Search Results (7)

Epiphytic organisms are characteristic elements of the Andean dry forest, playing a crucial role in ecosystem diversity and functionality, but they are threatened by deforestation-related factors. The diversity of epiphytic lichens and bryophytes was recorded in the Pisaca Reserve, which has an artificial pond locally known as “Laguna Pisaca”, serving as a critical micro-watershed. This pond provides water services to the city of Catacocha, motivating local communities to protect its biodiversity. In each zone (low, middle and high), 10 plots of 5 × 5 m were established, where the presence and coverage of lichens and bryophytes were sampled in 4 trees per plot (120 trees). Richness and diversity (Shannon–Weaver and Simpson indices) were calculated. Generalized linear models (GLM) were used to analyze the effect of the zone on richness and diversity, and multivariate analysis was used to analyze species composition. A total of 90 species were recorded (65 lichens and 25 bryophytes), distributed in three zones: 74 in the high, 67 in the low and 41 in the middle zone. Species richness and composition showed significant variations in relation to the three zones, influenced by forest structure, small altitudinal changes and forests disturbance. The forests of the Pisaca Reserve harbor a great diversity of lichens and epiphytic bryophytes, which serve as refuges for biodiversity in the Andean dry montane forest of South Ecuador. Full article

Recent advancements in Earth Observation sensors, improved accessibility to imagery and the development of corresponding processing tools have significantly empowered researchers to extract insights from Multisource Remote Sensing. This study aims to use these technologies for mapping summer and winter Land Use/Land Cover features in Cuenca de la Laguna Merín, Uruguay, while comparing the performance of Random Forests, Support Vector Machines, and Gradient-Boosting Tree classifiers. The materials include Sentinel-2, Sentinel-1 and Shuttle Radar Topography Mission imagery, Google Earth Engine, training and validation datasets and quoted classifiers. The methods involve creating a multisource database, conducting feature importance analysis, developing models, supervised classification and performing accuracy assessments. Results indicate a low significance of microwave inputs relative to optical features. Short-wave infrared bands and transformations such as the Normalised Vegetation Index, Land Surface Water Index and Enhanced Vegetation Index demonstrate the highest importance. Accuracy assessments indicate that performance in mapping various classes is optimal, particularly for rice paddies, which play a vital role in the country’s economy and highlight significant environmental concerns. However, challenges persist in reducing confusion between classes, particularly regarding natural vegetation features versus seasonally flooded vegetation, as well as post-agricultural fields/bare land and herbaceous areas. Random Forests and Gradient-Boosting Trees exhibited superior performance compared to Support Vector Machines. Future research should explore approaches such as Deep Learning and pixel-based and object-based classification integration to address the identified challenges. These initiatives should consider various data combinations, including additional indices and texture metrics derived from the Grey-Level Co-Occurrence Matrix. Full article

Hydrological region 36 in Mexico (RH36) faces significant water stress and tends towards agricultural mono-production. Following the regulation of its main rivers, the Nazas and Aguanaval, through dam construction and canalization, the flow of water in the lower basin of the Nazas River has become negligible, which has altered the riverfronts of major cities in the region. Consequently, Torreón, Gómez Palacio, and Lerdo, which are part of the La Laguna Metropolitan Zone (ZML), have expanded into new territories along the riverbanks and adjacent recharge areas. Establishing the boundaries of specific watersheds is crucial for the implementation of targeted rural and urban intervention strategies. This approach enhances understanding of interactions between the natural hydromorphology of a hydrological region, water infrastructure (dams, canals, reservoirs), and the urban and rural landscape. To effectively plan based on watershed boundaries, it is essential to develop hybrid cartographies that integrate urban, architectural, agricultural, and hydrological delineations. These maps provide valuable indicators for watershed-based planning, which facilitates precise hydrological urban restoration strategies tailored to specific basins. This research focuses on developing and presenting such hybrid cartographies, which combine hydrological, rural, and geographic data. This methodology aligns with the overarching objective of mitigating water stress in RH36 and promoting a transition towards more sustainable forms of agriculture. Full article

Gully erosion is one of the most extreme land degradation processes that exhibit spatial and temporal variation depending on topography, soil, climate, and land use and management characteristics. This study investigated the impact of changes in rainfall, land use/land cover (LULC), and land use management (LUM) practices on gully erosion in two midland watersheds (treated Kecha and untreated Laguna) in the Upper Blue Nile basin of Ethiopia by using the LANDPLANER model in combination with intensive field measurements and remote sensing products. We simulated gully erosion under past (in 2005), present (in 2021), and three potential future curve number conditions, each time under four rainfall scenarios (10, 30, 60, and 100 mm) using the dynamic erosion index (e), static topographic (esp), and erosion channel (esp_channel) thresholds. Density plot analyses showed that gullies frequently occur in low-lying gentle slope areas with relatively higher curve number values. The best predictions of gullies identified through true positive rates (TPR) and true negative rates (TNR) were achieved considering the static esp_channel > 1 for Kecha (TPR = 0.667 and TNR = 0.544) and the dynamic e > 0.1 for 60 mm of rainfall in Laguna (TPR = 0.769 and TNR = 0.516). Despite the 10 mm rainfall having negligible erosion-triggering potential in both watersheds, the 60 and 100 mm rainfall scenarios were 4–5 and 10–17 times, respectively, higher than the 30 mm rainfall scenario. While the LULC change in the untreated Laguna watershed increased the impact of rainfall on gully initiation by only 0–2% between 2005 and 2021, the combination of LULC and LUM significantly reduced the impact of rainfall in the treated Kecha watershed by 64–79%. Similarly, the gully initiation area in Kecha was reduced by 28% (from 33% in 2005 to 5% in 2021) due to changes in LULC and LUM practices, whereas Laguna showed little increment by only 1% (from 42% in 2005 to 43% in 2021) due to LULC change. In addition, the future predicted alternative land use planning options showed that gully initiation areas in Laguna could be reduced by 1% with only LULC conversion; 39% when only LUM practices were implemented; and 37% when both were combined. These results indicate that LUM practices outweigh the impact of LULC on gully erosion in the studied paired watersheds. Overall, LANDPLANER successfully simulated the spatio-temporal variation of gully erosion with scenario-based analyses and hence can be used to predict gullies in the study area and other data-scarce regions with similar agro-ecological settings. Full article

Santa Rosa watershed, where the Santa Rosa River and Cabuyao River are located, is growing with increasing urbanization and commercialization in their surroundings. Water quality monitoring is an important tool in understanding the possible impacts of domestic, industrial, and commercial discharges, and agricultural run-off on river systems and their tributaries. With the integration of absorbance and fluorescence measurements, we can further examine the effects of land use and climate change on dissolved organic matter (DOM) sources found in river systems. In this study, these two rivers exhibit poor quality with varying values in each sampling station and period. DOM sources change from terrestrial to endogenous sources within the sampling period. High aromaticity and molecular size were observed in all downstream sampling stations. This is supported by the high values of humic-like substances. Fluorescence index values showed temporal changes from terrestrial to endogenous DOM sources from November 2019 to February 2020. This is also confirmed by the increasing trend in the biological index. The variation in all sampling stations can be attributed to varying land use, hydrological, and climatological changes such as typhoon Tisoy, and Taal Volcano eruption observed during the sampling period. Full article

Lower Laguna Madre (LLM) is designated as an impaired waterway for high concentrations of bacteria and low dissolved oxygen. The main freshwater sources to the LLM flow from the North and Central waterways which are composed of three main waterways: Hidalgo/Willacy Main Drain (HWMD), Raymondville Drain (RVD), and International Boundary & Water Commission North Floodway (IBWCNF) that are not fully characterized. The objective of this study is to perform a watershed characterization to determine the potential pollution sources of each watershed. The watershed characterization was achieved by developing a cyberinfrastructure, and it collects a wide inventory of data to identify which one of the three waterways has a major contribution to the LLM. Cyberinfrastructure development using the Geographic Information System (GIS) database helped to comprehend the major characteristics of each area contributing to the watershed supported by the analysis of the data collected. The watershed characterization process started with delineating the boundaries of each watershed. Then, geospatial and non-geospatial data were added to the cyberinfrastructure from numerous sources including point and nonpoint sources of pollution. Results showed that HWMD and IBWCNF watersheds were found to have a higher contribution to the water impairments to the LLM. HWMD and IBWCNF comprise the potential major sources of water quality impairments such as cultivated crops, urbanized areas, on-site sewage facilities, colonias, and wastewater effluents. Full article

This study investigates different provisioning services in the peri-urban landscapes of Manila conurbation through a case study of two villages in the Jala-Jala municipality of the Laguna de Bay area in the Philippines. Laguna de Bay is an ecologically productive and important watershed for the urban and peri-urban areas of Manila for the provision of food, freshwater, and other materials. However, the lake and its ecosystem are under threat because of rapid urbanization and associated land-use changes. This study is based on a semi-quantitative survey conducted with 90 households in two villages: Special District and Paalaman. It was aimed to capture how provisioning services in the locality are connected with local livelihoods. The results obtained from the study suggest that landscapes in this peri-urban area still has considerable provisioning ecosystem services associated with local biodiversity and that this dependence on provisioning services and their relationship to peri-urban landscapes and biodiversity should be addressed for sustainable landscape management. The results have important implications for the conservation potential of biodiversity on which local livelihoods depend, in urban and peri-urban ecosystems. Full article