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1.
Ecol Lett ; 27(5): e14415, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38712683

RESUMEN

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.


Asunto(s)
Hojas de la Planta , Ciclo del Carbono , Carbono/metabolismo
5.
An Acad Bras Cienc ; 93(2): e20200119, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34133536

RESUMEN

The native flora of the Brazilian rupestrian grassland (campos rupestres) is threatened by the spread of invasive grasses. In this study, we evaluated the effect of habitat on the functional traits and CSR ecological strategies of three invasive alien grasses occurring both in the ironstone (IRG) and quartzitic (QRG) rupestrian grassland habitats. Although in both habitats the invasive species predominantly showed a stress-tolerant strategy, they exhibited distinct degrees of stress-tolerance and slightly differences in functional traits values in the IRG compared to the QRG. Habitat type distinctly influenced invasive grasses functional traits and ecological strategies, revealing a species-specific pattern.


Asunto(s)
Pradera , Poaceae , Brasil , Ecosistema , Especies Introducidas
6.
An Acad Bras Cienc ; 92(suppl 2): e20190058, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33146275

RESUMEN

Elevation creates a variety of physical conditions in a relatively short distance, which makes mountains suitable for studying the effects of climate change on biodiversity. We investigated the importance of climate and vegetation for the distribution of butterflies from 800 to 1400 m elevation. We sampled butterflies, and woody and rosette plants and measured air temperature and humidity, wind speed and gust, and solar radiation. We partitioned diversity to assess the processes underlying community shifts across altitudes - species loss versus replacement. We assessed the strength of the association among butterfly, vegetation, and climate. Butterfly richness and abundance decreased with altitude, and species composition changed along the elevation. Changes in butterfly composition with altitude were mainly through species replacement and by abundance increases in some species being compensated by decreases in others. Since the floristic diversity decreased with altitude due to soil conditions, and butterflies are closely related to their host plants, this could explain species replacement with altitude. Overall, we found a stronger association of butterfly community with vegetation than climate, but plant community and climate were also strongly associated between them. Butterfly richness was more strongly associated with plant richness than with temperature, while the reverse was true for butterfly abundance, which was more strongly associated with temperature than with plant richness. We must consider the complementary roles of resource and conditions in species distribution.


Asunto(s)
Mariposas Diurnas , Altitud , Animales , Biodiversidad , Cambio Climático , Ecosistema , Suelo
7.
An Acad Bras Cienc ; 91(1): e20180162, 2019 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-30916155

RESUMEN

We compiled published Brazilian gall-inducing insect inventories aiming to understand trends and biases in this field research and to investigate the factors that potentially explain the diversity of gall-inducing insects among different sampling sites. A total of 51 studies with gall-inducing insect inventories were compiled for Brazil, which sampled 151 sites in 88 municipalities, 13 states and five regions. The number of papers published on gall-inducing insects per year has increased over the last 30 years, being Cecidomyiidae (Diptera) the main galling taxon, Fabaceae the main host-plant family and Protium heptaphyllum (Burseraceae) the most important super-host species in these inventories. We found a great bias in the geographical distribution of Brazilian inventories, with the majority of studies in the Southeast region, and Atlantic Forest and Cerrado biomes. The total richness of gall-inducing insects differed significantly among regions and biomes, with higher gall richnesses being recorded in the North region and Amazon biome. However, Brazilian regions and biomes did not vary in richness of gall-inducing insect morphotypes per plant species. According our results, sampling by cecidologists in less studied regions of Brazil is needed, particularly in the North and South regions and subsampled biomes such as the Amazon, Pampas and Pantanal.


Asunto(s)
Ecosistema , Bosques , Insectos/fisiología , Plantas/parasitología , Distribución Animal , Animales , Biodiversidad , Brasil , Dilleniaceae/crecimiento & desarrollo , Interacciones Huésped-Parásitos
8.
An Acad Bras Cienc ; 90(4): 3353-3361, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30184009

RESUMEN

The theory of landscape ecology applied to the methods of spatial analysis helps to understand changes in the structure of forest remnants. In view of this theory, the objective of the present study was to analyze the structure of a fragmented area between the years 1979 and 2015 through calculation of landscape metrics for arboreal, shrubby and herbaceous vegetation classes. Vegetation classes were classified with visits to the field, interpretation of aerial photographs from 1979 and supervised classification of Landsat 8 from 2015. The metrics calculated for each class were area and total number of fragments, total edge and average connectivity among the fragments. The analysis of structure found that it changed negatively due to an increase in the number of small fragments, which increased the intensity of edge effects and reduced connectivity between fragments for all classes.


Asunto(s)
Monitoreo del Ambiente/métodos , Bosques , Fotograbar , Comunicaciones por Satélite , Brasil , Análisis Espacial
9.
Environ Monit Assess ; 164(1-4): 369-77, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19353281

RESUMEN

For decades, several native medicinal species have been used by the pharmaceutical industry in Brazil to create commercial products. In 1995, the Ministry of Health, following the recommendations of the World Health Organization, established herbal regulations (RDC 17) in order to improve the quality of such products. In fact, only plant species with conclusive results from pharmacological and toxicological studies can be used for creating medicines. In this study, we evaluated the consequences of RDC 17 on the use and conservation of native medicinal plants by comparing the plant material used by six companies in 1995/1996 and 10 years later (2005/2006). Eighty-three different species were used in 1995/1996, 50 of them native (60.2%), 16 exotic (19.3%), and 17 imported (20.5%). In 2005/2006, 44 species were used by the companies and only 19 (43.2%) were native. The category of plant material that saw the largest decrease in use was roots, and in 2005/2006 leaves were more used. The study shows a strong reduction in the collection of native species signalizing the importance of herbal regulations on their conservation. It also points to the need for pharmacological and toxicological studies of the Brazilian native medicinal flora, as well as studies on their ecology and conservation.


Asunto(s)
Conservación de los Recursos Naturales , Plantas Medicinales , Brasil , Plantas Medicinales/clasificación , Especificidad de la Especie
10.
Neotrop Entomol ; 35(4): 435-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17061789

RESUMEN

The frequency of galls induced by Anisodiplosis waltheriae Maia, a recently described species, on Waltheria indica L. was studied. W indica is an invasive weed in regeneration areas of Atlantic Forest in southeastern Brazil. Plants were collected in May 2004 and above-ground biomass, main stem length, number of leaves, number of galls per leaf and leaf area of each individual were recorded. Nearly 90% of all plants and 25% of all leaves were attacked by the gall midge, with an average of 0.67 galls/leaf. Leaf area had a weak effect on gall abundance while the number of leaves had no effect on gall abundance. Only 31% of the variation in gall abundance was explained by plant biomass. Natural enemies killed one third of the sampled galls. Predation accounted for 22.9% of gall mortality, unknown factors killed 7.6%, microhymenopteran parasitoids killed 2.5% and fungi only 1%. Mortality factors were not influenced by leaf area or gall density.


Asunto(s)
Dípteros , Malvaceae , Tumores de Planta/parasitología , Animales
11.
Neotrop. entomol ; 35(4): 435-439, July-Aug. 2006. ilus, graf
Artículo en Inglés | LILACS | ID: lil-451240

RESUMEN

The frequency of galls induced by Anisodiplosis waltheriae Maia, a recently described species, on Waltheria indica L. was studied. W. indica is an invasive weed in regeneration areas of Atlantic Forest in southeastern Brazil. Plants were collected in May 2004 and above-ground biomass, main stem length, number of leaves, number of galls per leaf and leaf area of each individual were recorded. Nearly 90 percent of all plants and 25 percent of all leaves were attacked by the gall midge, with an average of 0.67 galls/leaf. Leaf area had a weak effect on gall abundance while the number of leaves had no effect on gall abundance. Only 31 percent of the variation in gall abundance was explained by plant biomass. Natural enemies killed one third of the sampled galls. Predation accounted for 22.9 percent of gall mortality, unknown factors killed 7.6 percent, microhymenopteran parasitoids killed 2.5 percent and fungi only 1 percent. Mortality factors were not influenced by leaf area or gall density.


Estudou-se a freqüência de galhas induzidas por Anisodiplosis waltheriae Maia, espécie recentemente descrita, em Waltheria indica L. W. indica é uma erva invasora em áreas de regeneração de Floresta Atlântica no Sudeste do Brasil. As plantas foram coletadas em maio de 2004 e a biomassa aérea, comprimento do caule, número de folhas, número de galhas por folha e área foliar de cada indivíduo foram registrados. Quase 90 por cento das plantas e 25 por cento das folhas foram atacadas, com a média de 0,67 galhas/folha. A área foliar pouco influenciou o número de galhas, porém o número de folhas não afetou a abundância de galhas (P > 0,05). Apenas 31 por cento da variação no número de galhas foi explicada pela biomassa da planta. Um terço das galhas foi morta por inimigos naturais. A predação explicou 22,9 por cento da mortalidade, fatores desconhecidos mataram 7,6 por cento, microhimenópteros parasitóides mataram 2,5 por cento e fungos apenas 1 por cento. Os fatores de mortalidade não foram influenciados pela área foliar nem densidade de galhas.


Asunto(s)
Animales , Dípteros , Tumores de Planta/parasitología , Malvaceae
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