scholarly journals Spatio-Temporal Response of Vegetation Indices to Rainfall and Temperature in A Semiarid Region

2020 ◽  
Vol 12 (5) ◽  
pp. 1939 ◽  
Author(s):  
Edith Olmos-Trujillo ◽  
Julián González-Trinidad ◽  
Hugo Júnez-Ferreira ◽  
Anuard Pacheco-Guerrero ◽  
Carlos Bautista-Capetillo ◽  
...  

In this research, vegetation indices (VIs) were analyzed as indicators of the spatio-temporal variation of vegetation in a semi-arid region. For a better understanding of this dynamic, interactions between vegetation and climate should be studied more widely. To this end, the following methodology was proposed: (1) acquire the NDVI, EVI, SAVI, MSAVI, and NDMI by classification of vegetation and land cover categories in a monthly period from 2014 to 2018; (2) perform a geostatistical analysis of rainfall and temperature; and (3) assess the application of ordinary and uncertainty least squares linear regression models to experimental data from the response of vegetation indices to climatic variables through the BiDASys (bivariate data analysis system) program. The proposed methodology was tested in a semi-arid region of Zacatecas, Mexico. It was found that besides the high values in the indices that indicate good health, the climatic variables that have an impact on the study area should be considered given the close relationship with the vegetation. A better correlation of the NDMI and EVI with rainfall and temperature was found, and similarly, the relationship between VIs and climatic factors showed a general time lag effect. This methodology can be considered in management and conservation plans of natural ecosystems, in the context of climate change and sustainable development policies.

2015 ◽  
Vol 8 ◽  
pp. 510
Author(s):  
Iêdo Bezerra Sá ◽  
Tony Jarbas Ferreira Cunha ◽  
Tatiana Ayako Taura ◽  
Marcos Antônio Drumond

Na região Semiárida do Estado de Pernambuco existe grande diversidade na paisagem natural, onde a vegetação, os solos e o clima geram uma multiplicidade de situações que concorrem para formação de diferentes ecossistemas e habitats com grande potencial ecológico e ambiental. Nesta região, a vegetação é caracterizada por diferentes fisionomias, variando de áreas com formações arbustivas, com cobertura do solo muito escassa e quase ausente, a formações arbóreas com níveis de cobertura bastante densas. De modo análogo, nesta região ocorre uma grande variedade de solos, que por suas características, manejo e situação no relevo podem potencializar os processos erosivos, determinantes no desencadeamento da desertificação. Considerando as interrelações destas duas variáveis ambientais, este trabalho tem o objetivo de realizar um diagnóstico das áreas susceptíveis à desertificação da Região de Desenvolvimento Sertão do São Francisco - RDSF, tendo como base o cruzamento das informações da cobertura vegetal natural e das classes de solos. Para tanto, foram utilizados o recorte do mapeamento da cobertura vegetal e uso do solo e o recorte do mapeamento de solos da RDSF. Foram estabelecidos critérios para susceptibilidade da cobertura vegetal, assim como para as classes de solos presentes na área. Executou-se a intersecção destas duas bases de informação para o perfil da sensibilidade à desertificação. Os resultados mostram que a RDSF tem os seguintes valores das áreas em processos de desertificação: 1,77% na classe ausente ou fraca; 74,74% na classe moderada; 0,35% na classe acentuada e 23,14% na classe severa. Deste modo, observa-se que aproximadamente 98% da RDSF encontram-se na situação de sensibilidade à desertificação em que predominam as classes de Moderada a Severa. In the semiarid region of the state of Pernambuco there are plenty of biophysics where vegetation, climate, soils, and the various faces and the relationships and processes that take place among them generate the formation of different ecosystems and habitats with great potential ecological and environmental. There are a range of vegetation types, ranging from shrubby coverage areas up to very sparse and mostly absent vegetation areas, which demonstrated high desertification process occurring. Similarly, a variety of soils that is in the region along with vegetation makes this a region of great variation from the viewpoint of environmental supply. This article deals with the realization of a diagnosis of environmental sensitivity to desertification of São Francisco Development Region seeking spatialize the different situations in which the environment fulfills a greater or lesser extent, its role as provider of environmental services. For this, we used the cutting mapping of existing vegetation and soil mapping of the state and the established criteria, as well as edaphic vegetation cover, featuring the susceptibility to degradation and performed the intersection of these two bases of information to profile the sensitivity to desertification. The results show that São Francisco Development Region has the following values of areas undergoing desertification: 1.77% in weak class; 74.74% in the moderate class; 0.35% in sharp class, and 23.14% in severe class. Keywords: desertification, São Francisco, Semi-arid region, soils.   


2020 ◽  
Author(s):  
Santosh K Aryal ◽  
Richard P Silberstein ◽  
Guobin Fu ◽  
Geoff Hodgson ◽  
Stephen P Charles ◽  
...  

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 136-142 ◽  
Author(s):  
Aslan Hasan ◽  
Gayberi Mahmut ◽  
Kahraman Abdullah

Pod shattering in lentil which is vital plant of dry lands is a crucial feature for high yield. Selection of lentil variety is very important in order to reduce pod shatter. Some of lentil varieties are very productive; however, shattering loss decreases profitable yields. In this study, reduction of pod shatter in lentil varieties was investigated with application of polymer cyclohexane compounds. An experiment was conducted with split-split-plot experiment design with two lentil varieties (‘Firat-87’ and ‘Cagil’), two application time (podset and 15 days before harvest (DBH)) and three application doses (0, 0.5, 2 l·ha<sup>–1</sup>) as triplicate during two years. Effects of application time on podset were found statistically insignificant and application of 0.5 l·ha<sup>–1</sup> dose was found effective for 15 DBH application time. As a result, 0.5 pod shatter polymer cyclohexane and 15 DBH was found as optimum doses and application time, respectively in order to reduce pod shatter loss by nearly 1% for semiarid region of Turkey.


Author(s):  
Padam Jee Omar ◽  
Nitesh Gupta ◽  
Ravi Prakash Tripathi ◽  
Shiwanshu Shekhar ◽  
Surender .

The relative evaluation of land use and land cover for various uses such as forest, agriculture and water bodies etc. is the important issue in the semiarid region. Application of Remote Sensing technology for Land Use and Land Cover (LULC) change analysis has been carried out in semi-arid region of Madhya Pradesh, central part of India and found that the use of remote sensing along with Survey of India toposheets could be used appropriately for LULC mapping. The semi-arid regions are characterized by erratic rainfall and high rate of vegetation dynamics. The increasing biotic pressure together with increasing human demands exerts pressure on the available land resources all over the region. Therefore, in order to have best possible use of land, it is not only necessary to have the information on the existing LULC, but also to monitor the dynamic land use resulting because of increasing demands aroused from the growing population. Continuous overexploitation of natural resources like land, water, and forest has caused serious threat to the local population of the semi-arid region. This causes problems like little scope for soil moisture storage, high rate of soil erosion, declining groundwater level and shortage of drinking water


2018 ◽  
Vol 55 (4) ◽  
pp. 281-285
Author(s):  
E. F. Fernandes De Carvalho ◽  
A. Ferreira Da Silva-Neta ◽  
C. De Sousa Silva ◽  
C. R. De Oliveira ◽  
J. Da Cunha Xavier Nunes ◽  
...  

Abstract Snakes have diverse feeding and living habits, being exposed to a variety of endoparasite communities. However, more studies are still necessary to document these relationships. We examined 18 specimens of the cat-eyed snake Leptodeira annulata from a semi-arid region in Northeast Brazil. Eight taxa of parasites were found, with higher prevalence of cystacanths (Acanthocephala). Five nematode species (Hexametra boddaertii, Oswaldocruzia sp., Oxyascaris sp., Physaloptera sp. and Raillietnema spectans) and the pentastome Raillietiella furcocerca represent a new parasitism record for the host studied. Our results also showed that L. annulata could act as paratenic host for acanthocephalans. These results contribute to the knowledge of the helminth fauna of L. annulata.


2021 ◽  
Vol 13 (21) ◽  
pp. 4246
Author(s):  
Zhenzong Wu ◽  
Jian Bi ◽  
Yifei Gao

The dynamics of terrestrial vegetation have changed a lot due to climate change and direct human interference. Monitoring these changes and understanding the mechanisms driving them are important for better understanding and projecting the Earth system. Here, we assessed the dynamics of vegetation in a semi-arid region of Northwest China for the years from 2000 to 2019 through satellite remote sensing using Vegetation Index (VI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS), and analyzed the interannual covariation between vegetation and three climatic factors—air temperature, precipitation, and vapor pressure deficit (VPD)—at nine meteorological stations. The main findings of this research are: (1) herbaceous land greened up much more than forests (2.85%/year vs. 1.26%/year) in this semi-arid region; (2) the magnitudes of green-up for croplands and grasslands were very similar, suggesting that agricultural practices, such as fertilization and irrigation, might have contributed little to vegetation green-up in this semi-arid region; and (3) the interannual dynamics of vegetation at high altitudes in this region correlate little with temperature, precipitation, or VPD, suggesting that factors other than temperature and moisture control the interannual vegetation dynamics there.


Author(s):  
Maria da Conceição de Sousa ◽  
Gustavo Vieira Veloso ◽  
Lucas Carvalho Gomes ◽  
Elpidio Inácio Fernandes-Filho ◽  
Teógenes Senna de Oliveira

Phytotaxa ◽  
2018 ◽  
Vol 351 (1) ◽  
pp. 53
Author(s):  
CARLOS A.F. DE SOUZA ◽  
KERSTIN VOIGT ◽  
LUCIANA SARTORI GURGEL ◽  
THALLINE R.L. CORDEIRO ◽  
RAFAEL J.V. OLIVEIRA ◽  
...  

During a survey of Mucorales in fragments of an Atlantic Upland Forest inserted in the semiarid region of Pernambuco, Brazil, a specimen of Mucor was isolated from soil samples. The specimen was characterized based on morphological, physiological and molecular data (ITS and LSU rDNA regions). The isolate produces intensely branched sporangiophores commonly with between one and several septa with mostly applanate columellae. The sporangiophores were smooth-walled and varied in shape and size, while some were subglobose. The best growth was at 25°C but there was also good growth at 30°C. Based on the evidence of the analyzed datasets a new species of Mucor is proposed. A detailed description of the new specimen of Mucor from the Brazilian semi-arid region are provided.


2021 ◽  
Vol 107 ◽  
pp. 103155
Author(s):  
Marcos Vinícius da Silva ◽  
Héliton Pandorfi ◽  
Gledson Luiz Pontes de Almeida ◽  
Renato Paiva de Lima ◽  
Anderson dos Santos ◽  
...  

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