19 research outputs found
Phenotypic plasticity and the leaf economics spectrum: plasticity is positively associated with specific leaf area
Phenotypic plasticity is a key mechanism by which plants respond to changing or heterogeneous conditions. Efforts to predict phenotypic plasticity across plant species have mainly focused on environmental variability or abiotic conditions, i.e. site characteristics. However, the considerable variation in phenotypic plasticity within sites calls for alternative approaches. Different functional groups are thought to differ in their plasticity levels. Further, traits such as leaf specific area (SLA), leaf area (LA) and maximum photosynthetic rate (Amax) reflect central aspects of plant strategies. Lower values of SLA, LA and Amax are indicative of a resource-conservative strategy, which is thought to be associated with lower phenotypic plasticity. We used meta-analytical data to test whether plant functional group (herbs, woody deciduous and woody evergreens) and SLA, LA and Amax are associated with phenotypic plasticity in four trait types: biomass allocation, plant size, leaf morphology and physiology. We obtained data from 168 plant species and accounted for phylogenetic relationships in all analyses. We found a positive relationship between SLA and phenotypic plasticity in biomass allocation, leaf morphology and physiology, with differences across functional groups. In contrast, there was no evidence of greater plasticity in plant size in species with higher SLA; rather the opposite was true for woody evergreens. Amaxand LA showed similar, but less consistent associations with phenotypic plasticity. Our results show the potential of building predictive frameworks for phenotypic plasticity based on easily measured plant functional characteristics. Results also provide insights into plant strategies and suggest the existence of potential compromises: resource-conservative, low-SLA species tend to be more stress-tolerant but may be less able to cope with variable conditions due to their generally lower phenotypic plasticity. Further studies are needed to explore the mechanisms and the potential implications of this association.GCS was supported by ANID through the FONDECYT IniciaciĂłn grant 11220233. EG was funded by FONDECYT grant 1180334.Peer reviewe
Global trends in phenotypic plasticity of plants
Predicting plastic responses is crucial to assess plant species potential to adapt to climate change, but little is known about which factors drive the biogeographical patterns of phenotypic plasticity in plants. Theory predicts that climatic variability would select for increased phenotypic plasticity, whereas evidence indicates
that stressful conditions can limit phenotypic plasticity. Using a meta- analytic, phylogeny- corrected approach to global data on plant phenotypic plasticity, we tested whether latitude, climate, climatic variability and/or stressful conditions are predictors of plastic responses at a biogeographical scale. We found support for
a positive association between phenotypic plasticity and climatic variability only for plasticity in allocation. Plasticity in leaf morphology, size and physiology were positively associated with mean annual temperature. We also found evidence that phenotypic plasticity in physiology is limited by cold stress. Overall, plant plastic
responses to non- climatic factors were stronger than responses to climatic factors. However, while climatic conditions were associated with plant plastic responses to climatic factors, they generally did not relate to plastic responses to other abiotic or biotic factors. Our study highlights the need to consider those factors that favour and limit phenotypic plasticity in order to improve predictive frameworks addressing plant speciesâ potential to adapt to climate change.Peer reviewe
Trends in Antarctic ecological research in Latin America shown by publications in international journals
Antarctica is a highly interesting region for ecologists because of its extreme climatic conditions and the uniqueness of its species. In this article, we describe the trends in Antarctic ecological research participation by Latin American countries. In a survey of articles indexed by the ISI Web of Science, we searched under the categories ââEcology,ââ ââBiodiversity Conservationââ and ââEvolutionary Biologyââ and found a total of 254 research articles published by Latin American countries. We classified these articles according to the country of affiliation, kingdom of the study species, level of biological organization and environment. Our main finding is that there is a steady increase in the relative contribution of Latin American countries to Antarctic ecological research. Within each category, we found that marine studies are more common than terrestrial studies. Between the different kingdoms, most studies focus on animals and most studies use a community approach. The leading countries in terms of productivity were Argentina, Chile and Brazil, with Argentina showing the highest rate of increase.Keywords: Antarctica; Argentina; Brazil; Chile; research trends; scientific productivity(Published: 17 September 2013)Citation: Polar Research 2013, 32, 19993, http://dx.doi.org/10.3402/polar.v32i0.1999
Efeito de Brachiaria decumbens na herbivoria e no desenvolvimento de duas leguminosas nativas de cerrado Effect of Brachiaria decumbens on herbivory and development of two cerrado native leguminosae species
Este estudo avaliou o impacto da presença da gramĂnea exĂłtica (Brachiaria decumbens) na herbivoria e no desenvolvimento de plĂąntulas de espĂ©cies nativas (Hymenaea stigonocarpa e Dipteryx alata) de Cerrado. Para avaliar o impacto da presença da gramĂnea, 10 blocos em pastagem (antiga ĂĄrea de Cerrado) na Embrapa Gado de Corte (Campo Grande-MS) foram demarcados em janeiro de 2009. As gramĂneas foram mantidas intactas em metade dos blocos e, na outra metade, foram removidas. Em cada tratamento, foram avaliados a herbivoria, a altura e o diĂąmetro na altura do solo (DAS) de 25 plĂąntulas de cada espĂ©cie ao longo do ano. O conteĂșdo de carbono, nitrogĂȘnio e ĂĄgua das folhas tambĂ©m foi quantificado. PlĂąntulas de Hymenaea stigonocarpa nos tratamentos com gramĂnea tiveram maior taxa de crescimento em diĂąmetro que as plĂąntulas no tratamento sem gramĂneas. As plĂąntulas de Dipteryx alata que estavam no tratamento sem gramĂneas tiveram maiores taxas de crescimento em altura que as do tratamento com gramĂneas. Houve diferença na taxa de herbivoria de D.alata entre os tratamentos. As plĂąntulas das duas espĂ©cies que estavam no tratamento com gramĂnea mostraram maiores concentraçÔes de carbono e menores de ĂĄgua. O conteĂșdo de nitrogĂȘnio foliar foi maior no tratamento com gramĂneas que no sem gramĂneas em D.alata; jĂĄ o nitrogĂȘnio em H. stigonocarpa nĂŁo variou entre os tratamentos. Esses resultados mostram que cada espĂ©cie nativa possui distintas respostas fisiolĂłgicas e suscetibilidade Ă herbivoria em ambientes sob competição de recursos com a gramĂnea exĂłtica, B. decumbens.<br>This study evaluated the impact of the presence of the exotic grass (Brachiaria decumbens) on the herbivory and development of seedlings of native species (Hymenaea stigonocarpa and Dipteryx alata) of the Cerrado. Thus, 10 pasture plots (former Cerrado) at the Embrapa Gado de Corte (Campo Grande-MS) were demarcated in January 2009. The grasses were kept intact in half of the plots and were removed in the other half. In each treatment, the herbivory, as well as height and diameter at ground level (DGL) of 25seedlings of each species were evaluated during one year. Carbon, nitrogen and water content of the leaves in each treatment were also quantified. Seedlings of Hymenaea stigonocarpa in plots without grasses had higher diameter growth rates than seedlings in plots with grasses. Dipteryx alata seedlings grown in plots without grasses had a higher height growth rate than seedlings grown in plots with grasses. There was a difference in the herbivory rate of D. alata between treatments. Seedlings of plots with grasses for the two species showed a higher concentration of carbon and lower amount of water. The leaf nitrogen content was higher in plots with grasses than without grasses in D. alata, while nitrogen in H. stigonocarpa did not vary between treatments. These results showed that each native species had distinct physiological responses and susceptibility to herbivory in environments under resource competition with the exotic grass B. decumbens
Patterns of herbivore damage, developmental stability, morphological and biochemical traits in female and male Mercurialis perennis in contrasting light habitats
Phenolics lie at the centre of functional versatility in the responses of two phytochemically diverse tropical trees to canopy thinning
Trends in Antarctic ecological research in Latin America shown by publications in international journals
Antarctica is a highly interesting region for ecologists because of its extreme climatic conditions and the uniqueness of its species. In this article, we describe the trends in Antarctic ecological research participation by Latin American countries. In a survey of articles indexed by the ISI Web of Science, we searched under the categories “Ecology,” “Biodiversity Conservation” and “Evolutionary Biology” and found a total of 254 research articles published by Latin American countries. We classified these articles according to the country of affiliation, kingdom of the study species, level of biological organization and environment. Our main finding is that there is a steady increase in the relative contribution of Latin American countries to Antarctic ecological research. Within each category, we found that marine studies are more common than terrestrial studies. Between the different kingdoms, most studies focus on animals and most studies use a community approach. The leading countries in terms of productivity were Argentina, Chile and Brazil, with Argentina showing the highest rate of increase