Browsing by Author "van Gestel, Natasja (TTU)"
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Item Bioavailability of Macro and Micronutrients Across Global Topsoils: Main Drivers and Global Change Impacts(2023) Ochoa-Hueso, Raúl; Delgado-Baquerizo, Manuel; Risch, Anita C.; Ashton, Louise; Augustine, David; Bélanger, Nicolas; Bridgham, Scott; Britton, Andrea J.; Bruckman, Viktor J.; Camarero, J. Julio; Cornelissen, Gerard; Crawford, John A.; Dijkstra, Feike A.; Diochon, Amanda; Earl, Stevan; Edgerley, James; Epstein, Howard; Felton, Andrew; Fortier, Julien; Gagnon, Daniel; Greer, Ken; Griffiths, Hannah M.; Halde, Caroline; Hanslin, Hans Martin; Harris, Lorna I.; Hartsock, Jeremy A.; Hendrickson, Paul; Hovstad, Knut Anders; Hu, Jia; Jani, Arun D.; Kent, Kelcy; Kerdraon-Byrne, Deirdre; Khalsa, Sat Darshan S.; Lai, Derrick Y.F.; Lambert, France; LaMontagne, Jalene M.; Lavergne, Stéphanie; Lawrence, Beth A.; Littke, Kim; Leeper, Abigail C.; Licht, Mark A.; Liebig, Mark A.; Lynn, Joshua S.; Maclean, Janet E.; Martinsen, Vegard; McDaniel, Marshall D.; McIntosh, Anne C.S.; Miesel, Jessica R.; Miller, Jim; Mulvaney, Michael J.; Moreno, Gerardo; Newstead, Laura; Pakeman, Robin J.; Pergl, Jan; Pinno, Bradley D.; Piñeiro, Juan; Quigley, Kathleen; Radtke, Troy M.; Reed, Paul; Rolo, Víctor; Rudgers, Jennifer; Rutherford, P. Michael; Sayer, Emma J.; Serrano-Grijalva, Lilia; Strack, Maria; Sukdeo, Nicole; Taylor, Andy F.S.; Truax, Benoit; Tsuji, Leonard J.S.; van Gestel, Natasja (TTU); Vaness, Brenda M.; Van Sundert, Kevin; Vítková, Michaela; Weigel, Robert; Wilton, Meaghan J.; Yano, Yuriko; Teen, Ewing; Bremer, EricUnderstanding 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 terrestrial ecosystems. Here, we measured the bioavailability and coupling of thirteen macro- and micronutrients and phytotoxic elements in topsoils (3–8 cm) from a range of terrestrial ecosystems across all continents (∼10,000 observations) and in response to global change manipulations (∼5,000 observations). For this, we incubated between 1 and 4 pairs of anionic and cationic exchange membranes per site for a mean period of 53 days. The most bioavailable elements (Ca, Mg, and K) were also amongst the most abundant in the crust. Patterns of bioavailability were biome-dependent and controlled by soil properties such as pH, organic matter content and texture, plant cover, and climate. However, global change simulations resulted in important alterations in the bioavailability of elements. Elements were highly coupled, and coupling was predictable by the atomic properties of elements, particularly mass, mass to charge ratio, and second ionization energy. Deviations from the predictable coupling-atomic mass relationship were attributed to global change and agriculture. Our work illustrates the tight links between the bioavailability and coupling of topsoil elements and environmental context, human activities, and atomic properties of elements, thus deeply enhancing our integrated understanding of the biogeochemical connections that underlie the productivity and functioning of terrestrial ecosystems in a changing world.Item The economic value of grassland species for carbon storage(2017) Hungate, Bruce A.; Barbier, Edward B.; Ando, Amy W.; Marks, Samuel P.; Reich, Peter B.; van Gestel, Natasja (TTU); Tilman, David; Knops, Johannes M. H.; Hooper, David U.; Butterfield, Bradley J.; Cardinale, Bradley J.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: Increasing species richness from 1 to 10 had twice the economic value of increasing species richness from 1 to 2. The marginal value of each additional species declined as species accumulated, reflecting the nonlinear relationship between species richness and plant biomass production. Our demonstration of the economic value of biodiversity for enhancing carbon storage provides a foundation for assessing the value of biodiversity for decisions about land management. Combining carbon storage with other ecosystem services affected by biodiversity may well enhance the economic arguments for conservation even further.Item Winter cover cropping increases albedo and latent heat flux in a Texas High Plains agroecosystem(2024) McNellis, Risa (TTU); van Gestel, Natasja (TTU); Thomas, R. Quinn; Smith, Nicholas G. (TTU)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 the radiative balance is important for making reliable future climate projections. However, data on cover crop biophysics are limited, requiring models to rely on data from summer plants for parameterization, likely biasing predictions. To address this gap, we measured the albedo and stomatal conductance of two summer crops and three winter crops on farms in the High Plains region of Texas. We also established a winter cover crop field experiment with two cover crops and fallow fields to estimate the change in albedo and latent heat flux that results from a switch to winter cover cropping. We found that albedo was significantly higher in winter-like conditions than in summer-like conditions due to an increase in plant albedo and a reduction in leaf area index. The albedo of winter cover crops was higher than the soil albedo, resulting in an increase in top-of-atmosphere reflected radiation of 7%–14% when converting from fallow fields to winter cover cropped fields. There was an additional cooling effect through doubling of the estimated latent heat flux caused by the presence of cover crops. The combined changes in albedo and latent heat resulted in a change in the surface energy balance that is associated with an overall cooling effect of winter cover crops on surface atmospheric temperatures. While this effect is likely to be region-specific, these results strongly indicate that winter cover crops alter the surface albedo and latent heat flux of agricultural fields and provide a direct cooling effect in the High Plains region of Texas.