Life Sciences Commons^™

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

Biology Faculty Publications and Presentations

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …

Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis

Biology Faculty Publications and Presentations

Cover crops are a sustainable management tool for mediating weed pressure, reducing soil erosion, and enhancing soil organic carbon (C) and nitrogen (N) levels. Yet, adoption rates across water-limited farms in Texas remain low, especially among producers without irrigation access, due to concerns that cover crop use of soil moisture will negatively impact subsequent cash crop yields. This three-year cover crop trial in a rain-fed sorghum (Sorghum bicolor L.) farm in Lyford, Texas, trialed different cover crop mixes and seeding rates and confirmed that cover cropping leads to significant soil moisture deficits and cash crop failure when rainfall is low …

Sodah: The Soils Data Harmonization Database, An Open-Source Synthesis Of Soil Data From Research Networks, Version 1.0, Marie-Anne De Graaff

Biology Faculty Publications and Presentations

Data collected from research networks present opportunities to test theories and develop models about factors responsible for the long-term persistence and vulnerability of soil organic matter (SOM). Synthesizing datasets collected by different research networks presents opportunities to expand the ecological gradients and scientific breadth of information 55 available for inquiry. Synthesizing these data, are challenging, especially considering the legacy of soils data that has already been collected and an expansion of new network science initiatives. To facilitate this effort, here we present the SOils DAta Harmonization database (SoDaH; https://lter.github.io/som-website, last accessed 15 July 2020), a flexible database designed to harmonize …

A Record Of Vapour Pressure Deficit Preserved In Wood And Soil Across Biomes, Adrian Broz, Gregory J. Retallack, Toby M. Maxwell, Lucas C.R. Silva

Biology Faculty Publications and Presentations

The drying power of air, or vapour pressure deficit (VPD), is an important measurement of potential plant stress and productivity. Estimates of VPD values of the past are integral for understanding the link between rising modern atmospheric carbon dioxide (pCO₂) and global water balance. A geological record of VPD is needed for paleoclimate studies of past greenhouse spikes which attempt to constrain future climate, but at present there are few quantitative atmospheric moisture proxies that can be applied to fossil material. Here we show that VPD leaves a permanent record in the slope (S) of least-squares …

Soil Biotic And Abiotic Conditions Negate Invasive Species Performance In Native Habitat, Pushpa Soti, Matthew Purcell, Krish Jayachandran

Biology Faculty Publications and Presentations

Background: Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats. However, the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats. While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats, our understanding of belowground environment of invasive species in their native habitats is very limited. In this study, we analyzed soil characteristics associated with an exotic invasive plant, Old World Climbing Fern (Lygodium microphyllum), in its native habitat in Australia and the …

Agricultural And Environmental Weeds Of South Texas And Their Management, Pushpa Soti, John A. Goolsby, Alexis Racelis

Biology Faculty Publications and Presentations

The Lower Rio Grande Valley (LRGV) in south Texas is one of the most productive agricultural regions in southern United States. With subtropical climate and highly fertile soils, this region provides a year-round growing condition for crops. Along with citrus, major crops grown in the region are sorghum cotton and corn in the summer and vegetables in winter. Thus, a fallow period of 3-6 months between successive crops is common in the region. Growers in this region report weeds as their number one economic and agronomic problem affecting crop yield and quality and increasing the cost of production and weeds …

Laguna Madre Estuary Program Environmental Strategic Plan - Final Report, Kim D. Jones, Lucy Camacho, T. Sinha, Omar Al-Qudah, Hudson R. Deyoe, Augusto Sanchez Gonzalez, Jungseok Ho, Javier Guerrero

Biology Faculty Publications and Presentations

The goal of this effort is to establish a framework of fundamental information and critical ideas to serve as a basis to assist in supporting legislation to found the 29th National Estuary Program for the Laguna Madre of the Gulf coast of Texas.

The National Estuary Program (NEP) was established by the Clean Water Act Amendments of 1987 (Section 320) to protect nationally significant estuaries threatened by development, pollution and overuse. The U.S. Environmental Protection Agency administers the NEP. The Corpus Christi Bay NEP (now the Coastal Bend Bays and Estuary Program) was among the last estuaries accepted into the …

Modeled Inflow Validation & Nutrient Loading Estimation In Two Subwatersheds Of The Lower Laguna Madre, Hudson R. Deyoe, Warren Pulich, Nelun Fernando

Biology Faculty Publications and Presentations

University of Texas Rio Grande Valley will characterize nutrient loading rates into the Lower Laguna Madre for subwatersheds by monitoring stream flow and water quality (particularly total nitrogen and phosphorus). This information will be used to evaluate Texas Rainfall-Runoff model performance in estimating ungaged inflows and to establish a relationship between ungaged inflows and nutrient loading regimes to the Lower Laguna Madre. View on Map

A Meta-Analysis Of Soil Biodiversity Impacts On The Carbon Cycle, M.-A. De Graaff, J. Adkins, P. Kardol, H. L. Throop

Biology Faculty Publications and Presentations

Loss of biodiversity impacts ecosystem functions, such as carbon (C) cycling. Soils are the largest terrestrial C reservoir, containing more C globally than the biotic and atmospheric pools together. As such, soil C cycling, and the processes controlling it, has the potential to affect atmospheric CO₂ concentrations and subsequent climate change. Despite the growing evidence of links between plant diversity and soil C cycling, there is a dearth of information on whether similar relationships exist between soil biodiversity and C cycling. This knowledge gap occurs even though there has been increased recognition that soil communities display high levels of …

Isolation Of Diverse Members Of The Aquificales From Geothermal Springs In Tengchong, China, Brian P. Hedlund, Anna-Louise Reysenbach, Liuquin Huang, John C. Ong, Zizhang Liu, Jeremy A. Dodsworth, Reham Ahmed, Amanda J. Williams, Brandon R. Briggs, Yitai Liu, Weiguo Hou, Hailiang Dong

Biology Faculty Publications and Presentations

The order Aquificales (phylum Aquificae) consists of thermophilic and hyperthermophilic bacteria that are prominent in many geothermal systems, including those in Tengchong, Yunnan Province, China. However, Aquificales have not previously been isolated from Tengchong. We isolated five strains of Aquificales from diverse springs (temperature 45.2–83.3°C and pH 2.6–9.1) in the Rehai Geothermal Field from sites in which Aquificales were abundant. Phylogenetic analysis showed that four of the strains belong to the genera Hydrogenobacter, Hydrogenobaculum, andSulfurihydrogenibium, including strains distant enough to likely justify new species ofHydrogenobacter and Hydrogenobaculum. The additional strain may represent a …

Virus Silicification Under Simulated Hot Spring Conditions, James R. Laidler, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).