N. Van Gestel

Texas Tech University | TTU · Department of Biological Sciences

High daily temperature range of soil (DTRsoil) negatively affects soil microbial biomass and activity, but its interaction with seasonal soil moisture in regulating ecosystem function remains unclear. For our 5-year field study in the Chihuahuan Desert, we suspended shade cloth 15 cm above the soil surface to reduce daytime temperature and increase...

One of the primary challenges of our time is to feed a growing and more demanding world population with reduced external inputs and minimal environmental impacts, all under more variable and extreme climate conditions in the future. Conservation agriculture represents a set of three crop management principles that has received strong international...

Bacteria grow and transform elements at different rates, yet quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to Stable Isotope Probing (SIP) that enables determining...

Maximum and minimum soil temperatures affect belowground processes. In the past 50 years in arid regions, measured reductions in the daily temperature range of air (DTR(air)) most likely generated similar reductions in the unmeasured daily temperature range of soil (DTR(soil)). However, the role of DTR(soil) in regulating microbial and plant proces...

This on-farm study was conducted to assess the impact of six prevalent crop management practices adopted by growers in West Texas on various indicators of soil health. This study is a part of a citizen science project, where we collaborated with cotton growers who helped with standardized sample and data collection from 2017 to 2022. This project a...

Texas cotton production is facing challenges from increased temperatures and extended droughts. We sought to determine whether applying a multi-species grass mulch on the surface of cotton fields in a semiarid region would mitigate some of the negative effects of climate change. We used open-top chambers (OTCs) to mimic climate warming and compared...

Texas cotton production is facing challenges arising from increased temperatures and extended droughts. One potential solution to mitigate these environmental stresses lies in enhancing soil health through measures aimed at increasing soil organic matter and microbial biomass. Our field study investigated the effectiveness of adding residue on soil...

Winter cover crops represent a land cover change that may sequester carbon in the soil and improve agricultural sustainability. Their adoption may also change the Earth's radiative balance and result in biophysical feedbacks to climate through alterations in albedo and latent heat fluxes. Understanding the mechanisms underlying these alterations to...

Ice-free terrestrial environments of the western Antarctic Peninsula are expanding and subject to colonization by new microorganisms and plants, which control biogeochemical cycling. Measuring growth rates of microbial populations and ecosystem carbon flux is critical for understanding how terrestrial ecosystems in Antarctica will respond to future...

Understanding the chemical composition of our planet's crust was one of the biggest questions of the 20th century. More than 100 years later, we are still far from understanding the global patterns in the bioavailability and spatial coupling of elements in topsoils worldwide, despite their importance for the productivity and functioning of terrestr...

In the age of big data, soil data are more available and richer than ever, but – outside of a few large soil survey resources – they remain largely unusable for informing soil management and understanding Earth system processes beyond the original study. Data science has promised a fully reusable research pipeline where data from past studies are u...

In the age of big data, soil data are more available than ever, but -outside of a few large soil survey resources- remain largely unusable for informing soil management and understanding Earth system processes outside of the original study. Data science has promised a fully reusable research pipeline where data from past studies are used to context...

The monarch butterfly (Danaus plexippus) is among the best-known insects in the world, renowned for its conspicuousness, spectacular migration, and interesting biology. Unfortunately, monarch populations have declined dramatically due, in large part, to the widespread losses of the milkweed plants which they depend upon for reproduction. This has l...

The carbon stored in soil exceeds that of plant biomass and atmospheric carbon and its stability can impact global climate. Growth of decomposer microorganisms mediates both the accrual and loss of soil carbon. Growth is sensitive to temperature and given the vast biological diversity of soil microorganisms, the response of decomposer growth rates...

Plants may slow global warming through enhanced growth, thereby stimulating the land carbon (C) sink. However, the key drivers determining responses of plants to warming remain unclear, causing uncertainty in climate projections. Using meta- analysis, we show that the effect of experimental warming on plant biomass is best explained by soil nitroge...

Plants may slow global warming through enhanced growth, because increased levels of photosynthesis stimulate the land carbon (C) sink. However, the key drivers determining responses of plants to warming remain unclear, causing uncertainty in climate projections. Using meta- analysis, we show that the effect of experimental warming on plant biomass...

The Transylvanian Plain (TP), Romania is widely used for agronomic production. The Chernisol soil class covers a vast majority of the TP as defined by the Sistemul Roman De Taxonomie A Solurilor (SRTS). Chernisols are fertile, dark soils similar to Mollisols in the United States. Chernisols have four key soil types, two of them occur in the TP: che...

Liming is often applied to alleviate soil acidification and increase crop yield on acidic soils, but its effect on soil phosphorus (P) availability is unclear, particularly in rice paddies. The objective of this study was to examine the effect of liming on rice production, yield and P uptake in a three-year field experiment in a double rice croppin...

Background: The monarch butterfly (Danaus plexippus) is a conspicuous insect that has experienced a drastic population decline over the past two decades. While there are several factors contributing to dwindling monarch populations, habitat loss is considered the most significant threat to monarchs. In the United States, loss of milkweed, particul...

The western Antarctic Peninsula is an extreme low temperature environment that is warming rapidly due to global change. Little is known, however, about the temperature sensitivity of growth of microbial communities in Antarctic soils and in the surrounding oceanic waters. This is the first study that directly compares temperature adaptation of adja...

Quantitative stable isotope probing (qSIP) measures rates of taxon-specific element assimilation in intact microbial communities, utilizing substrates labeled with a heavy isotope.The laboratory protocol for qSIP is nearly identical to that for conventional stable isotope probing, with two key additions: (1) in qSIP, qPCR measurements are conducted...

Liming is a common practice to alleviate soil acidification in agricultural systems worldwide. Because liming affects soil microbial activity and soil carbon (C) input rates, it can affect soil greenhouse gas (GHG) emissions as well. However, little is known about the effect of liming on GHG emissions from rice agriculture, one of the main sources...

Understanding how population-level dynamics contribute to ecosystem-level processes is a primary focus of ecological research and has led to important breakthroughs in the ecology of macroscopic organisms. However, the inability to measure population-specific rates, such as growth, for microbial taxa within natural assemblages has limited ecologist...

Liming and straw retention are often applied to increase yield in rice cropping systems on acidic soils. Although these practices affect soil fertility and rice growth through different mechanisms, it is still unclear whether or how these two management practices interact. Here we report on the first experiment to study the interaction between limi...

Aridisols are the dominant soil type in drylands, which occupy one-third of Earth's terrestrial surface. We examined controls on biogeographical patterns of Aridisol prokaryotic (Bacterial and Archaeal) communities at a regional scale by comparing communities from 100 Aridisols throughout the southwestern United States using high-throughput sequenc...

Carbon storage by ecosystems is valuable for climate protection. Biodiversity conservation may help increase carbon storage, but the value of this influence has been difficult to assess. We use plant, soil, and ecosystem carbon storage data from two grassland biodiversity experiments to show that greater species richness increases economic value: I...

Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more com...

No-till agriculture represents a relatively widely adopted management system that aims to reduce soil erosion, decrease input costs, and sustain long-term crop productivity. However, its impacts on crop yields are variable, and an improved understanding of the factors limiting productivity is needed to support evidence-based management decisions. W...

Bacteria grow and transform elements at different rates, yet quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to Stable Isotope Probing (SIP) that enables determining...

Bacteria grow and transform elements at different rates, yet quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to Stable Isotope Probing (SIP) that enables determining...

As a key component of the carbon cycle, soil CO2 efflux (SCE) is being increasingly studied to improve our mechanistic understanding of this important carbon flux. Predicting ecosystem responses to climate change often depends on extrapolation of current relationships between ecosystem processes and their climatic drivers to conditions not yet expe...

We quantified fluctuations in the status of individual patches (wetlands) in supporting connectivity within a network of playas, temporary wetlands of the southern Great Plains of North America that are loci for regional biodiversity. We used remote sensing imagery to delineate the location of surface waters in >8,000 playa basins in a ~31,900 km2...

As a key component of the carbon cycle, soil CO2 efflux (SCE) is being increasingly studied to improve our mechanistic understanding of this important carbon flux. Predicting ecosystem responses to climate change often depends on extrapolation of current relationships between ecosystem processes and their climatic drivers to conditions not yet expe...

Background/Question/Methods Reduction in daily temperature variability has been predicted as one of the side effects of climate change in many climate models. Different field studies have supported the predictions by observing the increase of daily minimum temperatures at a significantly higher rate than daily maximum temperatures. Although this...

During the first few years of elevated atmospheric [CO2] treatment at the Nevada Desert FACE Facility, photosynthetic downregulation was observed in desert shrubs grown under elevated [CO2], especially under relatively wet environmental conditions. Nonetheless, those plants maintained increased A sat (photosynthetic performance at saturating light...

The temperature response of soil respiration in deserts is not well quantified. We evaluated the response of respiration to temperatures spanning 67°C from seven deserts across North America and Greenland. Deserts have similar respiration rates in dry soil at 20°C, and as expected, respiration rates are greater under wet conditions, rivaling rates...

Background/Question/Methods Anthropogenic nitrogen (N) deposition in arid ecosystems is relatively low when compared to mesic systems. However, because arid ecosystems are characterized by low precipitation and high potential evoaptranspiration rates (PET) in addition to nutrient limitations additional anthropogenic N deposition will likely have m...

Background/Question/Methods Mean global surface temperatures have risen by 0.74 °C in the past century, partially due to daily minimum temperatures increasing proportionately greater than daily maximum temperatures. Alterations in daily temperature dynamics have been attributed to greater water vapor in the atmosphere, which dampens temperature e...

Background/Question/Methods Arid regions in southwestern US are predicted to experience increases in surface air temperatures and reduced annual rainfall (IPCC 2007). It is well established that soil moisture is an important driving variable of desert ecosystem functioning. Generally, with sufficient soil moisture, soil microbial activity is enhan...

Global climate models predict that in the next century precipitation in desert regions of the USA will increase, which is anticipated to affect biosphere/atmosphere exchanges of both CO(2) and H(2)O. In a sotol grassland ecosystem in the Chihuahuan Desert at Big Bend National Park, we measured the response of leaf-level fluxes of CO(2) and H(2)O 1...

Onions were grown in environmentally controlled growth chambers for 85 days to investigate the effect of relatively low light intensity (350 µmol m−2 s−1) at two different total irradiance periods (12-h and 24-h photoperiods) on growth and photosynthetic performance. To test whether photosynthetic downregulation occurred due to carbohydrate feedbac...

We examined six river reaches in western Tennessee over a two-year period to determine how channel alteration affected floodplain hydrology and nutrient pools. Four sites, two depression and two non-depression, were established on the floodplains of each river, and data on vegetation, water table depth, redox potential, and soil and leaf nutrient p...