height is increased. The low level southwesterly wind including the Somali jet stream as well as upper air circulation associated with the tropical easterly jet stream become stronger with the enhancement of the Himalayan orography. Statistical analysis suggests that the distribution and intensity of rainfall is represented better with the increased orography of RegCM by 10 % from its control height. Thus, representation of the Himalayan orography in the model is close to actual and may enhance the skill in seasonal scale simulation of the Indian summer monsoon.

Impact of Rainfall Pattern on Native Arbuscular-Mycorrhizal Activity Influencing Phosphorus Utilization by Direct Seeded Rainfed Upland Rice (Oryza sativa L.)

Efficacy of native arbuscular mycorrhiza to support phosphorus nutrition of rainfed upland rice was assessed under various rainfall patterns. Native arbuscular-mycorrhiza aided phosphorus acquisition by rainfed upland rice (Oryza sativa L.), over the period of 6 years (in alternate year’s between 1999 and 2009) having variable rainfall pattern, under rice mono-cropping and potential arbuscular-mycorrhiza-supportive rice based rotations were compared. Among these, the 2 years rotation of maize (Zea mays L.) relay cropped by horse gram (Dolichos biflorus L.) in the first year and followed by upland rice in the second year was most mycorrhiza-supportive. While phosphorus uptake in rice was positively correlated (r = 0.6301–0.7821) with the extent of mycorrhizal colonization under various crop rotations, the extent of influence of arbuscular-mycorrhizal colonization was greater in less rainfall year of 2009 (R 2 = 0.5450) than normal rainfall year of 2007 (R 2 = 0.3971). The mycorrhizal advantage to rice under most mycorrhiza supportive crop rotation (maize-horse gram-rice), in terms of mycorrhiza-aided phosphorus acquisition efficiency, on the other hand, was negatively correlated (r = −0.684 to −0.799) with the amount of rainfall received over a period under study (6 years), confirming higher mycorrhizal efficacy under moisture stress. The analysis emphasized the potential of exploiting native arbuscular mycorrhizal fungi as climate resilient agricultural technology component in rainfed ecology under the present climate change scenario leading to reducing moisture availability.

Factors Influencing Foraging Habitats of Mule Deer (Odocoileus hemionus) in the San Andres Mountains, New Mexico

Abstract We documented characteristics of habitats and related these to foraging needs of mule deer (Odocoileus hemionus) in the San Andres Mountains, Dona Ana, Sierra, and Socorro counties, New Mexico. Cover by forbs was related positively to rainfall during the primary growing season in mixed-lowland scrub, sand sagebrush (Artemisia filifolia), alkali sacaton (Sporobolus airoides), and creosotebush (Larrea tridentata) habitats. Cover by palatable and preferred forages was low (≤8.6%) in 2004, 2005, and 2007, years of average rainfall, and increased slightly in 2006 (≤9.3%) during above-average rainfall. During years of average rainfall, cover by forbs was related negatively to percentage cover by shrubs, to density of honey mesquite (Prosopis glandulosa), sand sagebrush, and grama grass (Bouteloua), and to canopy and density of trees in pinyon–juniper (Pinus–Juniperus) woodlands. Important species of browse were in all habitats, but only grama grass (n = 9), pinyon–juniper (n = 12), and oak–mountain mah...

The Effects of Extreme Drought on Native Forage Nutritional Quality and White-Tailed Deer Diet Selection

Forage availability is often used as a measure of habitat quality for Odocoi- leus virginianus (White-tailed Deer; hereafter Deer). Many studies have evaluated treatment effects on forage availability, but the effects of other abiotic factors, such as drought, on native forages and Deer diet selection are poorly understood. We measured diet selection and nutritional quality of commonly occurring forages following extreme drought (2007) and normal rainfall years (2008) in 4 closed-canopied hardwood stands in the Central Hardwoods region. Deer selected 6 forage species in both years of the study. Within these 6 species, crude protein (CP) and acid detergent fiber (ADF) were not different, and neutral detergent fiber (NDF) increased during the year of normal rainfall. Thirteen other commonly occurring forages showed a different trend, with CP negatively affected by drought and ADF and NDF unaffected. Less-selected species in the drought year and a greater selection-index cut-off value suggest Deer were more selective of species consumed during extreme drought because fewer plants met their nutritional requirements. Our data support the selective quality hypothesis, predicting Deer become more selective of plant species to meet nutritional requirements when resources are lim- ited. Our data suggest more frequent and intense droughts predicted as a result of global climate change may influence diet selection of deer and decrease forage quality enough to limit lactation during the late-summer stress period in the Southeast.