Temporal changes in the dominance of tree functional traits, but no changes in species diversity during woody plant encroachment in a Brazilian savanna

Journal of Vegetation Science, Journal Year: 2023, Volume and Issue: 34(2)

Published: Feb. 27, 2023

Abstract Questions : Woody encroachment in savannas has been associated with changing taxonomic composition and ecosystem function. Interestingly, there is little understanding of how impacts plant functional diversity those changes relate to demography, a crucial mediator between Location Southeastern Brazil. Methods: Using landscape scale fire suppression experiment diverse Brazilian savanna, we quantify change species over seven years impacted vegetative reproductive tree as determined by new recruits, dead surviving trees. Results: Over years, above‐ground biomass increased 15%, while total richness did not change. Despite minor changes, remained overall similar (82%), few contributing significantly plot dissimilarity time. There were small traits, where the community‐weighted mean maximum height (↑ 2.1%) specific leaf area 5.3%), decreased wood density (↓ 1.3%) bark thickness 9.4%). Changes traits larger than an increase prevalence monoecy 32.6%), dioecy 44.2%), large seeds 20.3%), animal‐mediated seed dispersal 4.9%) pollination very insects 45.5%), decrease hermaphroditism 9%), (6.8%) (12.5%). The mainly driven characters (SLA) appeared largely loss trees possessing traits. Conclusions: Encroachment leads that are likely increasing vulnerability drought. Further, compositional observed appear drive marked indicating dependence on animals for reproduction. Understanding post‐hoc era widespread pervasive fundamental reconciling functions such nutrient cycling services open life‐history strategies. Among savannas, remains urgent need understand relationships woody cover function determine thresholds promoting resilient savanna ecosystems.

Language: Английский

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Variability in leaf traits reveals contrasting strategies between forest and grassland woody communities across southern Brazil

Flora, Journal Year: 2023, Volume and Issue: 305, P. 152340 - 152340

Published: June 28, 2023

Language: Английский

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Coordination of bark and wood traits underlies forest‐to‐savanna evolutionary transitions

Journal of Biogeography, Journal Year: 2024, Volume and Issue: 51(9), P. 1801 - 1813

Published: April 30, 2024

Abstract Aim To test the hypothesis that adaptive shifts leading to assembly of tropical savannas involved coordination between bark and wood traits understand underlying mechanisms. Location Tropical South America. Taxon Angiosperms (woody). Methods We compiled data on three (total, inner outer relative thickness), density, maximum height, five secondary xylem species' habitat information (light environment, climate, soil fire history) for Neotropical savanna, forest generalist species (biome groups). tested pairwise multivariate associations among across if biome group conditions explained positions along resulting strategy axes. Results Traits covaried four different The first axis was consistent with a trade‐off (thick barks) shade tolerance (low diameter ratio, high vessel density) contributed differentiate groups according preference shaded environments. Forest also differed from savanna in separate by being more resource acquisitive. Maximum height density did not strongly thickness, although negatively thickness. Preference main driver variation two principal axes, but temperature, sand content differences plant stature species. Main Conclusions Allocation is constrained trade‐offs wood, opposing shade‐tolerant acquisitive fire‐resistant conservative Rather than single axis, axes are necessary functional Because these controlled light availability, associated tend covary space time,

Language: Английский

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Responses of plant species to mechanical soil disturbance in fire-dependent pine communities of the North American Coastal Plain - a synthesis

Forest Ecology and Management, Journal Year: 2024, Volume and Issue: 565, P. 122018 - 122018

Published: June 12, 2024

Language: Английский

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Drivers of tree community assembly during tropical forest post-fire succession in anthropogenic savannas

Perspectives in Plant Ecology Evolution and Systematics, Journal Year: 2021, Volume and Issue: 52, P. 125630 - 125630

Published: July 30, 2021

Language: Английский

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Shade drives plant community changes of ground‐layer savanna vegetation: Short‐term changes under an experimental approach

Journal of Vegetation Science, Journal Year: 2022, Volume and Issue: 33(2)

Published: Feb. 5, 2022

Abstract Aim Woody‐plant encroachment is a reality in many savannas worldwide, leading to become replaced by forest ecosystems. As tree density and cover increase, increased shade litter deposition may suppress the savanna's community of low‐lying plants. By using field manipulation, we tested shading effects, alone combination, on ground‐layer plant community. We investigated how changes these environmental factors affect composition, structure, above‐ground biomass species‐rich Neotropical savanna. Location Savanna patches Cerrado, southeastern Brazil. Methods Annual surveys herbaceous–shrub layer three‐year manipulation experiment examining deposition. Results Shade negatively affected all evaluated parameters, while addition had only minor effects. The largest losses richness, density, occurred forbs grasses. Increased resulted sharp decrease monocots. Conclusions Our results show that light strong filter for reductions grass under treatments likely altered ecosystem functioning. Woody can thus be considered represent process alter structure functioning savannas. Management interventions should therefore taken prevent woody or mitigate its harmful effects savanna biodiversity

Language: Английский

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Coastal Forest in Eastern Southern Africa has Savanna Bush-clump Origins

Ecosystems, Journal Year: 2023, Volume and Issue: 26(5), P. 1033 - 1046

Published: Jan. 9, 2023

Language: Английский

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Canopy plant composition and structure of Cape subtropical dune thicket are predicted by the levels of fire exposure

PeerJ, Journal Year: 2022, Volume and Issue: 10, P. e14310 - e14310

Published: Nov. 8, 2022

Background The subtropical dune thicket (hereafter “dune thicket”) of the Cape Floristic Region experiences a wide range fire exposure throughout landscape, unlike other dry rainforest formations that rarely experience fire. We sought to determine how influences species composition and architectural thicket. Methods used multivariate analysis diversity indices based on cover abundance describe composition, guild structure sites subject different levels exposure, namely low (fire return interval >100 years), moderate 50–100 high 10–50 years). Results diversity, canopy were strongly influenced by level such each was associated with well-circumscribed vegetation unit. Dune thickets comprises floristically distinct, forest characterized shrubs one-to-few upright stems (ca. 4–8 m tall) relatively small spread (vertical growers). Of 25 in this unit, 40% restricted it. had highest lateral spreaders, which are multi-stemmed 3–6 large lower stature than vertical growers. None 17 found unit hedge-forming shrubs, these being 0.6–1.4 tall), numerous shoots arising from an extensive system below-ground stems. 20 Multivariate identified three floristic units corresponding regimes. Compositional structure, terms guilds, most distinctive for while showed greatest compositional overlap units. Conclusion Fire profoundly Region. In prolonged absence fire, is invaded vertical-growing overtop outcompete multi-stemmed, laterally-spreading dominate community. Regular selects traits enable rapidly compete post-fire via prolific production resprouts basal buds below- above-ground. trade-off plant height constrained, as proportionately more resources allocated biomass.

Language: Английский

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Floristic patterns among phytogeographical domains: unraveling the complexity of Brazilian transitions

Folia Geobotanica, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 4, 2024

Language: Английский

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An enemy's enemy is an ally: Competitive indirect interactions mediate coexistence of trees, grasses, and subshrubs in neotropical savanna

Biotropica, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

Abstract Savannas are complex ecosystems where multiple growth forms, including grasses, trees, and subshrubs, coexist through intricate ecological interactions. Understanding the mechanisms that promote this coexistence is key to conserving savanna biodiversity. This study investigated effects of grass competition on survival trees as well interactions between these two forms. Using three species we conducted a greenhouse experiment assess how subshrubs influenced by presence grass. We found significantly reduced tree seedlings, while were unaffected. When competed directly, subshrub biomass was reduced, but only in absence Tree seedling not affected negatively impacted subshrubs. Both root stem competition; however, effect mitigated when simultaneously. These results indicate compete together, intensity promoting contributing balance forms ecosystems. While fire an important factor dynamics, our emphasizes critical role maintaining balance. Future studies should explore interact further understanding biodiversity ecosystem function Neotropical savannas. Portuguese available with online material.

Language: Английский

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