Species Caesalpinia pyramidalis Tul. and Prosopis juliflora Sw (DC.) on different water regimes: growth and mathematical models fitting

Abstract

Poucos são os estudos que destacam o efeito de diferentes regimes hídricos sobre o crescimento de plantas da Caatinga; ao passo que modelos matemáticos empíricos são utilizados em larga escala na modelagem de crescimento de plantas, mas também tem sido pouco aplicados para espécies desse bioma. Objetivou-se avaliar o crescimento inicial e o desempenho de modelos matemáticos no ajuste de dados biométricos e de biomassa de espécies ocorrentes na caatinga sob diferentes regimes hídricos. Um experimento foi conduzido, em condições de viveiro, no município de Serra Talhada, PE, com as espécies Caesalpinia pyramidallis Tul. (catingueira) e Prosopis juliflora Sw (DC.) (algaroba) submetidas a regimes hídricos com base na evapotranspiração de referência (ETo) (50%.ETo, 75%.ETo, 100%.ETo e 125%.ETo). Ao longo do tempo foram feitas medições biométricas e de biomassa nas plantas. Foram testados os modelos de Gompertz, Sigmoidal, Logístico, Chapman e Gaussiano, usando como variáveis independentes, os dias após a semeadura e graus dias acumulados. Os quatro regimes hídricos não exerceram influência na matéria seca da raiz, e não se observou diferenças para o acúmulo de matéria seca das folhas e da planta nas lâminas superiores a 75% de ETo. P. juliflora apresentou maior emissão de folíolos, porém não se diferenciou em área foliar da C pyramidalis. As variáveis biométricas da catingueira e da algaroba foram melhores ajustadas pelo modelo de Gompertz, enquanto os de Chapman e Gaussiano foram os que mais explicaram a variação dos dados de biomassa nos distintos regimes hídricos, utilizando como variável independente os graus dias acumulados. Palavras-chave: algaroba, biometria, biomassa, catingueira, graus dias, modelagem, regressão não linear. Species Caesalpinia pyramidalis Tul. and Prosopis juliflora Sw (DC.) on different water regimes: growth and mathematical models fitting A B S T R A C T Few are the studies that highlight the effect of different water regimes on the plants growth of the Caatinga; while empirical mathematical models are used in a large scale in the modelling of plants growth, but it also has been applied to species of this biome. Objective to evaluate the initial growth and performance of mathematical models in the adjustment of biometric and biomass data of species occurring in the caatinga under different water regimes. An experiment was conducted under conditions of viveiro, in the municipality of Serra Talhada, State of Pernmabuco, with the species Caesalpinia pyramidallis Tul. (catingueira) and Prosopis juliflora Sw (DC.) (algaroba) submitted to water regimes based on the reference evapotranspiration (ETo) (50%.ETo, 75%.ETo, 100%.ETo and 125%.ETo). Over time biometric and biomass measurements in plants were made. The Gompertz, Logistic, Sigmoid, Chapman and Gaussian models were tested, using as independent variables, the days after sowing and degrees days accumulated. The four water regimes do not exerted influence on root dry matter, and was not observed differences for dry matter accumulation of leave...

Partitioning and Modeling of Biomass in Caatinga Legume Seedlings in Different Water Conditions

“…This result indicates that the occurrence of short periods of water deficit (represented by the differentiation of the water regime resupply) did not promote significant changes in the growth of the aerial part dry matter of these species. Silva et al (2015) found different results when analyzed the influence of the water regime on the species Prosopis juliflora Sw (DC.) and Caesalpinia pyramidalis Tul.,…”

“…In the studies on the initial growth of Prosopis juliflora Sw (DC. ), an invasive species and Caesalpinia pyramidalis Tul., a native species, Silva et al (2015) adjusted several physical models, among them, the Gaussian and Gompertz to estimate dry biomass as a function of water availability. These researchers obtained excellent values for the validation parameters R, d, c, MAE and SRMSE, where the Gompertz model excelled with optimal accuracy (d close to 1) using GDA values.…”

“…Brenan are native to the Caatinga Domain and have been used for economic, social and environmental purposes (Lorenzi, 2009). They present rapid growth and one way to understand the responses to environmental stresses is through dry biomass and its directly partitioning (Gonçalves et al, 2013), as well as the mathematical modeling, which can be applied in highly dynamic environments (Pinheiro et al, 2015;Silva et al, 2015).…”

“…The use of the modeling enables an integrated analysis of the biophysical knowledge that governs the soil-plant-atmosphere system, allowing to evaluate the uncertainties associated with environmental modifications. Regarding the semi-arid reality, however, Silva et al (2015) cite that few studies use simulation of native plant growth, unlike other Brazilian morphoclimatic domains. The understanding of responses to water deficit may help the development of strategies for the production of seedlings, conservation of the environment and restoration of native forests in degraded areas.…”