@misc{MaWeberRaggioQuilezetal., author = {Ma, Yunyao and Weber, Bettina and Raggio Qu{\´i}lez, Jos{\´e} and Colesie, Claudia and Veste, Maik and Bader, Maaike Y. and Porada, Philipp}, title = {Determining key drivers of the annual carbon budget of biocrusts in different climatic zones}, series = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, journal = {EGU General Assembly 2022, Vienna, Austria \& Online | 23-27 May 2022}, doi = {10.5194/egusphere-egu22-3714}, abstract = {Biocrusts are distributed over all climate zones of the world and they substantially contribute to ecosystem functioning. Their growth, determined by their carbon balance, can be affected by various climatic drivers. The effects of individual drivers are clear from laboratory experiments, but the relative importance of different drivers along climatic gradients and their underlying mechanisms are largely unknown. Moreover, the effects of seasonal acclimation on the annual carbon balance are not fully understood either. Therefore, we aim at determining the level and variation of annual biocrust carbon balances and their connection to climatic drivers along environmental gradients. In addition, we explore the role that acclimation plays in the carbon balance of biocrusts}, language = {en} } @misc{MaWeberKratzetal., author = {Ma, Yunyao and Weber, Bettina and Kratz, Alexandra and Raggio, Jos{\´e} and Colesie, Claudia and Veste, Maik and Bader, Maaike Y. and Porada, Philipp}, title = {Exploring environmental and physiological drivers of the annual carbon budget of biocrusts from various climatic zones with a mechanistic data-driven model}, series = {Biogeosciences}, volume = {20}, journal = {Biogeosciences}, number = {13}, issn = {1726-4189}, doi = {10.5194/bg-20-2553-2023}, pages = {2553 -- 2572}, abstract = {Biocrusts are a worldwide phenomenon, contributing substantially to ecosystem functioning. Their growth and survival depend on multiple environmental factors, including climatic ones, and the relations of these factors to physiological processes. Responses of biocrusts to individual environmental factors have been examined in a large number of field and laboratory experiments. These observational data, however, have rarely been assembled into a comprehensive, consistent framework that allows quantitative exploration of the roles of multiple environmental factors and physiological properties for the performance of biocrusts, in particular across climatic regions. Here we used a data-driven mechanistic modelling framework to simulate the carbon balance of biocrusts, a key measure of their growth and survival. We thereby assessed the relative importance of physiological and environmental factors for the carbon balance at six study sites that differ in climatic conditions. Moreover, we examined the role of seasonal acclimation of physiological properties using our framework, since the effects of this process on the carbon balance of biocrusts are poorly constrained so far. We found substantial effects of air temperature, CO2 concentration, and physiological parameters that are related to respiration on biocrust carbon balance, which differ, however, in their patterns across regions. The ambient CO2 concentration is the most important factor for biocrusts from drylands, while air temperature has the strongest impact at alpine and temperate sites. Metabolic respiration cost plays a more important role than optimum temperature for gross photosynthesis at the alpine site; this is not the case, however, in drylands and temperate regions. Moreover, we estimated a small annual carbon gain of 1.5  by lichen-dominated biocrust and 1.9  by moss-dominated biocrust at a dryland site, while the biocrusts lost a large amount of carbon at some of the temperate sites (e.g. -92.1 for lichen-dominated and -74.7  for moss-dominated biocrust). These strongly negative values contradict the observed survival of the organisms at the sites and may be caused by the uncertainty in environmental conditions and physiological parameters, which we assessed in a sensitivity analysis. Another potential explanation for this result may be the lack of acclimation in the modelling approach, since the carbon balance can increase substantially when testing for seasonally varying parameters in the sensitivity analysis. We conclude that the uncertainties in air temperature, CO2 concentration, respiration-related physiological parameters, and the absence of seasonal acclimation in the model for humid temperate and alpine regions may be a relevant source of error and should be taken into account in future approaches that aim at estimating the long-term biocrust carbon balance based on ecophysiological data.}, language = {en} } @misc{PoradaBaderBerdugoetal., author = {Porada, Philipp and Bader, Maaike Y. and Berdugo, Monica B. and Colesie, Claudia and Ellis, Christopher J. and Giordani, Paolo and Herzschuh, Ulrike and Ma, Yunyao and Launiainen, Samuli and Nascimbene, Juri and Petersen, Imke and Raggio Qu{\´i}lez, Jos{\´e} and Rodr{\´i}guez-Caballero, Emilio and Rousk, Kathrin and Sancho, Leopoldo G. and Scheidegger, Christoph and Seitz, Steffen and Van Stan, John T. and Veste, Maik and Weber, Bettina and Weston, David J.}, title = {A research agenda for non-vascular photoautotrophs under climate change}, series = {New Phytologist}, volume = {237 (2023)}, journal = {New Phytologist}, number = {5}, issn = {0028-646X}, doi = {10.1111/nph.18631}, pages = {1495 -- 1504}, abstract = {Non-vascular photoautotrophs (NVP), including bryophytes, lichens, terrestrial algae, and cyanobacteria, are increasingly recognized as being essential to ecosystem functioning in many regions of the world. Current research suggests that climate change may pose a substantial threat to NVP, but it is highly uncertain to what extent this will affect the associated ecosystem functions and services. Here, we propose a research agenda to address this urgent question, focusing on physiological and ecological processes that link NVP to ecosystem functions while also taking into account the substantial taxonomic diversity across multiple ecosystem types. Accordingly, we developed a new categorization scheme, based on microclimatic gradients, which simplifies the high physiological and morphological diversity of NVP and worldwide distribution with respect to several broad habitat types. We found that habitat-specific ecosystem functions of NVP will likely be substantially affected by climate change, and more quantitative process understanding is required on (1) potential for acclimation (2) response to elevated CO2 (3) role of the microbiome and (4) feedback to (micro)climate. We suggest an integrative approach of innovative, multi-method laboratory and field experiments and eco-physiological modelling, for which sustained scientific collaboration on NVP research will be essential.}, language = {en} } @misc{HowellTuckerGroteetal., author = {Howell, Armin and Tucker, Colin and Grote, Ed and Veste, Maik and Belnap, Jayne and Kast, Gerhard and Weber, Bettina and Reed, Sasha C.}, title = {Manufacturing Simple and Inexpensive Soil Surface Temperature and Gravimetric Water Content Sensors}, series = {Journal of Visualized Experiments}, volume = {154}, journal = {Journal of Visualized Experiments}, issn = {1940-087X}, doi = {10.3791/60308}, pages = {13}, abstract = {Quantifying temperature and moisture at the soil surface is essential for understanding how soil surface biota responds to changes in its environment. However, at the soil surface these variables are highly dynamic and standard sensors do not explicitly measure temperature or moisture in the upper few millimeters of the soil profile. This manuscript describes methods for manufacturing simple, inexpensive sensors that simultaneously measure the temperature and moisture of the upper 5 mm of the soil surface. In addition to sensor construction, steps for quality control, as well as for calibration for various substrates, are explained. The sensors incorporate a Type E thermocouple to measure temperature and assess soil moisture by measuring the resistance between two gold-plated metal probes at the end of the sensor at a depth of 5 mm. The methods presented here can be altered to customize probes for different depths or substrates. These sensors have been effective in a variety of environments and have endured months of heavy rains in tropical forests as well as intense solar radiation in deserts of the southwestern U.S. Results demonstrate the effectiveness of these sensors for evaluating warming, drying, and freezing of the soil surface in a global change experiment.}, language = {en} }