TY - JOUR A1 - Bizic, Mina A1 - Ionescu, Danny A1 - Karnatak, Rajat A1 - Musseau, Camille L. A1 - Onandia, Gabriela A1 - Berger, Stella A. A1 - Nejstgaard, Jens C. A1 - Lischeid, Gunnar A1 - Gessner, Mark O. A1 - Wollrab, Sabine A1 - Grossart, Hans-Peter T1 - Land-use type temporarily affects active pond community structure but not gene expression patterns JF - Molecular ecology N2 - Changes in land use and agricultural intensification threaten biodiversity and ecosystem functioning of small water bodies. We studied 67 kettle holes (KH) in an agricultural landscape in northeastern Germany using landscape-scale metatranscriptomics to understand the responses of active bacterial, archaeal and eukaryotic communities to land-use type. These KH are proxies of the millions of small standing water bodies of glacial origin spread across the northern hemisphere. Like other landscapes in Europe, the study area has been used for intensive agriculture since the 1950s. In contrast to a parallel environmental DNA study that suggests the homogenization of biodiversity across KH, conceivably resulting from long-lasting intensive agriculture, land-use type affected the structure of the active KH communities during spring crop fertilization, but not a month later. This effect was more pronounced for eukaryotes than for bacteria. In contrast, gene expression patterns did not differ between months or across land-use types, suggesting a high degree of functional redundancy across the KH communities. Variability in gene expression was best explained by active bacterial and eukaryotic community structures, suggesting that these changes in functioning are primarily driven by interactions between organisms. Our results indicate that influences of the surrounding landscape result in temporary changes in the activity of different community members. Thus, even in KH where biodiversity has been homogenized, communities continue to respond to land management. This potential needs to be considered when developing sustainable management options for restoration purposes and for successful mitigation of further biodiversity loss in agricultural landscapes. KW - agriculture KW - eRNA KW - land use KW - metacommunity KW - transcriptomics Y1 - 2022 U6 - https://doi.org/10.1111/mec.16348 SN - 0962-1083 SN - 1365-294X VL - 31 IS - 6 SP - 1716 EP - 1734 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Leong, Jia Xuan A1 - Raffeiner, Margot A1 - Spinti, Daniela A1 - Langin, Gautier A1 - Franz-Wachtel, Mirita A1 - Guzman, Andrew R. A1 - Kim, Jung-Gun A1 - Pandey, Pooja A1 - Minina, Alyona E. A1 - Macek, Boris A1 - Hafren, Anders A1 - Bozkurt, Tolga O. A1 - Mudgett, Mary Beth A1 - Börnke, Frederik A1 - Hofius, Daniel A1 - Uestuen, Suayib T1 - A bacterial effector counteracts host autophagy by promoting degradation of an autophagy component JF - The EMBO journal N2 - Beyond its role in cellular homeostasis, autophagy plays anti- and promicrobial roles in host-microbe interactions, both in animals and plants. One prominent role of antimicrobial autophagy is to degrade intracellular pathogens or microbial molecules, in a process termed xenophagy. Consequently, microbes evolved mechanisms to hijack or modulate autophagy to escape elimination. Although well-described in animals, the extent to which xenophagy contributes to plant-bacteria interactions remains unknown. Here, we provide evidence that Xanthomonas campestris pv. vesicatoria (Xcv) suppresses host autophagy by utilizing type-III effector XopL. XopL interacts with and degrades the autophagy component SH3P2 via its E3 ligase activity to promote infection. Intriguingly, XopL is targeted for degradation by defense-related selective autophagy mediated by NBR1/Joka2, revealing a complex antagonistic interplay between XopL and the host autophagy machinery. Our results implicate plant antimicrobial autophagy in the depletion of a bacterial virulence factor and unravel an unprecedented pathogen strategy to counteract defense-related autophagy in plant-bacteria interactions. KW - autophagy KW - effectors KW - immunity KW - ubiquitination KW - xenophagy Y1 - 2022 U6 - https://doi.org/10.15252/embj.2021110352 SN - 0261-4189 SN - 1460-2075 VL - 41 IS - 13 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Tolomeev, Aleksandr P. A1 - Dubovskaya, Olga P. A1 - Kirillin, Georgiy A1 - Buseva, Zhanna A1 - Kolmakova, Olesya A1 - Grossart, Hans-Peter A1 - Tang, Kam W. A1 - Gladyšev, Michail I. T1 - Degradation of dead cladoceran zooplankton and their contribution to organic carbon cycling in stratified lakes BT - field observation and model prediction JF - Journal of plankton research N2 - The contribution of dead zooplankton biomass to carbon cycle in aquatic ecosystems is practically unknown. Using abundance data of zooplankton in water column and dead zooplankton in sediment traps in Lake Stechlin, an ecological-mathematical model was developed to simulate the abundance and sinking of zooplankton carcasses and predict the related release of labile organic matter (LOM) into the water column. We found species-specific differences in mortality rate of the dominant zooplankton: Daphnia cucullata, Bosmina coregoni and Diaphanosoma brachyurum (0.008, 0.129 and 0.020 day(-1), respectively) and differences in their carcass sinking velocities in metalimnion (and hypolimnion): 2.1 (7.64), 14.0 (19.5) and 1.1 (5.9) m day(-1), respectively. Our model simulating formation and degradation processes of dead zooplankton predicted a bimodal distribution of the released LOM: epilimnic and metalimnic peaks of comparable intensity, ca. 1 mg DW m(-3) day(-1). Maximum degradation of carcasses up to ca. 1.7 mg DW m(-3) day(-1) occurred in the density gradient zone of metalimnion. LOM released from zooplankton carcasses into the surrounding water may stimulate microbial activity and facilitate microbial degradation of more refractory organic matter; therefore, dead zooplankton are expected to be an integral part of water column carbon source/sink dynamics in stratified lakes. KW - zooplankton carcasses KW - non-predatory mortality KW - sinking velocities KW - microbial degradation KW - Lake Stechlin KW - simulation modeling Y1 - 2022 U6 - https://doi.org/10.1093/plankt/fbac023 SN - 0142-7873 SN - 1464-3774 VL - 44 IS - 3 SP - 386 EP - 400 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Muntaha, Sidratul Nur A1 - Li, Xiaoping A1 - Compart, Julia A1 - Apriyanto, Ardha A1 - Fettke, Jörg T1 - Carbon pathways during transitory starch degradation in Arabidopsis differentially affect the starch granule number and morphology in the dpe2/phs1 mutant background JF - Plant physiology and biochemistry : an official journal of the Federation of European Societies of Plant Physiology N2 - The Arabidopsis knockout mutant lacking both the cytosolic disproportionating enzyme 2 (DPE2) and the plastidial phosphorylase (PHS1) had a dwarf-growth phenotype, a reduced and uneven distribution of starch within the plant rosettes, and a lower starch granule number per chloroplast under standard growth conditions. In contrast, a triple mutant impaired in starch degradation by its additional lack of the glucan, water dikinase (GWD) showed improved plant growth, a starch-excess phenotype, and a homogeneous starch distribution. Furthermore, the number of starch granules per chloroplast was increased and was similar to the wild type. We concluded that ongoing starch degradation is mainly responsible for the observed phenotype of dpe2/phs1. Next, we generated two further triple mutants lacking either the phosphoglucan, water dikinase (PWD), or the disproportionating enzyme 1 (DPE1) in the background of the double mutant. Analysis of the starch metabolism revealed that even minor ongoing starch degradation observed in dpe2/phs1/pwd maintained the double mutant phenotype. In contrast, an additional blockage in the glucose pathway of starch breakdown, as in dpe2/phs1/ dpe1, resulted in a nearly starch-free phenotype and massive chloroplast degradation. The characterized mutants were discussed in the context of starch granule formation. KW - Starch granules KW - Starch metabolism KW - Starch granule number per KW - chloroplast KW - Starch morphology KW - LCSM KW - Arabidopsis thaliana Y1 - 2022 U6 - https://doi.org/10.1016/j.plaphy.2022.03.033 SN - 0981-9428 SN - 1873-2690 VL - 180 SP - 35 EP - 41 PB - Elsevier CY - Paris ER - TY - JOUR A1 - Kamali, Bahareh A1 - Stella, Tommaso A1 - Berg-Mohnicke, Michael A1 - Pickert, Jürgen A1 - Groh, Jannis A1 - Nendel, Claas T1 - Improving the simulation of permanent grasslands across Germany by using multi-objective uncertainty-based calibration of plant-water dynamics JF - European journal of agronomy N2 - The dynamics of grassland ecosystems are highly complex due to multifaceted interactions among their soil, water, and vegetation components. Precise simulations of grassland productivity therefore rely on accurately estimating a variety of parameters that characterize different processes of these systems. This study applied three calibration schemes - a Single-Objective (SO-SUFI2), a Multi-Objective Pareto (MO-Pareto), and, a novel Uncertainty-Based Multi-Objective (MO-SUFI2) - to estimate the parameters of MONICA (Model for Nitrogen and Carbon Simulation) agro-ecosystem model in grassland ecosystems across Germany. The MO-Pareto model is based on a traditional Pareto optimality concept, while the MO-SUFI2 optimizes multiple target variables considering their level of prediction uncertainty. We used measurements of leaf area index, aboveground biomass, and soil moisture from experimental data at five sites with different intensities of cutting regimes (from two to five cutting events per season) to evaluate model performance. Both MO-Pareto and MO-SUFI2 outperformed SO-SUFI2 during calibration and validation. The comparison of the two MO approaches shows that they do not necessarily conflict with each other, but MO-SUFI2 provides complementary information for better estimations of model parameter uncertainty. We used the obtained parameter ranges to simulate grassland productivity across Germany under different cutting regimes and quantified the uncertainty associated with estimated productivity across regions. The results showed higher uncertainty in intensively managed grasslands compared to extensively managed grasslands, partially due to a lack of high-resolution input information concerning cutting dates. Furthermore, the additional information on the quantified uncertainty provided by our proposed MO-SUFI2 method adds deeper insights on confidence levels of estimated productivity. Benefiting from additional management data collected at high resolution and ground measurements on the composition of grassland species mixtures appear to be promising solutions to reduce uncertainty and increase model reliability. KW - intensively managed grasslands KW - extensively managed grasslands KW - grassland productivity KW - pareto optimality Y1 - 2022 U6 - https://doi.org/10.1016/j.eja.2022.126464 SN - 1161-0301 SN - 1873-7331 VL - 134 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Reinhard, Johanna E. A1 - Geißler, Katja A1 - Blaum, Niels T1 - Grass and ground dwelling beetle community responses to holistic and wildlife grazing management using a cross-fence comparison in Western Kalahari rangeland, Namibia JF - Journal of insect conservation : an international journal devoted to the conservation of insects and related invertebrates N2 - Savannahs are often branded by livestock grazing with resulting land degradation. Holistic management of livestock was proposed to contribute to biodiversity conservation by simulating native wildlife grazing behaviour. This study attempts the comparison of the impact of a holistic management regime to a wildlife grazing management regime on grass and ground-dwelling beetle species diversity on neighboring farms in Namibian rangeland. Results show that the response of biodiversity in species richness and composition to holistic management of livestock differs substantially from wildlife grazing with a positive impact. From a total of 39 identified species of ground-dwelling beetles (Coleoptera: Tenebrionidae, Carabidae) from 29 genera, eight species were found to be indicators for holistic management of livestock and three were found to be indicators for wildlife grazed rangeland. Observations suggest that holistic management of livestock may contribute to biodiversity conservation, but the differential effect of grazing management on species assemblages suggests that livestock grazing cannot replace native wildlife herbivory. Implications for insect conservation An adaptive management strategy such as holistic management used in this study shows the potential to support high beetle biodiversity. Holistic management of livestock thus aspects in favour for a sustainable form of grazing management for insect conservation even though it does not functionally replace grazing by native wildlife. KW - Beetle conservation KW - Land use management KW - Biodiversity KW - Insect conservation KW - Wildlife management Y1 - 2022 U6 - https://doi.org/10.1007/s10841-022-00410-6 SN - 1366-638X SN - 1572-9753 VL - 26 SP - 711 EP - 720 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Rosso, Pablo A1 - Nendel, Claas A1 - Gilardi, Nicolas A1 - Udroiu, Cosmin A1 - Chlebowski, Florent T1 - Processing of remote sensing information to retrieve leaf area index in barley BT - a comparison of methods JF - Precision agriculture N2 - Leaf area index (LAI) is a key variable in understanding and modeling crop-environment interactions. With the advent of increasingly higher spatial resolution satellites and sensors mounted on remotely piloted aircrafts (RPAs), the use of remote sensing in precision agriculture is becoming more common. Since also the availability of methods to retrieve LAI from image data have also drastically expanded, it is necessary to test simultaneously as many methods as possible to understand the advantages and disadvantages of each approach. Ground-based LAI data from three years of barley experiments were related to remote sensing information using vegetation indices (VI), machine learning (ML) and radiative transfer models (RTM), to assess the relative accuracy and efficacy of these methods. The optimized soil adjusted vegetation index and a modified version of the Weighted Difference Vegetation Index performed slightly better than any other retrieval method. However, all methods yielded coefficients of determination of around 0.7 to 0.9. The best performing machine learning algorithms achieved higher accuracies when four Sentinel-2 bands instead of 12 were used. Also, the good performance of VIs and the satisfactory performance of the 4-band RTM, strongly support the synergistic use of satellites and RPAs in precision agriculture. One of the methods used, Sen2-Agri, an open source ML-RTM-based operational system, was also able to accurately retrieve LAI, although it is restricted to Sentinel-2 and Landsat data. This study shows the benefits of testing simultaneously a broad range of retrieval methods to monitor crops for precision agriculture. KW - leaf area index KW - vegetation indices KW - machine learning KW - radiative transfer models Y1 - 2022 U6 - https://doi.org/10.1007/s11119-022-09893-4 SN - 1385-2256 SN - 1573-1618 VL - 23 IS - 4 SP - 1449 EP - 1472 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Kamali, Bahareh A1 - Lorite, Ignacio J. A1 - Webber, Heidi A. A1 - Rezaei, Ehsan Eyshi A1 - Gabaldon-Leal, Clara A1 - Nendel, Claas A1 - Siebert, Stefan A1 - Ramirez-Cuesta, Juan Miguel A1 - Ewert, Frank A1 - Ojeda, Jonathan J. T1 - Uncertainty in climate change impact studies for irrigated maize cropping systems in southern Spain JF - Scientific reports N2 - This study investigates the main drivers of uncertainties in simulated irrigated maize yield under historical conditions as well as scenarios of increased temperatures and altered irrigation water availability. Using APSIM, MONICA, and SIMPLACE crop models, we quantified the relative contributions of three irrigation water allocation strategies, three sowing dates, and three maize cultivars to the uncertainty in simulated yields. The water allocation strategies were derived from historical records of farmer's allocation patterns in drip-irrigation scheme of the Genil-Cabra region, Spain (2014-2017). By considering combinations of allocation strategies, the adjusted R-2 values (showing the degree of agreement between simulated and observed yields) increased by 29% compared to unrealistic assumptions of considering only near optimal or deficit irrigation scheduling. The factor decomposition analysis based on historic climate showed that irrigation strategies was the main driver of uncertainty in simulated yields (66%). However, under temperature increase scenarios, the contribution of crop model and cultivar choice to uncertainty in simulated yields were as important as irrigation strategy. This was partially due to different model structure in processes related to the temperature responses. Our study calls for including information on irrigation strategies conducted by farmers to reduce the uncertainty in simulated yields at field scale. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-08056-9 SN - 2045-2322 VL - 12 IS - 1 PB - Macmillan Publishers Limited, CY - London ER - TY - JOUR A1 - Stiegler, Jonas A1 - Lins, Alisa A1 - Dammhahn, Melanie A1 - Kramer-Schadt, Stephanie A1 - Ortmann, Sylvia A1 - Blaum, Niels T1 - Personality drives activity and space use in a mammalian herbivore JF - Movement Ecology N2 - Background Animal personality has emerged as a key concept in behavioral ecology. While many studies have demonstrated the influence of personality traits on behavioral patterns, its quantification, especially in wild animal populations, remains a challenge. Only a few studies have established a link between personality and recurring movements within home ranges, although these small-scale movements are of key importance for identifying ecological interactions and forming individual niches. In this regard, differences in space use among individuals might reflect different exploration styles between behavioral types along the shy-bold continuum. Methods We assessed among-individual differences in behavior in the European hare (Lepus europaeus), a characteristic mammalian herbivore in agricultural landscapes using a standardized box emergence test for captive and wild hares. We determined an individuals’ degree of boldness by measuring the latencies of behavioral responses in repeated emergence tests in captivity. During capture events of wild hares, we conducted a single emergence test and recorded behavioral responses proven to be stable over time in captive hares. Applying repeated novel environment tests in a near-natural enclosure, we further quantified aspects of exploration and activity in captive hares. Finally, we investigated whether and how this among-individual behavioral variation is related to general activity and space use in a wild hare population. Wild and captive hares were treated similarly and GPS-collared with internal accelerometers prior to release to the wild or the outdoor enclosure, respectively. General activity was quantified as overall dynamic body acceleration (ODBA) obtained from accelerometers. Finally, we tested whether boldness explained variation in (i) ODBA in both settings and (ii) variation in home ranges and core areas across different time scales of GPS-collared hares in a wild population. Results We found three behavioral responses to be consistent over time in captive hares. ODBA was positively related to boldness (i.e., short latencies to make first contact with the new environment) in both captive and wild hares. Space use in wild hares also varied with boldness, with shy individuals having smaller core areas and larger home ranges than bold conspecifics (yet in some of the parameter space, this association was just marginally significant). Conclusions Against our prediction, shy individuals occupied relatively large home ranges but with small core areas. We suggest that this space use pattern is due to them avoiding risky, and energy-demanding competition for valuable resources. Carefully validated, activity measurements (ODBA) from accelerometers provide a valuable tool to quantify aspects of animal personality along the shy-bold continuum remotely. Without directly observing—and possibly disturbing—focal individuals, this approach allows measuring variability in animal personality, especially in species that are difficult to assess with experiments. Considering that accelerometers are often already built into GPS units, we recommend activating them at least during the initial days of tracking to estimate individual variation in general activity and, if possible, match them with a simple novelty experiment. Furthermore, information on individual behavioral types will help to facilitate mechanistic understanding of processes that drive spatial and ecological dynamics in heterogeneous landscapes. KW - Animal personality KW - Movement ecology KW - Inter-individual differences KW - ODBA KW - Energy expenditure KW - European hare Y1 - 2022 U6 - https://doi.org/10.1186/s40462-022-00333-6 SN - 2051-3933 VL - 10 PB - BioMed Central (BMC), Springer Nature CY - London ER - TY - JOUR A1 - Hering, Robert A1 - Hauptfleisch, Morgan A1 - Jago, Mark A1 - Smith, Taylor A1 - Kramer-Schadt, Stephanie A1 - Stiegler, Jonas A1 - Blaum, Niels T1 - Don't stop me now: Managed fence gaps could allow migratory ungulates to track dynamic resources and reduce fence related energy loss JF - Frontiers in Ecology and Evolution N2 - In semi-arid environments characterized by erratic rainfall and scattered primary production, migratory movements are a key survival strategy of large herbivores to track resources over vast areas. Veterinary Cordon Fences (VCFs), intended to reduce wildlife-livestock disease transmission, fragment large parts of southern Africa and have limited the movements of large wild mammals for over 60 years. Consequently, wildlife-fence interactions are frequent and often result in perforations of the fence, mainly caused by elephants. Yet, we lack knowledge about at which times fences act as barriers, how fences directly alter the energy expenditure of native herbivores, and what the consequences of impermeability are. We studied 2-year ungulate movements in three common antelopes (springbok, kudu, eland) across a perforated part of Namibia's VCF separating a wildlife reserve and Etosha National Park using GPS telemetry, accelerometer measurements, and satellite imagery. We identified 2905 fence interaction events which we used to evaluate critical times of encounters and direct fence effects on energy expenditure. Using vegetation type-specific greenness dynamics, we quantified what animals gained in terms of high quality food resources from crossing the VCF. Our results show that the perforation of the VCF sustains herbivore-vegetation interactions in the savanna with its scattered resources. Fence permeability led to peaks in crossing numbers during the first flush of woody plants before the rain started. Kudu and eland often showed increased energy expenditure when crossing the fence. Energy expenditure was lowered during the frequent interactions of ungulates standing at the fence. We found no alteration of energy expenditure when springbok immediately found and crossed fence breaches. Our results indicate that constantly open gaps did not affect energy expenditure, while gaps with obstacles increased motion. Closing gaps may have confused ungulates and modified their intended movements. While browsing, sedentary kudu's use of space was less affected by the VCF; migratory, mixed-feeding springbok, and eland benefited from gaps by gaining forage quality and quantity after crossing. This highlights the importance of access to vast areas to allow ungulates to track vital vegetation patches. KW - veterinary cordon fence KW - ungulate KW - fence ecology KW - resource-tracking KW - energy expenditure KW - accelerometer KW - GPS KW - wildlife and habitat management Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2022.907079 SN - 2296-701X SP - 1 EP - 18 PB - Frontiers CY - Lausanne, Schweiz ER -