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

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.

Download Full-text

Assessing water demand with remote sensing for two coriander varieties

Agronomía Colombiana ◽

10.15446/agron.colomb.v36n3.71809 ◽

2018 ◽

Vol 36 (3) ◽

pp. 266-273

Author(s):

Euseppe Ortiz ◽

Enrique A. Torres

Keyword(s):

Remote Sensing ◽

Water Balance ◽

Water Demand ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Digital Camera ◽

Crop Coefficient ◽

Remote Sensors ◽

The Relationship ◽

Important Basis

The use of remote sensing to determine water needs has been successfully applied by several authors to different crops, maintaining, as an important basis, the relationship between the normalized difference vegetation index (NDVI) and biophysical variables, such as the fraction of coverage (fc) and the basal crop coefficient (Kcb). Therefore, this study quantified the water needs of two varieties of coriander (UNAPAL Laurena CL and UNAPAL Precoso CP) based on the response of fc and Kcb, using remote sensors and a water balance according to the FAO-56 methodology. A Campbell Scientific meteorological station, a commercial digital camera and a portable spectro radiometer were used to obtain information on the environmental conditions and the crop. By means of remote sensing associated with a water balance, it was found that the water demand was 156 mm for CL and 151 mm for CP until the foliage harvest (41 d after sowing); additionally, the initial Kcb was 0.14, the mean Kcb was 1.16 (approximately) and the final Kcb was 0.71 (approximately).

Download Full-text

A PAISAGEM COMO CONDICIONADORA DE BORDAS DE FRAGMENTOS FLORESTAIS

FLORESTA ◽

10.5380/rf.v35i1.2427 ◽

2005 ◽

Vol 35 (1) ◽

Cited By ~ 7

Author(s):

Bethania Cristiane Herrmann ◽

Efraim Rodrigues ◽

André De Lima

Keyword(s):

Species Composition ◽

Patch Size ◽

Nearest Neighbor ◽

Core Area ◽

Forest Fragments ◽

Spatial Structures ◽

Landscape Index ◽

Area Index ◽

Components Analysis ◽

The Relationship

Fragmentos florestais diferem em sua estrutura espacial afetando a composição de espécies em suas bordas. O objetivo deste trabalho foi analisar a influência dos índices da paisagem sobre as bordas de fragmentos florestais próximos à cidade de Londrina - PR. As características estruturais dos fragmentos aqui consideradas incluem área, forma, área central e índice de área central; e as características estruturais da paisagem: área da classe, tamanho médio e coeficiente de variação do tamanho dos fragmentos de floresta, distância média até o fragmento florestal mais próximo e total de bordas de floresta. A relação entre composição de espécies, fragmentos florestais e índices de paisagem foi estudada através de Análise de Correspondência Canônica. Os índices de maior importância foram: área, forma e área central dos fragmentos. Godoy, fragmento com 2371,14 ha e inclui o Parque Estadual Mata dos Godoy, apresentou maior variação na composição de espécies quando comparado com os demais. The landscape as conditioning of edges of forest fragments Abstract Forests fragments differ in their spatial structure afecting the species composition of edges. The objective of this paper was to analyze the influence of some landscape index over sapling species composition in edges of forests fragments near Londrina - PR. The spatial structures of fragments considered in this paper involved area, shape, core area and core area index; and the spatial structures of landscape: class area, mean patch size, coefficient of variation of the size of the patch (%), mean nearest neighbor distance and total edge of forest. The relationship between sapling species composition, forests fragments and landscape index were evaluated through Principal Components Analysis. Godoy, fragment with 2371,14 ha showed more variation in the species composition when compared with other fragments.

Download Full-text

The validation of a model estimating the Leaf Area Index of grasslands in southern China

The Rangeland Journal ◽

10.1071/rj12025 ◽

2013 ◽

Vol 35 (3) ◽

pp. 245 ◽

Cited By ~ 1

Author(s):

Chengming Sun ◽

Zhengguo Sun ◽

Tao Liu ◽

Doudou Guo ◽

Shaojie Mu ◽

...

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Vegetation Index ◽

Mean Squared Error ◽

Southern China ◽

Carbon Sink ◽

Measurement Data ◽

Light Transmittance ◽

Area Index ◽

Normalised Difference Vegetation Index

In order to estimate the leaf area index (LAI) over large areas in southern China, this paper analysed the relationships between normalised difference vegetation index (NDVI) and the vegetation light transmittance and the extinction coefficient based on the use of moderate resolution imaging spectroradiometer data. By using the improved Beer–Lambert Law, a model was constructed to estimate the LAI in the grassy mountains and slopes of southern China with NDVI as the independent variable. The model was validated with field measurement data from different locations and different years in the grassland mountains and slopes of southern China. The results showed that there was a good correlation between the simulated and observed LAI values, and the values of R2 achieved were high. The relative root mean squared error was between 0.109 and 0.12. This indicated that the model was reliable. The above results provided the theoretical basis for the effective management of the grassland resources in southern China and the effective estimation of grassland carbon sink.

Download Full-text

Monitoring leaf area index at watershed level through NDVI from Landsat-7/ETM+ data

Scientia Agricola ◽

10.1590/s0103-90162004000300001 ◽

2004 ◽

Vol 61 (3) ◽

pp. 243-252 ◽

Cited By ~ 16

Author(s):

Alexandre Cândido Xavier ◽

Carlos Alberto Vettorazzi

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Vegetation Index ◽

Hydrological Cycle ◽

Riparian Forest ◽

Empirical Relationships ◽

Area Index ◽

Landsat 7 ◽

The Mean ◽

The Relationship

Leaf area index (LAI) is an important parameter of the vegetation canopy, and is used, for instance, to estimate evapotranspiration, an important component of the hydrological cycle. This work analyzed the relationship between LAI, measured in field, and NDVI from four dates (derived from Landsat-7/ETM+ data), and with such vegetation index, to generate and analyze LAI maps of the study area for the diverse dates. LAI data were collected monthly in the field with LAI-2000 equipment in stands of sugar cane, pasture, corn, eucalypt, and riparian forest. The relationships between LAI and NDVI were adjusted by a potential model; 57% to 72% of the NDVI variance were explained by the LAI. LAI maps generated by empirical relationships between LAI and NDVI showed reasonable precision (standard error of LAI estimate ranged from 0.42 to 0.87 m² m-2). The mean LAI value of each monthly LAI map was shown to be related to the total precipitation in the three previous months.

Download Full-text

Measuring A Fire: The Story of the January 2019 Fire Told from Measurements at the Warra Supersite, Tasmania

Fire ◽

10.3390/fire4020015 ◽

2021 ◽

Vol 4 (2) ◽

pp. 15

Author(s):

Tim Wardlaw

Keyword(s):

Vegetation Change ◽

Carbon Sink ◽

Natural Disturbance ◽

Weather Conditions ◽

Permanent Plots ◽

Ground Vegetation ◽

Area Index ◽

Forest Fire Danger ◽

Eucalypt Forests ◽

Fine Fuels

Non-stand-replacing wildfires are the most common natural disturbance in the tall eucalypt forests of Tasmania, yet little is known about the conditions under which these fires burn and the effects they have on the forest. A dry lightning storm in January 2019 initiated the Riveaux Road fire. This fire burnt nearly 64,000 ha of land, including tall eucalypt forests at the Warra Supersite. At the Supersite, the passage of the fire was recorded by a suite of instruments measuring weather conditions and fluxes (carbon, water and energy), while a network of permanent plots measured vegetation change. Weather conditions in the lead-up and during the passage of the fire through the Supersite were mild—a moderate forest fire danger index. The passage of the fire through the Supersite caused a short peak in air temperature coinciding with a sharp rise in CO2 emissions. Fine fuels and ground vegetation were consumed but the low intensity fire only scorched the understorey trees, which subsequently died and left the Eucalyptus obliqua canopy largely intact. In the aftermath of the fire, there was prolific seedling regeneration, a sustained reduction in leaf area index, and the forest switched from being a carbon sink before the fire to becoming a carbon source during the first post-fire growing season.

Download Full-text

The relationship between effective plant area index and Landsat spectral response across elevation, solar insolation, and spatial scales in a northern Idaho forest

Canadian Journal of Forest Research ◽

10.1139/x03-215 ◽

2004 ◽

Vol 34 (2) ◽

pp. 465-480 ◽

Cited By ~ 28

Author(s):

Amy L Pocewicz ◽

Paul Gessler ◽

Andrew P Robinson

Keyword(s):

Spatial Scale ◽

Complex Terrain ◽

Vegetation Index ◽

Remotely Sensed ◽

Solar Insolation ◽

Area Index ◽

Plant Area Index ◽

Plant Area ◽

Northern Idaho ◽

The Relationship

Leaf area index (LAI) is an important forest characteristic related to photosynthesis and carbon sequestration, and gains in efficiency for LAI measurements are possible using remotely sensed imagery. However, the potential effects of complex topography on this measurement system are not well understood. Our objective was to understand how complex terrain and measurement aggregation influence the relationship between LAI and remotely sensed vegetation indices across a mountainous conifer forest. We identified NDVIc, a middle-infrared (MIR) correction to NDVI (Normalized Difference Vegetation Index), as the vegetation index providing the best prediction of effective plant area index (PAIe), used to approximate LAI. We tested formal hypotheses to identify how elevation and solar insolation gradients and spatial scale of measurement aggregation affected the PAIeNDVIc relationship and found that it changed across elevation at one spatial scale. Comparisons of NDVIc with NDVI revealed that vegetation index choice is important in complex terrain, and we concluded that the MIR correction improves the PAIeNDVI relationship by explaining variation related to solar insolation. Our results suggest that NDVIc calculated from Landsat ETM+ provides a practical estimate of PAIe across our northern Idaho study area and potentially other conifer forests in complex terrain.

Download Full-text

RELAÇÃO DA MORFOMETRIA E COMPETIÇÃO COM O CRESCIMENTO DE Trichilia claussenii EM UM FRAGMENTO DE FLORESTA SEMIDECIDUAL, RS

FLORESTA ◽

10.5380/rf.v45i2.35164 ◽

2014 ◽

Vol 45 (2) ◽

pp. 373 ◽

Cited By ~ 4

Author(s):

Bruna Denardin Da Silveira ◽

Eduardo Pagel Floriano ◽

Nelson Yoshihiro Nakajima ◽

Roberto Tuyoshi Hosokawa ◽

Nelson Carlos Rosot ◽

...

Keyword(s):

Pearson Correlation ◽

Rio Grande ◽

Permanent Plots ◽

Native Forest ◽

Rio Grande Do Sul ◽

Semideciduous Forest ◽

Diameter At Breast Height ◽

Diameter Increment ◽

Breast Height ◽

The Relationship

Este trabalho teve como objetivos determinar a relação de variáveis morfométricas e de índices de competição com o crescimento em diâmetro de Trichilia claussenii, em um fragmento da Floresta Estacional Semidecidual na região central do Rio Grande do Sul. Os dados utilizados neste estudo foram obtidos de 29 árvores amostradas por classe diamétrica, denominadas árvores centrais, com diâmetro à altura do peito (d) igual ou superior a 10,0 centímetros, distribuídas em 51 parcelas permanentes, totalizando 0,51 hectares. Cada árvore central teve as seguintes variáveis mensuradas: altura total e altura comercial do fuste, diâmetro à altura do peito, diâmetro da copa e comprimento de copa. Posteriormente, calcularam-se alguns parâmetros morfométricos, assim como alguns índices de competição dependentes e independentes da distância. A análise de correlação de Pearson e análise de regressão foram utilizadas para verificar a relação entre as variáveis morfométricas, os índices de competição e o incremento em diâmetro. Concluiu-se que existe associação entre o incremento em diâmetro de Trichilia claussenii e a competição, sendo que o crescimento em diâmetro possui maior relação com o índice Bal de competição.Palavras-chave: Catiguá; floresta nativa; biometria florestal. AbstractRelationship of morphometry and competition with growth of Trichilia claussenii in fragment of Semidecidual Forest, RS. This study aimed to determine the relationship of morphometric variables and indices of competition with the growth in diameter of Trichilia claussenii, in a fragment of semideciduous forest in the central region of Rio Grande do Sul. The data used in this study were obtained from 29 sampled trees by diameter class, called central trees with diameter at breast height (d) not less than 10.0 cm, from 51 permanent plots, totaling 0.51 ha. Each central tree had measured the following variables: total height and commercial height, stem diameter at breast height, crown diameter and crown length. Subsequently, it was calculated some morphometric parameters, as well as some competition indexes dependent and independent of distance. The Pearson correlation analysis and regression analysis were used to verify the relationship between the morphometric variables, competition indexes and diameter increment. It was concluded that there is an association between the increase in diameter of Trichilia claussenii and competition, where the growth in diameter has a greater relationship with Bal index of competition.Keywords: Catigua; native forest; forest biometrics.

Download Full-text

Biomass and vegetation index by remote sensing in different caatinga forest areas

Ciência Rural ◽

10.1590/0103-8478cr20201104 ◽

2022 ◽

Vol 52 (2) ◽

Author(s):

Leudiane Rodrigues Luz ◽

Vanderlise Giongo ◽

Antonio Marcos dos Santos ◽

Rodrigo José de Carvalho Lopes ◽

Claudemiro de Lima Júnior

Keyword(s):

Aboveground Biomass ◽

Vegetation Index ◽

Correlation Coefficients ◽

Absolute Error ◽

Allometric Equations ◽

Coefficient Of Determination ◽

Forest Fragments ◽

Vegetation Indexes ◽

Landscape Transformations ◽

The Relationship

ABSTRACT: Continued unsustainable exploitation of natural resources promotes environmental degradation and threatens the preservation of dry forests around the world. This situation exposes the fragility and the necessity to study landscape transformations. In addition, it is necessary to consider the biomass quantity and to establish strategies to monitor natural and anthropic disturbances. Thus, this research analyzed the relationship between vegetation index and the estimated biomass using allometric equations in different Brazilian caatinga forest areas from satellite images. This procedure is performed by estimating the biomass from 9 dry tropical forest fragments using allometric equations. Area delimitations were obtained from the Embrapa collection of dendrometric data collected in the period between 2011 and 2012. Spectral variables were obtained from the orthorectified images of the RapidEye satellite. The aboveground biomass ranged from 6.88 to 123.82 Mg.ha-1. SAVI values were L = 1 and L = 0.5, while NDVI and EVI ranged from 0.1835 to 0.4294, 0.2197 to 0.5019, 0.3622 to 0.7584, and 0.0987 to 0.3169, respectively. Relationships among the estimated biomass and the vegetation indexes were moderate, with correlation coefficients (Rs) varying between 0.64 and 0.58. The best adjusted equation was the SAVI equation, for which the coefficient of determination was R² = 0.50, R2aj = 0.49, RMSE = 17.18 Mg.ha-1 and mean absolute error of prediction (MAE) = 14.07 Mg.ha-1, confirming the importance of the Savi index in estimating the caatinga aboveground biomass.

Download Full-text

HEALTHINESS OF OIL PALM PLANTATION TOWARDS SUSTAINABILITY OF ENVIRONMENT

Malaysian Journal of Sustainable Environment ◽

10.24191/myse.v7i1.8905 ◽

2020 ◽

Vol 7 (1) ◽

pp. 21

Author(s):

Faradina Marzukhi ◽

Nur Nadhirah Rusyda Rosnan ◽

Md Azlin Md Said

Keyword(s):

Oil Palm ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Satellite Image ◽

Vegetation Indices ◽

Soil Nutrient ◽

Oil Palm Plantation ◽

Sustainable Environment ◽

Moisture Analysis ◽

The Relationship

The aim of this study is to analyse the relationship between vegetation indices of Normalized Difference Vegetation Index (NDVI) and soil nutrient of oil palm plantation at Felcra Nasaruddin Bota in Perak for future sustainable environment. The satellite image was used and processed in the research. By Using NDVI, the vegetation index was obtained which varies from -1 to +1. Then, the soil sample and soil moisture analysis were carried in order to identify the nutrient values of Nitrogen (N), Phosphorus (P) and Potassium (K). A total of seven soil samples were acquired within the oil palm plantation area. A regression model was then made between physical condition of the oil palms and soil nutrients for determining the strength of the relationship. It is hoped that the risk map of oil palm healthiness can be produced for various applications which are related to agricultural plantation.

Download Full-text

Optimizing Grain Yield and Water Use Efficiency Based on the Relationship between Leaf Area Index and Evapotranspiration

Agriculture ◽

10.3390/agriculture11040313 ◽

2021 ◽

Vol 11 (4) ◽

pp. 313

Author(s):

Guoqiang Zhang ◽

Bo Ming ◽

Dongping Shen ◽

Ruizhi Xie ◽

Peng Hou ◽

...

Keyword(s):

Grain Yield ◽

Water Use Efficiency ◽

Leaf Area Index ◽

Water Use ◽

Plant Density ◽

Maize Yield ◽

Area Index ◽

Irrigation Level ◽

Use Efficiency ◽

The Relationship

Achieving optimal balance between maize yield and water use efficiency is an important challenge for irrigation maize production in arid areas. In this study, we conducted an experiment in Xinjiang China in 2016 and 2017 to quantify the response of maize yield and water use to plant density and irrigation schedules. The treatments included four irrigation levels: 360 (W1), 480 (W2), 600 (W3), and 720 mm (W4), and five plant densities: 7.5 (D1), 9.0 (D2), 10.5 (D3), 12.0 (D4), and 13.5 plants m−2 (D5). The results showed that increasing the plant density and the irrigation level could both significantly increase the leaf area index (LAI). However, LAI expansion significantly increased evapotranspiration (ETa) under irrigation. The combination of irrigation level 600 mm (W3) and plant density 12.0 plants m−2 (D4) produced the highest maize yield (21.0–21.2 t ha−1), ETa (784.1–797.8 mm), and water use efficiency (WUE) (2.64–2.70 kg m−3), with an LAI of 8.5–8.7 at the silking stage. The relationship between LAI and grain yield and evapotranspiration were quantified, and, based on this, the relationship between water use and maize productivity was analyzed. Moreover, the optimal LAI was established to determine the reasonable irrigation level and coordinate the relationship between the increase in grain yield and the decrease in water use efficiency.

Download Full-text