Papers by ALESSANDRA RODRIGUES KOZOVITS
Research Square (Research Square), Jun 27, 2023
In recent decades, the role played by planted forests in carbon sequestration and storage has bee... more In recent decades, the role played by planted forests in carbon sequestration and storage has been recognized as an essential ecosystem service for maintaining the quality of life on the planet. In this study we compared the carbon stocks in soil, litter and aboveground tree biomass in four riparian reforested strips in the surroundings of the State Hydroelectric Power Plant (UHE) of Volta Grande in Minas Gerais, Brazil. The planted forest strips ranged from 30 to 100 m wide and 10 to 20 years old. Despite this, no signi cant differences (p < 0.5) were found in C stocks among areas. Carbon stock in trees was about 86tMgC.ha − 1 on average. Litter carbon stocks varied from 4.15 to 6.59 MgC.ha − 1 and in the soil (0-30 cm), the values were about 31 MgC.ha − 1. Litter carbon stock was only signi cantly higher in narrower strips at (p < 0.1) probably due to an edge effect. Our results suggest that factors such as the management and protection of the reforested area and the surrounding landscape seem to exert a strong in uence on the quality of the reforested fragments. Regardless, the reforested areas in the new riparian zones created on the banks of the dam increased C stocks by 40% in the rst decade compared to the baseline of agricultural environments. This result corroborates other studies and encourages the restoration of riparian zones as an e cient and rapid mechanism for C sequestration plus other ecosystem services.
Plant Cell and Environment, Aug 1, 2007
Combined d 13 C and d 18 O analyses of leaf material were used to infer changes in photosynthetic... more Combined d 13 C and d 18 O analyses of leaf material were used to infer changes in photosynthetic capacity (Amax) and stomatal conductance (gl) in Fagus sylvatica and Picea abies trees growing under natural and controlled conditions. Correlation between gl and d 18 O in leaf cellulose (d 18 Ocel) allowed us to apply a semi-quantitative model to infer gl from d 18 Ocel and also interpret variation in d 13 C as reflecting variation in Amax. Extraction of leaf cellulose was necessary, because d 18 O from leaf organic matter (d 18 OLOM) and d 18 Ocel was not reliably correlated. In juvenile trees, the model predicted elevated carbon dioxide (CO2) to reduce Amax in both species, whereas ozone (O3) only affected beech by reducing CO2 uptake via lowered gl. In adult trees, Amax declined with decreasing light level as gl was unchanged. O3 did not significantly affect isotopic signatures in leaves of adult trees, reflecting the higher O3 susceptibility of juvenile trees under controlled conditions. The isotopic analysis compared favourably to the performance of leaf gas exchange, underlining that the semi-quantitative model approach provides a robust way to gather time-integrated information on photosynthetic performance of trees under multi-faced ecological scenarios, in particular when information needed for quantitative modelling is only scarcely available.
Microbial Ecology, Jan 28, 2023
Restoration Ecology, Jun 21, 2023
Journal of Apicultural Research, Jun 13, 2022
Phytochemistry, Oct 1, 2021
The cuticle is the outermost region of the epidermal cell wall of plant aerial organs. The cuticl... more The cuticle is the outermost region of the epidermal cell wall of plant aerial organs. The cuticle acts as a two-way lipid barrier for water diffusion; therefore, it plays a vital role in foliar water uptake (FWU). We hypothesised that the chemical composition of the cuticular waxes influences the FWU strategy that plants adopt in a foggy tropical ecosystem. We analysed the leaf cuticular waxes of six plant species known by their different FWU strategies, in both qualitative and quantitative approaches, to test this hypothesis. We also investigated the fine structure of the plant cuticle by scanning electron microscopy. Neither the total wax loads nor the amounts of single wax compound classes correlated to the FWU. In contrast, the qualitative chemical composition of the cuticular waxes was related to the water absorption speed but not to the maximum water absorbed. The presence of wax crystals might interfere with the FWU. Our findings suggest that a complex three-dimensional network of the cuticular compounds contributes to different strategies of FWU in six plant species from foggy tropical mountaintops.
Ecology
Advancing functional ecology depends fundamentally on the availability of data on reproductive tr... more Advancing functional ecology depends fundamentally on the availability of data on reproductive traits, including those from tropical plants, which have been historically underrepresented in global trait databases. Although some valuable databases have been created recently, they are mainly restricted to temperate areas and vegetative traits such as leaf and wood traits. Here, we present Rock n' Seeds, a database of seed functional traits and germination experiments from Brazilian rock outcrop vegetation, recognized as outstanding centers of diversity and endemism. Data were compiled through a systematic literature search, resulting in 103 publications from which seed functional traits were extracted. The database includes information on 16 functional traits for 383 taxa from 148 genera, 50 families, and 25 orders. These 16 traits include two dispersal, six production, four morphological, two biophysical, and two germination traits—the major axes of the seed ecological spectrum. ...
Ciencia Florestal, 2014
Taxas de germinação de sementes, sobrevivência e crescimento de plantas, parâmetros estes avaliad... more Taxas de germinação de sementes, sobrevivência e crescimento de plantas, parâmetros estes avaliados no presente estudo, são informações essenciais para a caracterização do potencial biológico de espécies para uso em processos de recuperação de áreas degradadas. A falta de conhecimento sobre tais aspectos em espécies nativas têm justificado o uso de plantas exóticas na revegetação de voçorocas em todo o Brasil. Entretanto, especialmente em locais sujeitos à grande sazonalidade climática e sobre solos oligotróficos, espécies exóticas nem sempre apresentam bom desempenho, levando o empreendimento de revegetação ao insucesso ou elevando consideravelmente a necessidade de aplicação de tratos culturais. Com o objetivo de ampliar os conhecimentos sobre o potencial biológico para revegetação em voçorocas de plantas nativas do cerrado e de uma gramínea exótica, que vem sendo amplamente usada em projetos de contenção de erosão, plântulas e touceiras das espécies nativas Cratylia argentea (Desv.) Kuntze e Echinolaena inflexa (Poir.) Chase, e da exótica Vetiveria zizanioides (L.) Nash foram transferidas para o colúvio de uma voçoroca no município de Ouro Preto-MG, onde permaneceram durante a estação seca de 2010 sem aplicação de fertilizantes ou irrigação. Em blocos ao acaso, parcelas de 1 x 1 m receberam aleatoriamente quatro tratamentos de plantio: touceiras de Echinolaena inflexa ou de Vetiveria zizanioides; e touceiras destas gramíneas em consórcio com a leguminosa arbustiva Cratylia argentea. Todas as gramíneas e 73% das plântulas da leguminosa sobreviveram. Como esperado, a cobertura verde de Echinolaena Inflexa diminuiu ao longo da estação seca, tendo, entretanto, rebrotado após as primeiras chuvas. Vetiveria zizanioides manteve a área foliar ativa e apresentou crescimento significativo no período. Cratylia argentea apresentou altas taxas de germinação de sementes e de crescimento, entretanto, nodulação ocorreu em apenas dois indivíduos. Assim, não houve influência da leguminosa no crescimento das gramíneas. Os resultados indicam que tanto as espécies nativas do cerrado como a gramínea exótica possuem alto potencial para revegetação em colúvio de voçoroca, tendo sobrevivido ao período crítico de seca e sobre substrato oligotrófico sem adição de fertilizantes ou irrigação. Palavras-chave: Cratylia argentea; Echinolaena inflexa; revegetação; voçoroca.
Restoration of tropical riparian forests is challenging, since these ecosystems are the most dive... more Restoration of tropical riparian forests is challenging, since these ecosystems are the most diverse, dynamic, and complex physical and biological terrestrial habitats. This study tested whether biodiversity can predict ecosystem functions in a human-impacted tropical riparian forest.We explored the effects of several biodiversity components (taxonomic or functional groups) on different ecosystem functions associated with restored riparian forestsOverall, 49% of the biodiversity components showed positive effects on ecosystem functions, each component to a different degree. In general, our results showed that both taxonomic and functional biodiversity had strong effects on ecosystem functions indicating that floral and faunal biodiversity enhanced the multifunctionality of these restored riparian tropical forests.These findings indicate that in restored riparian forests, recovery of biodiversity is followed by improvement in important ecosystem functions that are the basis for succe...
American Journal of Botany, 2019
PremiseFog is a frequent event in Brazilian rupestrian field and plays an important role in the p... more PremiseFog is a frequent event in Brazilian rupestrian field and plays an important role in the physiology of several plant species. Foliar water uptake (FWU) of fog may be fast or slow depending on the species. However, fog water may negatively affect CO2 assimilation. Thus, the interference in the water and carbon balance as a result of different strategies of FWU was evaluated to verify whether fog may mitigate possible water deficit in leaves.MethodsFour plant species with different FWU strategies were studied in a ferruginous rupestrian field with frequent fog. Gas exchange and water potential were measured before dawn and at midday during the dry and rainy seasons, separating foggy from non‐foggy days during the dry season.ResultsThe FWU speed negatively influences CO2 assimilation in the dry season, possibly because of its negative relationship with stomatal conductance, since reduced stomatal aperture impairs carbon entrance. Fog presence increased leaf water potential both ...
Journal of Forestry Research, 2017
The control of exotic and invasive species in areas undergoing recovery is a challenge for ecolog... more The control of exotic and invasive species in areas undergoing recovery is a challenge for ecological restoration and this problem may be even greater in urbanized areas. This study evaluated the seed bank and seed rain of a 5-year-old riparian forest located at the metropolitan region of Belo Horizonte in southeast Brazil, and verified changes over time in the abundance and species richness and whether planted species already were providing propagules to the site. At the forest, fifteen parcels of 100 m 2 were distributed randomly and soil samples were collected thrice (October 2011, March 2012 and July 2012) to evaluate the seed bank. Seed traps were installed in nine parcels to collect propagules over 1 year. Propagules were segregated and germinate at greenhouse. Species richness and abundance were estimated, and variance and similarity were quantified. In total, 86 species were recorded in the seed banks, 41.9% natives and 33.7% exotics, with the predominance of herbs (87.2%) and only 7% of trees. Species classified as weeds amounted to 52.3%. In the seed rain 642 seedlings germinated but they belonged to only 10 species, half of them were exotics. Regarding life forms, half of the species were arboreal and dominated the samples, highlighting the exotic species Melia azedarach. The species richness of the seed bank did not differ by season, unlike the seed rain which varied significantly by month. Seed bank and seed rain species had a very low floristic similarity with the list of planted species, suggesting that few planted trees had dispersed or were stocking propagules. Many non-planted species were recorded, mostly exotics and/or invasive that were probably derived from the surrounding urban matrix. These might interrupt the successional dynamics of the restoration forest and compromise the restoration process in the medium and long-terms. Our results highlight: (1) the importance of monitoring areas undergoing restoration; (2) that restoration methods and management actions directed to control exotic and invasive species are particularly important for sites in urban regions; and (3) the relevance of conserving forest fragments as sources of propagules for nearby areas.
Tree Physiology, 2017
Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climat... more Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climate system, yet are threatened by climate change (CC) and associated air pollution (AP, highlighting ozone (O 3) and nitrogen oxides (NOx)). We adopt the perspective that CC-AP drivers and physiological impacts are universal, resulting in consistent stress responses of forest ecosystems across zonobiomes. Evidence supporting this viewpoint is presented from the literature on ecosystem gross/net primary productivity and water cycling. Responses to CC-AP are compared across evergreen/deciduous foliage types, discussing implications of nutrition and resource turnover at tree and ecosystem scales. The availability of data is extremely uneven across zonobiomes, yet unifying patterns of ecosystem response are discernable. Ecosystem warming results in trade-offs between respiration and biomass production, affecting high elevation forests more than in the lowland tropics and low-elevation temperate zone. Resilience to drought is modulated by tree size and species richness. Elevated O 3 tends to counteract stimulation by elevated carbon dioxide (CO 2). Biotic stress and genomic structure ultimately determine ecosystem responsiveness. Aggrading early-rather than mature late-successional communities respond to CO 2 enhancement, whereas O 3 affects North American and Eurasian tree species consistently under free-air fumigation. Insect herbivory is exacerbated by CC-AP in biome-specific ways. Rhizosphere responses reflect similar stand-level nutritional dynamics across zonobiomes, but are modulated by differences in tree-soil nutrient cycling between deciduous and evergreen systems, and natural versus anthropogenic nitrogen (N) oversupply. The hypothesis of consistency of forest responses to interacting CC-AP is supported by currently available data, establishing the precedent for a global network of long-term coordinated research sites across zonobiomes to simultaneously advance both bottom-up (e.g., mechanistic) and top-down (systems-level) understanding. This global, synthetic approach is needed because high biological plasticity and physiographic variation across individual ecosystems currently limit development of predictive models of forest responses to CC-AP. Integrated research on C and nutrient cycling, O 3-vegetation interactions and water relations must target mechanisms' ecosystem responsiveness. Worldwide case studies must be subject to biostatistical exploration to elucidate overarching response patterns and synthesize the resulting empirical data through advanced modelling, in order to provide regionally coherent, yet globally integrated information in support of internationally coordinated decision-making and policy development.
Functional Ecology, 2007
Summary Deposition of nutrients due to anthropogenic activities has the potential to change nutri... more Summary Deposition of nutrients due to anthropogenic activities has the potential to change nutrient availability in nutrient‐limited ecosystems with consequences for plant and ecosystem processes. Species‐specific and ecosystem responses to the addition of nutrients were studied in a field experiment conducted in a Savanna (Cerrado sensu stricto) on dystrophic soil in central Brazil. Three fertilization treatments (N, P and N plus P additions) and unfertilized control were replicated in four 15 × 15 m plots per treatment. Five of the dominant woody species were studied. Specific leaf area (SLA) was not affected by the treatments, but species responded differently in terms of foliar nutrient concentration, resorption efficiency and proficiency to the increased soil N and P availability. Responses of N and P resorption suggested different levels of regulation for these two limiting elements, with a decrease in N and P resorption proficiency depending on the treatment. In general, und...
Restoration Ecology
To achieve the ambitious goals of the UN Decade on Ecosystem Restoration, restoration frameworks ... more To achieve the ambitious goals of the UN Decade on Ecosystem Restoration, restoration frameworks should embrace the diversity of ecosystems found on Earth, including open‐canopy ecosystems, which have been largely overlooked. Considering the paucity of scientific foundations promoting restoration science, policy, and practice for open tropical ecosystems, we provide overarching guidelines to restore the campo rupestre, a Neotropical, open megadiverse grassland that has been increasingly threatened by multiple human activities, especially mining. Restoration techniques for tropical grasslands are still at its infancy, and attempts to restore campo rupestre have had, so far, low to moderate success, highlighting the need for a tailored restoration framework. In a scenario of increasing degradation and scarcity of on‐site restoration experiments, we propose 10 principles to improve our ability to plan, implement, and monitor restoration in campo rupestre: (1) include socioeconomic dime...
Ecología austral, Aug 13, 2021
A�������. Among the limitations for the use of direct seeding in the ecological restoration of se... more A�������. Among the limitations for the use of direct seeding in the ecological restoration of severely degraded areas in tropical grasslands, the association between dry periods and an inhospitable substrate stands out. This work evaluated whether covering seed with a soil layer and the addition of a thin topsoil layer to the degraded substrate interferes with native plant establishment in degraded areas. The effect of rainfall variations on direct seeding results was also measured. The establishment of seven native species was evaluated under four different conditions: 1) seeding on degraded substrate, 2) seeding covered by 1 cm degraded substrate layer, 3) seeding on 1cm topsoil layer, and 4) seeding covered by 1 cm topsoil layer. In general, species with smaller seeds showed higher establishment percentages in treatments in which seeds were deposited on the substrate. Legume species, which have larger seeds, achieved be�er establishment percentage when seeds were covered by the substrate. The addition of topsoil was beneficial for Bulbostylis fimbriata (Cyperaceae), while for the other species, the effect was null or harmful. Data also showed that rainfall amount and distribution affected the establishment rate. Direct seeding is an advantageous alternative for the ecological restoration of tropical grassland degraded by mining. Be�er knowledge on sowing management and behavior of native species can contribute to improving the efficiency of this technique.
SSRN Electronic Journal, 2022
Studies on storage and thermal shocks allow a better understanding of the physiology of the speci... more Studies on storage and thermal shocks allow a better understanding of the physiology of the species and possible inferences about natural regeneration, management or recovery of degraded areas. This study analyzed the influence of high temperatures and storage on germination of native species from Brazilian Grasslands (Eupatorium tanacetifolium, Vernonia flexuosa, Schlechtendalia luzulifolia and Desmanthus tatuhyensis). Seeds stored for 36 months were subjected to 5 treatments (thermal shock of 60°C, 80°C and 100°C, light and dark controls) and kept for 60 days in a germination chamber (12/12 h, 20/30°C) and tetrazolium test was performed with non-germinated seeds. Seeds of all species showed low germination, with no significant difference between controls and heat shock treatments. Storage reduced the percentage of germination of E. tanacetifolium and S. luzulifolia, this one is in the list of extinction threatened species. The other species were not affected by storage, indicating...
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Papers by ALESSANDRA RODRIGUES KOZOVITS