Biology subjects

Seipel, T.

Publications and source records attributed to Seipel, T..

4 recordsLinked to original sources

bioRxiv2024

Mountain roads across the globe significantly alter local soil microclimates

Mountain roads have repeatedly shown to host significantly different plant species communities compared to the adjacent natural vegetation. Besides the effect of propagule pressure, altered disturbance regime and soil processes, one of the reasons given for the strong influence of mountain roads on species distributions is a significantly altered microclimate in the roadside compared to the adjacent vegetation, a direct consequence of the altered disturbance regime. However, the microclimatic differences between roadside and natural vegetation have rarely been quantified, particularly lacking global analyses, hampering a better understanding of their importance for mountain biodiversity. In this study, we analysed in-situ measured soil temperatures along mountain roads in seven mountain regions across the globe, in order to assess the impact of mountain roads on a range of bioclimatic variables across the elevational gradient. Our results undeniably show the importance of roadsides as unique microhabitats, even in heterogeneous mountain environments. In most regions, roadside soils had warmer maxima (3.95 {+/-} 2.35{degrees}C warmer) and colder minima (0.85 {+/-} 1.11 {degrees}C colder) than the soil in the adjacent vegetation, with higher frost risks in winter. Therefore, we recommend future research to incorporate the notion that the local microclimates created by mountain roads could play a critical role in species redistributions in space and time.

ecology↗

bioRxiv2024

Darwin's Naturalization Conundrum explained by gradients of environmental stress and disturbance

Darwins Naturalization Conundrum (DNC) states that non-native species closely related to the native community are either more likely to succeed because shared adaptations help them overcome environmental filtering, or less likely to succeed because of strong competition with their native relatives. Despite extensive research, no general patterns have so far emerged. One reason may be that the relative importance of competition and environmental filtering depends on environmental conditions. To test this hypothesis, we conducted a global assessment of DNC examining patterns of phylogenetic relatedness of non-native plant species to the native community along gradients of elevation and anthropogenic disturbance in mountains. Phylogenetic distance of non-native to native species decreased with increasing elevation and in disturbed plant communities. Our results help resolve DNC by showing that the environmental context sets expectations for patterns of relatedness between non-native and native species and helps illuminate the ecological and evolutionary processes generating these patterns.

ecology↗

bioRxiv2020

Dryland cropping system, weed communities, and disease status modulate the effect of climate conditions on wheat soil bacterial communities.

Little knowledge exists on whether soil bacteria are impacted by cropping systems and disease status in current and predicted climate scenarios. We assessed the impact of soil moisture and temperature, weed communities, and disease status on soil bacterial communities across three cropping systems: conventional no-till (CNT) utilizing synthetic pesticides and herbicides, 2) USDA-certified tilled organic (OT), and 3) USDA-certified organic with sheep grazing (OG). Sampling date within the growing season, and associated soil temperature and moisture, exerted the greatest effect on bacterial communities, followed by cropping system, Wheat streak mosaic virus (WSMV) infection status, and weed community. Soil temperature was negatively associated with bacterial richness and evenness, while soil moisture was positively associated with bacterial richness and evenness. Both soil temperature and moisture altered soil bacterial community similarity. Inoculation with WSMV altered community similarity, and there was a date x virus interaction on bacterial richness in CNT and OT systems, as well as an interaction between WSMV x climate. In May and July, cropping system altered the effect of climate change on the bacterial community composition in hotter, and hotter and drier conditions not treated with WSMV, as compared to ambient conditions. In areas treated with WSMV, there were interactions between cropping system, sampling date, and climate conditions, indicating the effect of multiple stressors on bacterial communities in soil. Overall, this study indicates that predicted climate modifications as well as biological stressors play a fundamental role in the impact of cropping systems on soil bacterial communities. IMPORTANCEClimate change is affecting global moisture and temperature patterns and its impacts are predicted to worsen over time, posing progressively larger threats on food production. In the Northern Great Plains of the United States, climate change is forecasted to increase temperature and decrease precipitation during the summer, and is expected to negatively affect cereal crop production and pest management. In this study, temperature, soil moisture, weed communities, and disease status had interactive effects with cropping system on bacterial communities. As local climates continue to shift, so too will the dynamics of above- and below-ground associated bio-diversity which will impact food production and the need for more sustainable practices.

microbiology↗

bioRxiv2019

Rhizosphere bacterial communities of wheat vary across the growing season and among dryland farming systems.

Despite knowledge that seasonality and plant phenology impact soil microbiota, farming system effects on soil microbiota are not often evaluated across the growing season. We assessed the bacterial diversity in wheat rhizosphere soil through the spring and summer of 2016 in winter wheat (Triticum aestivium L.) in Montana, USA, from three contrasting farming systems: a chemically-managed no-tillage system, and two USDA-certified organic systems in their fourth year, one including tillage and one where sheep grazing partially offsets tillage frequency. Bacterial richness (range 605 - 1174 OTUs) and evenness (range 0.80 - 0.92) peaked in early June and dropped by late July (range 92 - 1190, 0.62-0.92, respectively), but was not different by farming systems. Organic tilled plots contained more putative nitrogen-fixing bacterial genera than the other two systems. Bacterial community similarities were significantly altered by sampling date, minimum and maximum temperature at sampling, bacterial abundance at date of sampling, total weed richness, and coverage of Taraxacum officinale, Lamium ampleuxicaule, and Thlaspi arvense. This study highlights that weed diversity, season, and farming management system all influence rhizosphere soil microbial communities. Local environmental conditions will strongly affect any practical applications aimed at improving soil diversity and functionality, especially in semi-arid regions where abiotic stress and seasonal variability in temperature and water availability drive primary production.

microbiology↗