Browsing by Author "Perotto-Baldivieso, Humberto L."
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Item Open Access Evolution of green space under rapid urban expansion in Southeast Asian cities(MDPI, 2021-10-30) Muhamad Nor, Amal Najihah; Abdul Aziz, Hasifah; Nawawi, Siti Aisyah; Muhammad Jamil, Rohazaini; Abas, Muhamad Azahar; Hambali, Kamarul Ariffin; Yusoff, Abdul Hafidz; Ibrahim, Norfadhilah; Rafaai, Nur Hairunnisa; Corstanje, Ron; Harris, Jim A.; Grafius, Darren R.; Perotto-Baldivieso, Humberto L.Globally, rapid urban expansion has caused green spaces in urban areas to decline considerably. In this study, the rapid expansion of three Southeast Asia cities were considered, namely, Kuala Lumpur City, Malaysia; Jakarta, Indonesia; and Metro Manila, Philippines. This study evaluates the changes in spatial and temporal patterns of urban areas and green space structure in the three cities over the last two decades. Land use land cover (LULC) maps of the cities (1988/1989, 1999 and 2014) were developed based on 30-m resolution satellite images. The changes in the landscape and spatial structure were analysed using change detection, landscape metrics and statistical analysis. The percentage of green space in the three cities reduced in size from 45% to 20% with the rapid expansion of urban areas over the 25-year period. In Metro Manila and Jakarta, the proportion of green space converted to urban areas was higher in the initial 1989 to 1999 period than over the latter 1999 to 2014 period. Significant changes in green space structure were observed in Jakarta and Metro Manila. Green space gradually fragmented and became less connected and more unevenly distributed. These changes were not seen in Kuala Lumpur City. Overall, the impact of spatial structure of urban areas and population density on green space is higher in Jakarta and Metro Manila when this is compared to Kuala Lumpur. Thus, the results have the potential to clarify the relative contribution of green space structure especially for cities in Southeast Asia where only a few studies in urban areas have taken place.Item Open Access Impact of deforestation on habitat connectivity thresholds for large carnivores in tropical forests(Springer, 2017-07-13) Zemanova, Miriam A.; Perotto-Baldivieso, Humberto L.; Dickins, Emily L.; Gill, Andrew B.; Leonard, John P.; Wester, David B.Introduction Deforestation significantly impacts large carnivores that depend on large tracts of interconnected forest habitat and that are sensitive to human activities. Understanding the relationship between habitat use and spatial distribution of such species across human modified landscapes is critical when planning effective conservation strategies. This study assessed the presence of potential landscape connectivity thresholds resulting from habitat fragmentation associated with different deforestation patterns using a scale-based approach that links species-specific home ranges with the extent of anthropogenic activities. The objectives were (1) to quantify the spatial and temporal distribution of natural vegetation for five common deforestation patterns and (2) to evaluate the connectivity associated with these patterns and the existence of potential thresholds affecting jaguar dispersal. The Bolivian lowlands, located within jaguar conservation units, were analysed with landscape metrics to capture the spatial and temporal changes within deforested areas and to determine potential impact on jaguar connectivity and connectivity thresholds for dispersal. Results Over the period of 1976–2005, the amount of natural vegetation has decreased by more than 40% in all locations with the biggest changes occurring between 1991 and 2000. Landscape spatial structure around jaguar locations showed that jaguars used areas with mean proportion of natural areas = 83.14% (SE = 3.72%), mean patch density = 1.16 patches/100 ha (SE = 0.28 patches/100 ha), mean patch area = 616.95 ha (SE = 172.89 ha) and mean edge density = 705.27 m/ha (SE = 182.19 m/ha).We observed strong fragmentation processes in all study locations, which has resulted in the connectivity of jaguar habitat decreasing to <20% by 2005. A connectivity threshold zone was observed when the proportion of natural vegetation was less than 58.4% (SE = 1.3). Conclusions Assessing fragmentation and connectivity for carnivores within the extent of human-modified landscapes proved to be an effective way to understand the changes caused by deforestation and their potential effects on large carnivore habitats. Our study highlights the importance of scale-based approaches for assessing current conservation challenges to protect large carnivores.Item Open Access Resilience and degradation in a tropical wetland overgrazed by cattle(2014-04-10T00:00:00Z) Santos, Sandra A.; Perotto-Baldivieso, Humberto L.; Young, DylanINTRODUCTION: The Pantanal, one of the largest wetlands in the world, has a great diversity of flora and fauna. The dynamic hydrological regime, combined with heterogeneous to-pography, has resulted in a mosaic of diverse habitat types in terms of species and physical structure. Due to the abundance of forage resources, the Pantanal flood-plains are important for beef cattle production. Cattle prefer grazing near water bodies because these areas have high quality forage as a result of flooding regimes (Santos et al. 2002). Many wetlands go through a wet/dry cycle that is essential to maintain their produc-tivity and function. In drier years, wetland drawdown provides optimal conditions for a diverse range of forage species, and cattle can graze continuously, leading to pasture degradation. It is therefore essential to under-stand the spatial and temporal dynamics of forage production and consumption. In this study we assessed and monitored vegetation at the edge of one of the pond habitats intensively grazed by cattle, in order to evaluate degradation and quantify indicators of resilience (Briske et al. 2006).Item Open Access Spatial and temporal assessment of fragmentation and connectivity analysis for ecotourism activities in a RAMSAR site: Bañados de Isoso (Santa Cruz, Bolivia)(2013-10-02T00:00:00Z) Arancibia-Arce, Luisa R.; Perotto-Baldivieso, Humberto L.; Furlan, Jose R.; Castillo-Garcia, Miguel; Soria, Liliana; Rivero-Guzman, KathiaProtecting biodiversity in RAMSAR sites through conservation activities, like ecotourism, can be very useful to maintain ecological function. There are very few studies in Bolivia that incorporate landscape ecology as a strategic vision for ecotourism in general, and even less that focus on wetlands systems. The aim of this research was to assess the degree of fragmentation and structural connectivity in the landscape in order to understand the anthropogenic processes that have influenced Bañados de Isoso (Santa Cruz, Bolivia) in the last 30 years. To achieve this we used land use change coverage for the Bolivian lowlands (1976-2005) and we quantified changes in vegetation patterns and connectivity through moving windows and spatial sampling based on the scale of a typical ecotourism circuit. The most significant changes occurred after the 1990s with more than 40% natural habitat loss in the northwest and 10-20% in the south. Mean patch areas decreased by more than 75% and patch density increased over 20 times during the same period, indicating a high degree of fragmentation. Connectivity decreased by 5% between 1976 and 2005. Our results show the value of using landscape metrics to assess the impact of human activities within RAMSAR sites and how these activities can be used to encourage strategies, such as ecotourism, to promote landscape conservation.