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  1. Article ; Online: Leaf size and thickness are related to frost damage in ground layer species of Neotropical savannas

    de Antonio, Ariadne Cristina / Scalon, Marina Corrêa / Rossatto, Davi Rodrigo

    Flora. 2023 Feb., v. 299 p.152208-

    2023  

    Abstract: Savannas in southeastern Brazil are frequently exposed to frost events, causing the death of leaves and branches in many woody and herbaceous species. Frost events are frequent in these regions, with one relatively stronger than usual event every 5 years. ...

    Abstract Savannas in southeastern Brazil are frequently exposed to frost events, causing the death of leaves and branches in many woody and herbaceous species. Frost events are frequent in these regions, with one relatively stronger than usual event every 5 years. Our experimental site at São Paulo State, Southeastern Brazil, was affected by strong frost events during June–July 2021, when temperatures reached -4 °C, causing aboveground dieback in most ground layer species, although we observed some species were not affected and maintained a fully green canopy. We used this opportunistic frost event to study and report these damages and measured leaf traits that could explain our observations, as well as point directions to ecological understanding of frost on savanna vegetation. We measured morphological leaf traits such as leaf shape (width, length, width to length ratio), leaf area, specific leaf area and leaf thickness, and we also quantified canopy and leaf damage in 17 species (5 non-affected by frost and 12 that were visually affected). We found that species with larger and thicker leaves were more prone to leaf and canopy damage (70–100% of damage) than those with smaller and thinner leaves (0% damage). These results suggest that leaf morphology may provide resistance against frost and could ultimately act as a filter favoring species that can support extreme frost events, if those became more frequent and stronger under future climatic changes.
    Keywords Neotropics ; canopy ; death ; dieback ; flora ; frost ; frost injury ; herbaceous plants ; leaf area ; leaf morphology ; leaf thickness ; leaves ; savannas ; specific leaf area ; Brazil ; Cerrado ; Climate change ; Disturbance ; Frost resistance ; Leaf traits
    Language English
    Dates of publication 2023-02
    Publishing place Elsevier GmbH
    Document type Article ; Online
    ZDB-ID 5580-3
    ISSN 0367-2530 ; 0373-6490
    ISSN 0367-2530 ; 0373-6490
    DOI 10.1016/j.flora.2022.152208
    Database NAL-Catalogue (AGRICOLA)

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  2. Article: Why woody plant modularity through time and space must be integrated in fire research?

    Chiminazzo, Marco Antonio / Charles-Dominique, Tristan / Rossatto, Davi Rodrigo / Bombo, Aline Bertolosi / Fidelis, Alessandra

    AoB PLANTS

    2023  Volume 15, Issue 3, Page(s) plad029

    Abstract: Different ecosystems evolved and are maintained by fire, with their vegetation hosting species with a wide diversity of persistence strategies allowing them to insulate their body and resprout new branches after fire disturbance. Changes in fire regime ... ...

    Abstract Different ecosystems evolved and are maintained by fire, with their vegetation hosting species with a wide diversity of persistence strategies allowing them to insulate their body and resprout new branches after fire disturbance. Changes in fire regime are predicted due to climate change, either by promoting more frequent and/or severe fires or by reducing the number of fire events due to the limitation of fuel load. Predicting the future of fire-driven ecosystems is a complex task as species' survival depends on many factors that vary in space and time. Since plants are constantly experiencing new environments as they grow through meristem development, woody plant modularity, modules morpho-physiological aspects and their integration should be considered when investigating species strategies in fire-prone ecosystems: according to their position and their tissue composition, plants' modules experience fire differently and will contribute differently to other modules and the whole plant survival, with consequences cascading over the overall vegetation structure. Growth modules may hold the key to understanding how fast plants can get protected from fire, ultimately helping us to predict which species will persist across changing fire regimes. We present an empirical example showing how different fire-return intervals translate into distinct pressures on the timing, protection and location of modules, and discuss how these can translate into modifications in the vegetation structure due to climate change.
    Language English
    Publishing date 2023-05-23
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 2555823-7
    ISSN 2041-2851
    ISSN 2041-2851
    DOI 10.1093/aobpla/plad029
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Ground layer Cerrado plants sustain higher maximum photosynthetic rates after medium-term fire events

    Scalon, Marina Corrêa / Rossatto, Davi Rodrigo

    Flora. 2021 Dec., v. 285

    2021  

    Abstract: Fire is one of the most important factors driving community assembly and ecosystem functioning in tropical savannas. However, few studies have evaluated the physiological responses of ground layer plant communities to fire disturbance. Here we used ... ...

    Abstract Fire is one of the most important factors driving community assembly and ecosystem functioning in tropical savannas. However, few studies have evaluated the physiological responses of ground layer plant communities to fire disturbance. Here we used different fire regimes to investigate possible changes in leaf maximum gas exchange (Aₘₐₓ and gₛ) and leaf nutritional content (N, P, K, Ca and Mg) among different plant growth forms in savanna ground layer communities. We compared responses of ground layer plant communities under two different fire regimes: (1) no recent fire occurrence; and (2) two recurrent fire events in the last 20 years. We estimated canopy cover, soil chemical properties and species abundance on burned and unburned plots in order to calculate abundance-weighted species average trait values for gas exchange and leaf nutrient content. We found that burned plots exhibited lower canopy cover and soil organic matter content, and an overall higher soil macronutrients availability compared to unburned plots. These environmental differences clearly influenced the ground layer plant communities, which depicted higher Aₘₐₓ and gₛ in burned areas regardless of growth form. We found no significant differences among leaf nutrient traits, except for a lower Mg concentration in the burned site species. Our results support the hypothesis that distinct fire regimes select for a different set of leaf functional traits, with fire occurrence acting as an important driver increasing the maximum photosynthetic rate on the ground layer. While nutrient use seems not to be affected by medium-term recurrent fires, physiological plasticity on carbon and water use processes in response to changes in resource availability can promote the persistence of savanna species under frequent fire.
    Keywords canopy ; carbon ; cerrado ; ecosystems ; flora ; gas exchange ; leaves ; nutrient content ; photosynthesis ; physiological state ; plant growth ; savannas ; soil nutrients ; soil organic matter ; species abundance
    Language English
    Dates of publication 2021-12
    Publishing place Elsevier GmbH
    Document type Article
    ZDB-ID 5580-3
    ISSN 0367-2530 ; 0373-6490
    ISSN 0367-2530 ; 0373-6490
    DOI 10.1016/j.flora.2021.151962
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: Leaves of neotropical savanna tree species are more heat-tolerant than leaves of semi-deciduous forest species

    da Silva, Bianca Helena Porfírio / Rossatto, Davi Rodrigo

    Theoretical and Experimental Plant Physiology. 2022 June, v. 34, no. 2

    2022  

    Abstract: Increases of air temperature due to global warming suggest that plants could be exposed to temperatures above their optimum range for performing specific physiological functions in the future. Declines in carbon exchange rates would lead to significant ... ...

    Abstract Increases of air temperature due to global warming suggest that plants could be exposed to temperatures above their optimum range for performing specific physiological functions in the future. Declines in carbon exchange rates would lead to significant decreases in species performance, particularly in those lacking traits associated to heat tolerance. Savannas and semi-deciduous forests are ecosystems with high biological diversity, scattered throughout the Neotropical landscape, and very dynamic areas controlled by species traits. Significant increases in air temperatures can affect such areas if plant species of these forests lack heat tolerance. We performed heat tolerance assays to obtain T₅₀ values of the photosystem II (PSII) of 30 Neotropical tree species from a savanna (15 species) and a semi-deciduous forest (15 species). Our goal was to test whether the typical savanna species are more heat-tolerant than semi-deciduous forest species. We also assessed if T₅₀ was correlated with leaf morphological traits such as specific leaf area and leaf thickness. We found savanna tree leaves with lower specific leaf area, higher thickness, and higher T₅₀ values than semi-deciduous forest plants (49.36 °C vs. 47.65 °C, respectively). Specific leaf area was negatively correlated to T₅₀ values. Our findings suggest that semi-deciduous forest species would be more affected by temperature increases than savanna species. Whereas species traits play an important role in the dynamics of forest–savanna areas, savanna species would be favored under warmer temperatures.
    Keywords Neotropics ; air ; air temperature ; biodiversity ; carbon ; forests ; heat tolerance ; landscapes ; leaf thickness ; leaves ; photosystem II ; plant physiology ; savannas ; specific leaf area ; trees
    Language English
    Dates of publication 2022-06
    Size p. 227-237.
    Publishing place Springer International Publishing
    Document type Article
    ISSN 2197-0025
    DOI 10.1007/s40626-022-00244-2
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: The role of leaf cutting and fire on extrafloral nectaries and nectar production in Stryphnodendron adstringens (Fabaceae, Mimosoideae) plants

    Delgado, Marina Neves / de Morais, Helena Castanheira / Rossatto, Davi Rodrigo

    Plant species biology. 2022 July, v. 37, no. 4

    2022  

    Abstract: Herbivory pressure is an important ecological aspect to determine quantitative variation in plant defenses, such as the number of extrafloral nectaries (EFNs) and their nectar amount and quality. Extrafloral nectaries can attract ants, which can be ... ...

    Abstract Herbivory pressure is an important ecological aspect to determine quantitative variation in plant defenses, such as the number of extrafloral nectaries (EFNs) and their nectar amount and quality. Extrafloral nectaries can attract ants, which can be considered a type of induced plant defense. Besides, plants tend to invest more in defense when they are more vulnerable to herbivores. Therefore, we aimed to elucidate if Stryphnodendron adstringens (Fabaceae), a common Cerrado tree species, when subjected to damage (by manual leaf cutting and experimental fire) would produce a greater number of EFNs and changes its nectar quality on newly produced leaves in comparison with plants not subjected to these treatments. Leaf damage was performed artificially directly on the plant branches and at the entire plant canopy (by means of scissors or fire events). Extrafloral nectary density was higher in new leaves produced after the treatment application (artificial herbivory and fire) in comparison with plants under control treatment. The amount of nectar was also higher under treatments in comparison with control, with a significant change on nectar quality in plants subjected to the treatments of artificial herbivory. The results provided support for the hypothesis that EFNs are an inducible defensive strategy in S. adstringens, confirming the existence of phenotypic plasticity given environmental pressures.
    Keywords Stryphnodendron adstringens ; canopy ; cerrado ; herbivores ; leaves ; nectar ; nectar secretion ; nectaries ; phenotypic plasticity ; trees
    Language English
    Dates of publication 2022-07
    Size p. 268-277.
    Publishing place John Wiley & Sons Australia, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 2020484-X
    ISSN 1442-1984 ; 0913-557X
    ISSN (online) 1442-1984
    ISSN 0913-557X
    DOI 10.1111/1442-1984.12373
    Database NAL-Catalogue (AGRICOLA)

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  6. Article: Woody plant encroachment constrains regeneration of ground‐layer species in a neotropical savanna from seeds

    Pinheiro, Luiz Felipe Souza / Kansbock, Leticia / Rossatto, Davi Rodrigo / Kolb, Rosana Marta

    Austral ecology. 2022 May, v. 47, no. 3

    2022  

    Abstract: Woody plants have been encroaching into savannas on a global scale. Global climatic changes, along with changes to disturbance regimes, are considered to be the main drivers of this process. Particularly, many formerly open physiognomies of the Brazilian ...

    Abstract Woody plants have been encroaching into savannas on a global scale. Global climatic changes, along with changes to disturbance regimes, are considered to be the main drivers of this process. Particularly, many formerly open physiognomies of the Brazilian savanna have become encroached by woody species over the course of a few decades under fire suppression. In this scenario, many typical savanna species of the ground‐layer are reducing their above‐ground presence, possibly due to change in environmental filtering as a result of encroachment. Consequently, at encroachment sites, changes to microhabitats occur, such as less incident light to the soil surface, reduced red:far‐red ratios and soil surface temperatures, and increased litter deposition. These changes may hinder the regenerative capacity of ground‐layer savanna species. This study investigated the role of encroachment‐induced environmental changes as filters for the recruitment ability of ground‐layer savanna species. We examined the germination and seedling emergence of 12 species under controlled conditions, simulating natural aspects of encroached and non‐encroached sites of the Brazilian savanna. The germination and/or seedling emergence of all species examined were/was negatively affected by the simulated environmental filtering changes. Increased litter deposition reduced seedling emergence more than temperature and light affected germination. Filtering changes caused by woody encroachment represent a bottleneck for the regeneration from seeds of ground‐layer savanna species. Filtering changes by woody encroachment is one of the underlying mechanism explaining changes in species presence in savannas, and it ultimately leads to positive feedback loops wherein woody encroachment begets more woody encroachment.
    Keywords Neotropics ; fire suppression ; germination ; savannas ; seedling emergence ; soil ; woody plants
    Language English
    Dates of publication 2022-05
    Size p. 674-684.
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 2019899-1
    ISSN 1442-9993 ; 1442-9985
    ISSN (online) 1442-9993
    ISSN 1442-9985
    DOI 10.1111/aec.13156
    Database NAL-Catalogue (AGRICOLA)

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

    Pinheiro, Luiz Felipe Souza / Pilon, Natashi Aparecida Lima / Rossatto, Davi Rodrigo / Kolb, Rosana Marta

    Journal of vegetation science. 2022 Mar., v. 33, no. 2

    2022  

    Abstract: AIM: Woody‐plant encroachment is a reality in many savannas worldwide, leading savannas to become replaced by forest ecosystems. As tree density and cover increase, increased shade and litter deposition may suppress the savanna's community of low‐lying ... ...

    Abstract AIM: Woody‐plant encroachment is a reality in many savannas worldwide, leading savannas to become replaced by forest ecosystems. As tree density and cover increase, increased shade and litter deposition may suppress the savanna's community of low‐lying plants. By using field manipulation, we tested shading and litter effects, alone and in combination, on the savanna's ground‐layer plant community. We investigated how changes in these environmental factors may affect the composition, structure, and above‐ground biomass in the plant community of a species‐rich Neotropical savanna. LOCATION: Savanna patches in the Cerrado, southeastern Brazil. METHODS: Annual surveys of the herbaceous–shrub layer in a three‐year field manipulation experiment examining shading and litter deposition. RESULTS: Shade negatively affected all evaluated parameters, while litter addition had only minor effects. The largest losses of richness, density, and cover occurred in forbs and grasses. Increased shade resulted in a sharp decrease in the above‐ground biomass of monocots. CONCLUSIONS: Our results show that light is a strong environmental filter for the ground‐layer community. The reductions in grass cover and biomass under shade treatments likely altered ecosystem functioning. Woody encroachment can thus be considered to represent a process that can alter the structure and functioning of savannas. Management interventions should therefore be taken to prevent woody encroachment or mitigate its harmful effects on savanna biodiversity and ecosystem functioning.
    Keywords Liliopsida ; Neotropics ; aboveground biomass ; biodiversity ; cerrado ; forbs ; forests ; grasses ; plant communities ; savannas ; Brazil
    Language English
    Dates of publication 2022-03
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 1053769-7
    ISSN 1100-9233
    ISSN 1100-9233
    DOI 10.1111/jvs.13118
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Congeneric savanna-forest species have similar reproductive phenologies

    de Oliveira, João Pedro Machado / Massi, Klécia Gili / Rossatto, Davi Rodrigo

    SAAB South African journal of botany. 2022 Jan., v. 144

    2022  

    Abstract: The time for flowering and fruiting in plants is mainly influenced by environmental factors. Plant species that are subject to different environmental conditions, but phylogenetically close, such as forest and savanna congeneric species pairs growing in ... ...

    Abstract The time for flowering and fruiting in plants is mainly influenced by environmental factors. Plant species that are subject to different environmental conditions, but phylogenetically close, such as forest and savanna congeneric species pairs growing in forest-savanna transitions in the Neotropics, can be comparatively studied to isolate the effects of the environment from phylogenetic influences. Thus, we performed a comparative study of flowering and fruiting start and duration, as well its relationships with dispersal modes and canopy phenology, analyzing herbarium data for 25 congeneric species pairs from different families, each containing at least one savanna and one forest species. We examined species phenological patterns using digitized specimens from one of the most comprehensive digitized plant datasets in Brazil, the SpeciesLink. We found savanna species having shorter flowering duration (2–5 months) in comparison with forest (3–8 months) congeneric species. Congeneric pairs presented similar reproductive phenological responses for all other studied traits. We found that dispersal mode played an important role in determining fruiting start and duration, while flowering and fruiting start were explained by leaf deciduousness. Although there were many phenological similarities between savanna and forest species, there were differences in flowering duration between savanna and forest species in some congeneric pairs.
    Keywords Neotropics ; canopy ; comparative study ; data collection ; forests ; herbaria ; leaves ; phenology ; phylogeny ; savannas ; Brazil
    Language English
    Dates of publication 2022-01
    Size p. 347-354.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 2126918-X
    ISSN 0254-6299
    ISSN 0254-6299
    DOI 10.1016/j.sajb.2021.09.018
    Database NAL-Catalogue (AGRICOLA)

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  9. Article ; Online: Expanding our understanding of leaf functional syndromes in savanna systems: the role of plant growth form.

    Rossatto, Davi Rodrigo / Franco, Augusto Cesar

    Oecologia

    2017  Volume 183, Issue 4, Page(s) 953–962

    Abstract: The assessment of leaf strategies has been a common theme in ecology, especially where multiple sources of environmental constraints (fire, seasonal drought, nutrient-poor soils) impose a strong selection pressure towards leaf functional diversity, ... ...

    Abstract The assessment of leaf strategies has been a common theme in ecology, especially where multiple sources of environmental constraints (fire, seasonal drought, nutrient-poor soils) impose a strong selection pressure towards leaf functional diversity, leading to inevitable tradeoffs among leaf traits, and ultimately to niche segregation among coexisting species. As diversification on leaf functional strategies is dependent on integration at whole plant level, we hypothesized that regardless of phylogenetic relatedness, leaf trait functional syndromes in a multivariate space would be associated with the type of growth form. We measured traits related to leaf gas exchange, structure and nutrient status in 57 coexisting species encompassing all Angiosperms major clades, in a wide array of plant morphologies (trees, shrubs, sub-shrubs, herbs, grasses and palms) in a savanna of Central Brazil. Growth forms differed in mean values for the studied functional leaf traits. We extracted 4 groups of functional typologies: grasses (elevated leaf dark respiration, light-saturated photosynthesis on a leaf mass and area basis, lower values of leaf Ca and Mg), herbs (high values of SLA, leaf N and leaf Fe), palms (high values of stomatal conductance, leaf transpiration and leaf K) and woody eudicots (sub-shrubs, shrubs and trees; low SLA and high leaf Ca and Mg). Despite the large range of variation among species for each individual trait and the independent evolutionary trajectory of individual species, growth forms were strongly associated with particular leaf trait combinations, suggesting clear evolutionary constraints on leaf function for morphologically similar species in savanna ecosystems.
    MeSH term(s) Grassland ; Phylogeny ; Plant Development ; Plant Leaves/anatomy & histology ; Syndrome ; Trees
    Language English
    Publishing date 2017-04
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 123369-5
    ISSN 1432-1939 ; 0029-8549
    ISSN (online) 1432-1939
    ISSN 0029-8549
    DOI 10.1007/s00442-017-3815-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: How does mistletoe infection affect seasonal physiological responses of hosts with different leaf phenology?

    Scalon, Marina Corrêa / Rossatto, Davi Rodrigo / Franco, Augusto Cesar

    Flora. 2021 Aug., v. 281

    2021  

    Abstract: Plants should have the ability to perceive physiological changes within their branches when infected by mistletoes, adjusting the use of resources between infected and uninfected branches which can be crucial for their survival in the long-term. Here we ... ...

    Abstract Plants should have the ability to perceive physiological changes within their branches when infected by mistletoes, adjusting the use of resources between infected and uninfected branches which can be crucial for their survival in the long-term. Here we investigated how branches infected by the mistletoe Passovia ovata (Pohl ex DC.) Tiegh. and uninfected branches within the same individual tree respond to seasonal environmental changes across two hosts of contrasting leaf phenology (the evergreen Miconia albicans (SW.) Triana and the deciduous Byrsonima verbascifolia (L.) DC.). We measured key leaf traits (instantaneous gas exchange rates, diurnal courses of stomatal conductance, leaf water potential, specific leaf area and leaf macronutrient concentrations) during the peak of the wet and dry season in a seasonal savanna of central Brazil. Pre-dawn leaf water potentials were consistently more negative for infected branches of both hosts, suggesting that overnight water refilling of infected branches was more limited. However, infected and uninfected branches exhibited similar leaf water potentials at midday, suggesting that they undergo similar imbalances in water supply and demand during periods of high atmospheric evaporative demand. Infected and non-infected branches of the evergreen mistletoe showed tighter regulation of water loss, whereas infected branches of the deciduous host were less constrained in regulating leaf transpiration. We also found differences for nutrient concentrations: N, P and K were lower, while Ca was higher in leaves of infected branches. Physiological changes induced by mistletoe infection affected host performance, and were reflected in water and nutrient use differences between infected and uninfected branches. Our findings show that infection responses by mistletoes can be detected between branches within individual trees, and that host species with distinct patterns of leaf phenology are capable to adjust, at the individual level, to cope with mistletoe's imposed physiological stress throughout the year.
    Keywords Byrsonima verbascifolia ; Miconia albicans ; Santalales ; dry season ; evaporative demand ; flora ; gas exchange ; hosts ; leaf water potential ; leaves ; phenology ; savannas ; specific leaf area ; stomatal conductance ; supply balance ; trees ; water supply ; Brazil
    Language English
    Dates of publication 2021-08
    Publishing place Elsevier GmbH
    Document type Article
    ZDB-ID 5580-3
    ISSN 0367-2530 ; 0373-6490
    ISSN 0367-2530 ; 0373-6490
    DOI 10.1016/j.flora.2021.151871
    Database NAL-Catalogue (AGRICOLA)

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