Density‐dependent species interactions modulate alpine treeline shifts

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(4)

Published: April 1, 2024

Abstract Species interactions such as facilitation and competition play a crucial role in driving species range shifts. However, density dependence key feature of these processes has received little attention both empirical modelling studies. Herein, we used novel, individual‐based treeline model informed by rich situ observations to quantify the contribution density‐dependent alpine dynamics, an iconic biome boundary recognized indicator global warming. We found that dominate dense versus sparse vegetation scenarios respectively. The optimal balance between two effects was identified at intermediate thickness where elevation highest. Furthermore, shift rates decreased sharply with associated transition from positive negative interactions. thus postulate must be considered when dynamics avoid inadequate predictions its responses climate

Language: Английский

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Competition for time: Evidence for an overlooked, diversity‐maintaining competitive mechanism

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(3)

Published: March 1, 2024

Abstract Understanding how diversity is maintained in plant communities requires that we first understand the mechanisms of competition for limiting resources. In ecology, there an underappreciated but fundamental distinction between systems which depletion resources reduces growth rates competitors and resource time available to grow, a mechanism call ‘competition time’. Importantly, modern community ecology our framing coexistence problem are built on implicit assumption rate. However, recent theoretical work suggests may be predominant competitive broad array natural communities, significant advance given when species compete time, diversity‐maintaining trade‐offs emerge organically. this study, introduce conceptually using simple model interacting species. Then, perform experiment Mediterranean annual grassland determine whether important field system. Indeed, find respond increased through reductions their lifespan rather than rate growth. total, study overlooked as biodiversity maintenance.

Language: Английский

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Plant growth strategies and microbial contributions to ecosystem nitrogen retention along a soil acidification gradient

Ecology, Journal Year: 2025, Volume and Issue: 106(1)

Published: Jan. 1, 2025

Abstract Nitrogen (N) retention is a critical ecosystem function associated with sustainable N supply. Lack of experimental evidence limits our understanding how grassland can vary soil acidification. A 15 N‐labeling experiment was conducted for 2 years to quantify by pathways and plant functional groups across soil‐acidification gradient in meadow. The added the mainly intercepted (up 87.3%). Within soil, recovery ammonium, dissolved organic N, microbial biomass, amino sugars (a proxy necromass) represented approximately 46% soil‐retained N. these fractions increased acidification, highlighting complexity transformations that affect retention. Plant N‐retention sedges, decreased forbs, unaffected grasses reflecting their divergent associations mycorrhizas sensitivities Soil biomass key variable delineating retention, while sedges were resulting clear trade‐off competition between two compartments. Overall, acidification might curb losses strengthening shifting among different growth strategies.

Language: Английский

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Complementarity of Fine Roots and Ectomycorrhizal Fungi in Nitrogen Acquisition Along a Gradient of Intraspecific Competition Intensity

Plant Cell & Environment, Journal Year: 2025, Volume and Issue: unknown

Published: March 21, 2025

Plant roots can detect and react to the presence of competitors' roots. Intraspecific competition usually constrains root proliferation minimize overlap systems between competitors, especially in resource-impoverished environments. However, it remains largely unclear whether how this decline nutrient-scavenging capacity be complemented by other nutrient-acquisition strategies. Here, we leveraged 25 41-year-old Pinus Sylvestris var. mongolica monocultures with stand densities ranging from 350 1500 trees per hectare, reflecting a gradient intraspecific intensity. In these stands, measured variables ecosystem nitrogen (N) status, needle N resorption efficiency, nine morphological, physiological mycorrhizal traits. Results showed that increasing decreased soil transformation rates carbon-:N-acquisition enzyme ratios, indicating an degree deficiency. High-density stands had lower length density than low-density implying intense causing segregation. Conversely, was positively correlated relative abundance ectomycorrhizal fungi (EMF) genetic potential produce class II peroxidases. Collectively, findings highlight plant-available may account for segregation under suggest complementarity fine EMF nutrient acquisition at level.

Language: Английский

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Investigating the impacts of airborne dust on herbicide performance on Amaranthus retroflexus

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Feb. 15, 2024

Abstract Dust pollution poses environmental hazards, affecting agriculture through reduced sunlight exposure, photosynthesis, crop yields, and food security. This study explores the interference of dust on herbicide efficacy to control weeds in a semi-arid region. In factorial experiment conducted 2019 replicated 2020, interaction various applications, including bentazon, sulfosulfuron, tribenuron-methyl, aminopyralid + florasulam, foramsulfuron iodosulfuron thiencarbazone, 2,4-D MCPA, acetochlor, controlling Amaranthus retroflexus L. were assessed. induced 9.2% reduction total chlorophyll content A. , while application independently led 67.5% decrease. Contrary expectations, herbicides performed better dust, except which caused 28% drop plant height 29% decrease biomass compared non-dust conditions. Both exerted suppressive effects retroflexus's leaf stem weights overall biomass. Despite presence, tribenuron-methyl (95.8%), florasulam (95.7%), sulfosulfuron (96.5%), thiencarbazone (97.8%) effectively controlled retroflexus. These findings indicate that dust's effect is herbicide-dependent but generally increased amplified .

Language: Английский

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Fluctuation-dependent coexistence of stage-structured species

The American Naturalist, Journal Year: 2024, Volume and Issue: 205(3), P. 327 - 341

Published: Oct. 2, 2024

AbstractModern coexistence theory is a dominant framework for understanding how environmental fluctuations promote species coexistence. However, assessing fluctuation-dependent mechanisms of in empirical systems-in which have diverse life histories and environment-competition relationships-has remained challenging many ecologists. To help empiricists theoreticians alike build intuition the role across systems environments, we explore two stage-structured histories-perennial seedbanking annuals-differ competition with nonseedbanking annual three scenarios. Our scenarios delineate partition resources within among years whether most intense during favorable or unfavorable periods. We use this work to link differences vital rates interaction strengths patterns Fluctuation-dependent can be equally important perennial an adult "storage" stage as annuals. outcomes differentiate between these strategies based on they experience stronger weaker environments. This sets applying partitioning frameworks mixed stage-structure communities, facilitating variation drives dynamics broader range systems.

Language: Английский

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Competitors alter selection on alpine plants exposed to experimental climate change

Evolution Letters, Journal Year: 2023, Volume and Issue: 8(1), P. 114 - 127

Published: Dec. 28, 2023

Abstract Investigating how climate change alters selection regimes is a crucial step toward understanding the potential of populations to evolve in face changing conditions. Previous studies have mainly focused on directly influences selection, while role species’ interactions has received little attention. Here, we used transplant experiment along an elevation gradient estimate warming and competitive lead shifts directional phenotypic morphology phenology four alpine plants. We found that generally imposed novel with largest acting specific leaf area flowering time across species. Competitors instead weakened traits was by warming. Weakened or absent presence competitors largely associated suppression absolute means variation fitness. Our results suggest although can impose strong within communities might act limit thereby stymie evolutionary responses plants facing change.

Language: Английский

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Individual vital rates respond differently to local‐scale environmental variation and neighbour removal

Journal of Ecology, Journal Year: 2024, Volume and Issue: 112(6), P. 1369 - 1382

Published: April 12, 2024

Abstract Understanding how plant fitness varies along natural gradients is critical for predicting responses to environmental change. However, individual vital rates are often used as proxies without knowing other vary the same gradients. We investigated canopy cover, plant–plant interactions, water availability and soil properties influenced emergence, survival, seed production population growth of eight annual species in semi‐arid Western Australia. sowed seeds into sun‐exposed shaded blocks across a reserve, removed all neighbouring plants from half interaction neighbourhoods, rainout shelters reduce increase precipitation relative ambient plots. Canopy cover had strong negative effects on but few direct impacts rates. Direct competitive survival were rare, although evident rate 3/8 species. Competition was stronger open than plots also interacted with watering treatment influence species, alone species' found only positive significant correlations between pairs rates, far more frequently correlated emergence. Synthesis . Our study illustrates that can respond local‐scale variation different ways likely not driven by life history trade‐offs. caution against using emergence proxy emphasise no single reliable overall. Interactions among abiotic biotic factors important drivers some highlighting need account interactions when

Language: Английский

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Environmental gradients mediate dispersal evolution during biological invasions

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(7)

Published: July 1, 2024

Abstract Rapid evolution of increased dispersal at the edge a range expansion can accelerate invasions. However, populations expanding across environmental gradients often face challenging environments that reduce fitness dispersing individuals. We used an eco‐evolutionary model to explore how influence and, in turn, modulate speed and predictability invasion. Environmental opposed during invasion, even leading reduced along steeper gradients. Counterintuitively, could allow for faster by minimizing maladaptive gene flow facilitating adaptation. While homogenous landscapes both mean variance speed, these increases were greatly dampened illustrate our model's potential application prediction management invasions parameterizing it with data from recent invertebrate expansion. Overall, we find strongly effect on invasion trajectories.

Language: Английский

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Niche Theory and Species Range Limits along Elevational Gradients: Perspectives and Future Directions

Annual Review of Ecology Evolution and Systematics, Journal Year: 2024, Volume and Issue: 55(1), P. 449 - 469

Published: Aug. 14, 2024

Despite two centuries of research, the mechanisms underlying formation species’ elevational range limits remain poorly understood. The climatic variability hypothesis highlights role conditions in shaping thermal tolerance and distribution ranges, while species interactions–abiotic stress underscores relative importance biotic factors abiotic along environmental gradients. We emphasize Darwin's perspective on ubiquity interspecific competition across gradients understanding how climate modulates interactions to shape distributions. Niche theory provides a comprehensive framework, combined with empirical explore influence traits, leading context-dependent that constrain In particular, application concept environmentally weighted performance can further elucidate these complex ecological mechanisms. Future research should integrate multiple approaches, including field laboratory manipulative experiments, theoretical modeling, interdisciplinary collaboration, improve our distributions mountain regions inform biodiversity conservation strategies face rapid change.

Language: Английский

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