Semideciduous Seasonal Forest Production of Leaves and Deciduousness in Function of the Water Balance, LAI, and NDVI

Thomaz Correa E Castro Da Costa,Juliana Leite Ribeiro,João Herbert Moreira Viana

doi:10.1155/2014/923027

Thomaz Correa E Castro Da Costa, Juliana Leite Ribeiro + Show 1 more

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https://doi.org/10.1155/2014/923027

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Abstract

This study investigated the relationship between leaf production, litterfall, water balance, Leaf Area Index (LAI), and Normalized Difference Vegetation Index (NDVI) in semideciduous forests. The goal was to model this phenomenon to obtain the estimates of this component as an additional compartment of the ecosystem carbon sink. The tests were conducted in eight semideciduous forest fragments. Twenty-four permanent plots were monitored monthly and LAI measurements and weighing of litterfall deposited in nets were conducted for a period of thirteen months. In this period, Landsat 5 and IRS satellite images were obtained and processed for generation of NDVI. The water balance was calculated for each day. The relationship among the variables “leaf dry weight,” “LAI,” “NDVI,” and “water balance” was verified and a regression model was built and evaluated. The deciduous phenomenon can be explained by hydric balance, and LAI and NDVI are ancillary variables. The tendency of the variables in the period of 13 months was explained by quadratic functions. The varied behavior among the monitoring sites helped to know differences in the deposition of leaves. This study showed that only the leaf component of the litterfall of a semideciduous forest in tropical climate can capture 4 to 8 Mg·ha−1·yr−1of CO2and this amount can be estimated using climate, biophysics, and vegetation index variables.

Highlights

The sprouting, development, blooming, fruit bearing, and senescence phases determine the phenology of plant species
Leaf Area Index (LAI) has a strong relationship with the deciduousness in this forest typology, as its value is the consequence of the quantity of leaves in the canopy, so alterations in this quantity directly reflect in the LAI
In larger forest areas, its application may go without LAI measurement in the field. Another observation refers to the LAI calculation from NDVIMODIS, based on the results presented in Figure 5 in Potithep et al [29]

Summary

Introduction

The sprouting, development, blooming, fruit bearing, and senescence phases determine the phenology of plant species. In forest ecosystems, the sprouting and leaf growth, the senescence, and the leaf fall are crucial for their maintenance and for survival through the nutrient cycling. The fall of leaves, branches, flowers, and fruits supplies organic material to the surface layer of the soil nourishing the plant species. By means of this process, nutrients are deposited and mineralized, maintaining the soil fertility in these ecosystems [1,2,3]. The accumulated litterfall is all the deposited material on the surface of the forest soil for a determined period, which may be measured by the deposition in collectors of prefixed sizes during preestablished time intervals [6]

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