Biology subjects

Garbowski, M.

Publications and source records attributed to Garbowski, M..

3 recordsLinked to original sources

bioRxiv2026

Nutrient enrichment and herbivore exclusion disrupt the climate-driven balance between C3 and C4 plants in grasslands

The distribution of plants with different photosynthetic pathways is strongly structured by climate, with C3 plants favoured in cooler temperate regions and C4 plants in hotter, high-light conditions. The relative abundance of C3 and C4 plants across the world has cascading impacts on local food webs, decomposition, productivity and other vital ecosystem processes. Human impacts, including climate change, changes to herbivore assemblages, and increased nutrient availability, are shifting the optimal conditions for important C3 and C4-dominated ecosystems and crops. Using 3,184 plot-level observations from 112 sites across six continents, we reveal how chronic nutrient enrichment disrupts the climate-driven balance between C3 and C4 plants in grasslands. We found that, consistent with expectations, the global distribution of C4 plants was strongly related to climate. However, experimental nutrient addition reduced the relative cover of C4 species, with the strongest declines found when nitrogen and phosphorus were added together. Herbivore exclusion had no consistent effect on C4 plants. Our results provide global experimental evidence that elevated nutrients, particularly nitrogen, alter competitive outcomes among plant functional types to suppress C4 grasses, even in climatically optimal conditions. This has major implications for predicting vegetation responses to global change, with consequences for carbon cycling, primary productivity, herbivore dynamics, and food security.

ecology↗

bioRxiv2026

Wildfire, restoration, and post-wildfire rehabilitation effects on wind erosion in the Great Basin

Restoration of degraded areas and post-disturbance rehabilitation after wildfire encompass critical approaches for reducing and reversing impacts of wind erosion and sand and dust storms (SDS). However, the broad outcomes of dryland restoration and rehabilitation for wind erosion and SDS remain underexplored. Wind erosion is an emerging issue in the Great Basin of the western United States, exacerbated by invasive annual grasses and associated wildfire. Here, we assess potential wind erosion and SDS responses to wildfire, restoration, and post-wildfire rehabilitation treatments at the regional scale in the Great Basin. We used 13 years of rangeland monitoring data, the Aeolian EROsion model, and the Land Treatment Digital Library to produce counterfactual model-predictions to estimate treatment effects. Our results revealed reductions in aeolian sediment fluxes (Ln Q < 0 g m-1 d-1) across wildfire-affected regions (mean {+/-} SE: -0.070 {+/-} 0.077 Ln Q), restoration treatments in unburned areas (range: -0.867 {+/-} 0.398 to 0.480 {+/-} 0.253 Ln Q), and post-wildfire rehabilitation (range: -0.821 {+/-} 0.183 to 1.278 {+/-} 0.909 Ln Q). In particular, aerial seeding and soil disturbance restoration treatments, and post-wildfire closure-treatments had higher perennial grass cover and the most decreased Ln Q compared to untreated controls. These results represent an important regional scale assessment of wind erosion responses to restoration and post-wildfire rehabilitation. Our findings underscore the application of integrating wind erosion and SDS mitigation into restoration and post-disturbance rehabilitation programs to provide land managers with strategies to reduce land degradation while fostering ecosystem resilience.

ecology↗

bioRxiv2022

Temperature seasonality and nutrient enrichment drive intra-annual community turnover in global grasslands

In many grasslands, species with specific traits occupy unique temporal positions within communities. Such intra-annual segregation is predicted to be greatest in systems with high intra-annual climate variability because fluctuating environmental conditions provide opportunities for temporal niche partitioning among species. However, because most studies on intra-annual community dynamics have been conducted at individual sites, relationships between intra-annual climate variability and seasonal community dynamics at global scales have not yet been identified. Furthermore, the same characteristics that promote species-specific responses to fluctuations in environmental conditions may also drive species-specific responses to global change drivers such as eutrophication. Research provides evidence that eutrophication alters inter-annual plant community dynamics yet understanding of how it alters intra-annual dynamics remains limited. We used early-season and late-season compositional data collected from 10 grassland sites around the world to ask how intra-annual variability in precipitation and temperature as well as nutrient enrichment shape intra-annual species segregation, or seasonal {beta}-diversity, in plant communities. We also assessed whether changes in the abundances of specific functional groups including annual forbs, perennial forbs, C3 and C4 graminoids, and legumes underpin compositional differences between early- and late-season communities and treatments. We found that intra-annual temperature variability and seasonal {beta}-diversity were positively related but observed no relationship between intra-annual precipitation variability and seasonal {beta}-diversity. This suggests that positive relationships between -diversity and intra-annual temperature variability identified in earlier studies may be underpinned by the positive influence of intra-annual temperature variability on temporal segregation of species within growing seasons. We found that nutrient enrichment increased seasonal {beta}-diversity via increased turnover of species between early- and late-season communities. This finding mirrors patterns observed at inter-annual scales and suggests fertilization can alter compositional dynamics via similar mechanisms at varied temporal scales. Finally, fertilization reduced the abundance of C4 graminoids and legumes and eliminated intra-annual differences in these groups. In contrast, fertilization resulted in intra-annual differences in C3 graminoids which were not observed in control conditions, and increased abundance of C3 graminoids and annual forbs overall. Our study provides new insight into how intra-annual climate variability and nutrient enrichment influence biodiversity and seasonal dynamics in global grasslands.

ecology↗