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The positive balance between inputs/outputs of carbon in wooded pastures may be associated with soil physical-hydric attributes. These relationships are not totally known. This study aims to examine the relation between soil physical-hydric parameters with balance between primary production (carbon input) and soil respiration (carbon output). The study was carried out in three grazing systems: A Urochloa mosambicensis grass pasture (LU1), a silvopastoral system with U. mosambicensis and tree legume (LU2), and an area with U. mosambicensis and a herbaceous legume (LU3). The soil CO2 efflux (ECO2) and ten indicators of soil physical-hydric quality were measured: macroporosity, aeration capacity, plant-available water capacity (PAWC), relative field capacity (RFC), characteristic pore radius, quantity of hydraulically active pores, sorptivity, saturated hydraulic conductivity, soil bulk density, and soil penetration resistance. The leaf area index was used as an indicator of forage production. In the dry period, LU2 had averages of 0.17 m3 m−3 (PAWC) and 0.63 (RFC), while LU1 and LU3 both had an PAWC of 0.14 m3 m−3 and RFC of 0.54 and 0.57, respectively. This study provides the first evidence that soil physical-hydric attributes, specifically the plant-available water capacity and the connectivity of pores with wooded pastures, in semi-arid regions, favors a positive carbon balance in these systems (higher input/lower output). [ABSTRACT FROM AUTHOR]

This article presents a study on the spatiotemporal dynamics of land cover and use, vegetation indices, and water content in the semiarid region of Pernambuco, Brazil. This study is based on an analysis of satellite images from the years 2016, 2018, and 2019 using the MapBiomas platform. The results show changes in the predominant land cover classes over time, with an increase in the caatinga area and a decrease in the pasture area. An analysis of the vegetation indices (NDVI and LAI) indicated low vegetation cover and biomass in the study area, with a slight increase in the NDVI in 2018. An analysis of the Modified Normalized Difference Water Index (MNDWI) showed that the water content in the study area was generally low, with no significant variations over time. An increase in the water bodies, mainly due to the construction of a reservoir, was noted. The results of this study have provided important information for natural resource management in the region, including the development of strategies for the sustainable use and management of natural resources, particularly water resources, vegetation cover, and soil conservation. [ABSTRACT FROM AUTHOR]

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The watershed are units controlling hydrological processes and essential for implementation of water resources management policies. The present study aims to integrate the morphometry and land use of the Pajeú river Basin and the Boa Vista micro-basin (headwater of the Pajeú river) using satellite data and a set of remote sensing techniques in open-source software (QGIS). The studied areas are in the semi-arid region of the Pernambuco State, Brazil. Physical morphometric parameters (area, perimeter, axial length, compactness factor, form factor, elongation ratio, and circularity ratio), hydrological parameters (length and distribution of the drainage network, drainage density, hydrographic density, constant of channel maintenance, textural ratio, sinuosity, concentration time, and extension of surface course) and relief (slope and altitude map) were produced. Furthermore, in the micro-basin, we determined the distribution of surface reservoirs using the Modified Normalized Difference Water Index (MNDWI). The Pajeú river basin and the micro-basin have an elongated shape (form factor <0.4 and a capacity coefficient greater than 1.8), approximately 65% of areas with a slope of less than 8%, and moderately developed drainage network; thus, the regions studied are not prone to flooding. However, more than 70% of the basin has soils that have a low infiltration capacity, which, when associated with the conditions of removal of native vegetation, tends to favor the occurrence of floods. Through the integration of land use and morphometry, we found that about 40% of the areas that should be riparian forests are under agricultural activities. A more detailed analysis of the morphometry-coverage-soil-hydrology interactions in watersheds helps understand the hydrological processes and basin management. The presented results can be useful for modeling studies in the basin and for future water resources management plans. • Morphometric characteristics and GIS help in watershed management. • The Pajeú river basin and the Boa Vista micro-basin have a low risk of flooding. • MNDWI with Sentinel-2 data is efficient in identifying small surface reservoirs. • Native vegetation (69%) and agriculture (29%) make up areas of the Pajeú basins. • Integrating morphometric/land cover allows for identifying areas for preservation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multivariate analysis assisted to plan the cultivation of forage cactus. • Irrigation affects growth dynamics and forage accumulation of forage cactus. • Growth dynamics and forage accumulation are affected by the semiarid climate. • Opuntia stricta Haw. (Haw.) is more sensitive to semiarid climatic conditions. Comprehending the relation between climatic variables and the productive and morphological characteristics of the forage cactus is essential to the adjustment of the management of its production in different agro-climatic areas. The aim of this study was to evaluate the interrelationship between the meteorological variables and the water regime with the growth dynamics and accumulation of forage mass of three different forage cactus clones. We submitted the clones Miúda–MIU; Orelha de Elefante Mexicana–OEM and IPA Sertânia–IPA to three water regimes (40 %ETc, 80 %ETc and 120 %ETc), plus the non-irrigated condition (0 %ETc), during 18 months, in the municipality of Serra Talhada, Pernambuco, Brazil. Morphological, structural, and productive characteristics of the plants, and environmental variables were supervised throughout the experimental period. Pearson's correlation, multicollinearity test, canonical correlation and path analysis were applied to these data. It was observed that the minimum air temperature, the relative air humidity, and the irrigation were the variables that affected the growth dynamics and the accumulation of fodder mass of the forage cactus clones the most. The clone OEM presented more sensitivity to the environmental conditions (climate and irrigation) in comparison to the other clones MIU and IPA. The environmental conditions affected the growth dynamics more than the productivity of the clone from the genus Nopalea. It was determined that the species of forage cactus presented differentiated morphological and productive responses among themselves, under semiarid conditions in Brazil. [ABSTRACT FROM AUTHOR]