scholarly journals Nature representativeness in South American protected areas: Country contrasts and conservation priorities

2018 ◽  
Author(s):  
Germán Baldi ◽  
Santiago A. Schauman ◽  
Marcos Texeira ◽  
Sofía Marinaro ◽  
Osvaldo A. Martin ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Random Forest ◽  
Population Density ◽  
Protected Areas ◽  
Two Dimensions ◽  
Conservation Priorities ◽  
South American ◽  
Natural Conditions ◽  
Physical Approach ◽  
Natural Diversity

ABSTRACTBackgroundSouth America faces strong environmental transformations due to agriculture and infrastructure expansion and due to demographic growth, demanding immediate action to preserve natural assets by means of the deployment of protected areas. Currently, 7.1% of the (sub)continent is under strict conservation categories (I to IV, IUCN), but the spatial distribution of these 1.3 x 106 km2 is poorly understood. We evaluate protected area representativeness, map conservation priorities and assess demographic, productive or geopolitical causes of the existing protection spatial patterns using a random forest method.MethodsWe characterized representativeness by two dimensions: the extent and the equality of protection. The first refers to the fraction of a territory under protection, while the second refers to the spatial distribution of this protection along natural conditions. We characterized natural conditions by 113 biogeographical units (specifically, ecoregions) and a series of limited and significant climatic, topographic and edaphic traits. We analyzed representativeness every ten years since 1960 at national and continental levels. In the physical approach, histograms allowed us to map the degree of conservation priorities. Finally, we ranked the importance of different productive or geopolitical variables driving the observed distributions with a random forest technique.ResultsRepresentativeness was variable across countries in spite of its priority in conservation agendas. Brazil, Peru and Argentina underrepresented a significant fraction of their natural diversity, while Bolivia and Venezuela protected their natural diversity equitably under extensive conservation networks. As protected networks increased their extent, so did their equality across countries and within them through time. Mapping revealed as top continental priorities southern temperate, subhumid and fertile lowland environments, and other country- specific needs (e.g., hot, humid plains of Venezuela). Protection extent was generally driven by a low population density and isolation, while other variables –like distance to frontiers, were relevant only locally (e.g., in Argentina).DiscussionOur description of the spatial distribution can help societies and governments to improve the allocation of conservation efforts, being top continental priorities the southern temperate, subhumid and fertile lowland environments. We identify the main limitations that future conservation efforts will face, as protection was generally driven by the opportunities provided by low population density and isolation. From a methodological perspective, the complementary physical approach reveals new properties of protection and provides tools to explore nature representativeness at different spatial, temporal and conceptual levels, complementing the traditional ones based on biodiversity or biogeographical attributes.

scholarly journals Nature representation in South American protected areas: country contrasts and conservation priorities

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7155 ◽  
Author(s):  
Germán Baldi ◽  
Santiago Schauman ◽  
Marcos Texeira ◽  
Sofía Marinaro ◽  
Osvaldo A. Martin ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Population Density ◽  
Protected Areas ◽  
Conservation Priorities ◽  
South American ◽  
Natural Conditions ◽  
Environmental Pressures ◽  
Physical Approach ◽  
Demographic Growth ◽  
Country Specific

Background South America faces strong environmental pressures as a result of agriculture and infrastructure expansion and also of demographic growth, demanding immediate action to preserve natural assets by establishing protected areas. Currently, 7.1% of the (sub)continent is under strict conservation categories (I to IV, IUCN), but the spatial distribution of these 1.3 × 106 km2 is poorly understood. We evaluated the representation of nature within the networks of protected areas, map conservation priorities and assess demographic, economic or geopolitical causes of existing protection patterns. Methods We characterized nature representation by looking at two components: the extent and the equality of protection. The first refers to the fraction of territory under protection, while the second refers to the homogeneity in the distribution along natural conditions of this protected fraction. We characterized natural conditions by either 113 biogeographical units (specifically, ecoregions) or a series of limited and significant climatic, topographic and edaphic traits. We analyzed representation every ten years since 1960 at national and continental levels. In the physical approach, histograms allowed us to map the degree of conservation priorities. Finally, we ranked the importance of different economic or geopolitical variables driving the observed distributions with a random forest technique. Results Nature representation varied across countries in spite of its priority in conservation agendas. In Brazil, Peru and Argentina there are still natural conditions with no formal protection, while in Bolivia and Venezuela, protected areas incorporate the natural diversity in a more balanced manner. As protected networks have increased their extent, so did their equality across and within countries over time. Our maps revealed as top continental priorities the southern temperate, subhumid and fertile lowland environments, and other country-specific areas. Protection extent was generally driven by a low population density and isolation, while other variables like distance to frontiers, were relevant only locally (e.g., in Argentina). Discussion Our description of the spatial distribution of protected areas can help societies and governments to improve the allocation of conservation efforts. We identified the main limitations that future conservation efforts will face, as protection was generally driven by the opportunities provided by low population density and isolation. From a methodological perspective, the physical approach reveals new properties of protection and provides tools to explore nature representation at different spatial, temporal and conceptual levels, complementing the traditional ones based on biodiversity or biogeographical attributes.

scholarly journals Spatially Explicit Mapping of Historical Population Density with Random Forest Regression: A Case Study of Gansu Province, China, in 1820 and 2000

2020 ◽  
Vol 12 (3) ◽  
pp. 1231 ◽  
Author(s):  
Fahao Wang ◽  
Weidong Lu ◽  
Jingyun Zheng ◽  
Shicheng Li ◽  
Xuezhen Zhang
Keyword(s):  
Spatial Distribution ◽  
Random Forest ◽  
Population Density ◽  
Census Data ◽  
Gansu Province ◽  
Spatially Explicit ◽  
Random Forest Regression ◽  
Independent Variables ◽  
Population Weighting

This study established a random forest regression model (RFRM) using terrain factors, climatic and river factors, distances to the capitals of provinces, prefectures (Fu, in Chinese Pinyin), and counties as independent variables to predict the population density. Then, using the RFRM, we explicitly reconstructed the spatial distribution of the population density of Gansu Province, China, in 1820 and 2000, at a resolution of 10 by 10 km. By comparing the explicit reconstruction with census data at the township level from 2000, we found that the RFRM-based approach mostly reproduced the spatial variability in the population density, with a determination coefficient (R2) of 0.82, a positive reduction of error (RE, 0.72) and a coefficient of efficiency (CE) of 0.65. The RFRM-based reconstructions show that the population of Gansu Province in 1820 was mostly distributed in the Lanzhou, Gongchang, Pingliang, Qinzhou, Qingyang, and Ningxia prefecture. The macro-spatial pattern of the population density in 2000 kept approximately similar with that in 1820. However, fine differences could be found. The 79.92% of the population growth of Gansu Province from 1820 to 2000 occurred in areas lower than 2500 m. As a result, the population weighting in the areas above 2500 m was ~9% in 1820 while it was greater than 14% in 2000. Moreover, in comparison to 1820, the population density intensified in Lanzhou, Xining, Yinchuan, Baiyin, Linxia, and Tianshui, while it weakened in Gongchang, Qingyang, Ganzhou, and Suzhou.

La política migratoria de Ecuador hacia Colombia Entre la integración y la “contención“

2011 ◽  
Vol 1 (2) ◽  
pp. 45-77 ◽  
Author(s):  
Marcela Ceballos Medina
Keyword(s):  
Immigration Policy ◽  
Forced Migration ◽  
Two Dimensions ◽  
Politique Publique ◽  
Political Agenda ◽  
The Political ◽  
South American ◽  
Internal Armed Conflict ◽  
Normative Framework ◽  
South American Region

This article examines Ecuadoran policy toward the forced migration of Colombians to Ecuador. It identifies the main changes in Ecuadoran immigration policy, including asylum, for the period 1996-2008. To do this, the author examines two dimensions of immigration policy: the normative framework and political practices (implementation of the normative framework). The article tries to answer the following questions: What are the main changes in Ecuadoran immigration policy toward Colombian forced migration? How can we explain those changes? The author suggests that the policy oscillates between regional or binational integration and border contention. The variables that explain those changes are: (1) the magnitude of Colombian migration; (2) the transnational dynamics of the internal armed conflict along the Colombia-Ecuador border and the political context in Ecuador; and (3) the international relations of Colombia and Ecuador and the political agenda of the South American region.Spanish El propósito del artículo es examinar la respuesta del Estado ecuatoriano a las migraciones forzadas de colombianos hacia ese país, identificando los principales cambios en la política de inmigración (incluida la política de asilo y refugio) de Ecuador durante el periodo 1996- 2008. Para ello, se observan dos dimensiones de la política migratoria ecuatoriana: 1) el marco normativo y 2) las prácticas políticas para la implementación de las normas. La autora se propone responder a las preguntas ¿Cuáles son los principales cambios en la política migratoria del Estado ecuatoriano hacia las migraciones colombianas? ¿Cómo se explican esos cambios? Concluye que la política migratoria de Ecuador hacia las migraciones colombianas oscila entre una posición integracionista y abierta a la inmigración y una política de cierre de fronteras y contención del conflicto armado dentro del territorio colombiano. Las variables que explican dichos cambios son: 1) el creciente flujo de migrantes colombianos hacia Ecuador, 2) las dinámicas transnacionales del conflicto armado colombiano en la frontera y el contexto político al interior del Ecuador, y 3) las relaciones político-diplomáticas entre los dos países y la agenda política en la región suramericana.French Cet article examine la politique de l'Équateur concernant l'immigration forcée de Colombiens vers ce pays. Il identifie les changements principaux effectués dans la politique d'immigration équatorienne (en incluant la politique publique d'asile) pour la période 1996-2008. Dans ce but, l'auteur examine deux dimensions de la politique publique d'immigration : 1) le cadre normatif, et 2) les pratiques politiques (la mise en œuvre du cadre normatif). L'auteur souhaite répondre aux questions suivantes : quels sont les changements principaux dans la politique d'immigration équatorienne concernant les migrations colombiennes forcées ? Comment pouvons-nous expliquer ces changements ? L'hypothèse est que la politique d'immigration de l'Équateur oscille entre l'intégration régionale ou binationale et le contrôle des frontières. Les variables perme ant d'expliquer ces changements sont : 1) l'ampleur des migrations colombiennes vers l'Équateur ; 2) les dynamiques transnationales du conflit armé interne au niveau de la frontière colombo-équatorienne et le contexte politique en Équateur ; et 3) les relations internationales entre la Colombie et l'Équateur ainsi que l'agenda politique de la région sud-américaine.

scholarly journals Regionally extinct species rediscovered: the bush dog Speothos venaticus in Minas Gerais, south-eastern Brazil

Oryx ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Guilherme Braga Ferreira ◽  
Marcelo Juliano Rabelo Oliveira ◽  
Rogério Cunha de Paula ◽  
Flávio Henrique Guimarães Rodrigues ◽  
Érica Daniele Cunha Carmo
Keyword(s):  
Protected Areas ◽  
Minas Gerais ◽  
The State ◽  
South American ◽  
North West ◽  
South Eastern ◽  
The North ◽  
Eastern Brazil ◽  
Bush Dog ◽  
Speothos Venaticus

AbstractThe bush dog Speothos venaticus, a rare Near Threatened South American canid that lives in packs, was thought to be extinct in Minas Gerais state, south-eastern Brazil, until recently. Here, we report four recent records of the species in Minas Gerais, the first in the state since the description of the species in 1842. All records are from the Cerrado ecosystem in the north and north-west of the state; two are from animals found dead, one from footprints and another from a camera trap. Three of the records were inside or close (< 10 km) to strict protected areas, in a region recognized as the Protected Areas Mosaic Sertão Veredas–Peruaçu, where we expect any new records of the bush dog to be found. We discuss the low probability of detecting the bush dog and the main regional threats to the species, and emphasize the need to protect large and interconnected natural areas and keep them free of domestic dogs to avoid the extinction of the bush dog in Minas Gerais.

scholarly journals Spatial distribution and survival rate of waterfrog tadpoles in relation to biotic and abiotic factors: a field experiment

2001 ◽  
Vol 22 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Sylvie Thurnheer ◽  
Heinz-Ulrich Reyer
Keyword(s):  
Spatial Distribution ◽  
Community Dynamics ◽  
Abiotic Factors ◽  
Rana Esculenta ◽  
Natural Conditions ◽  
Major Purpose ◽  
Biotic And Abiotic Factors ◽  
Lab Experiments ◽  
Shallow Zone ◽  
Population And Community Dynamics

AbstractPredictions about population and community dynamics are usually based on lab experiments. Because the results are difficult to transfer to natural conditions, the major purpose of this study was to test the effects of biotic and abiotic factors on tadpole populations in a natural environment. We stocked six ponds, created the previous year, with known numbers of Rana esculenta and R. lessonae tadpoles and followed their development over several months. When compared among ponds, tadpole density correlated positively with the nitrate:phosphate ratio. This suggests that water chemistry may have affected survival, either directly or indirectly via productivity. Within ponds, both species showed a clear preference for the shallow zone. This behavior probably reflects a preference for warm water close to the surface, rather than avoidance of predators, because relative densities of odonates also increased from deep to shallow zones. This study is one of few that not only considers the distribution of the anuran tadpoles but the distribution of their predators as well.

Spatial distribution and fluctuating populations of predatory mites (Mesostigmata: Phytoseiidae), phytophagous mites (Acari: Eriophyidae, Tetranychidae) and their relationships with wild chili pepper phenological stages in two Natural Protected Areas of Mexico

2022 ◽  
Author(s):  
José Irving Monjarás-barrera ◽  
Mario Rocandio-rodríguez ◽  
Cristina Domínguez-castro ◽  
Francisco Reyes-zepeda ◽  
Sandra Grisell Mora-ravelo ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Protected Areas ◽  
Distribution Pattern ◽  
Mite Species ◽  
Chili Pepper ◽  
Phenological Stages ◽  
Natural Protected Areas ◽  
Settlement Development ◽  
Phytophagous Mites ◽  
Dispersion Patterns

Ecological interactions between mites (predatory and phytophagous) and wild plants growing in undisturbed environments play a crucial role to understand their natural settlement, development and dispersion patterns. Pequin chili pepper, Capsicum annuum L. var. glabriusculum, is a low-cost natural resource for local communities living inside Natural Protected Areas (ANP) of Tamaulipas State in Mexico. The aims of this research work were: 1) determine the spatial distribution pattern of predatory and phytophagous mites, 2) determine the spatiotemporal association between predatory and phytophagous mites, and 3) determine the association among different mite species and some phenological stages of Pequin chili pepper. The most abundant phytophagous mites were Tetranychus merganser and Aculops lycpoersici, and the predatory species were Amblyseius similoides, Euseius mesembrinus and Metaseiulus (Metaseiulus) negundinis. Most mite species showed an aggregated distribution pattern according to the plant phenological stages. However, the distribution of mite species throughout time showed different types of aggregation. On the other hand, we found positive associations among A. lycopersici and T. merganser phytophagous mites with A. similoides, E. mesembrinus and M. (M.) negundinis predators mites. The association between plants and mite species were influenced by the phenological stages of Pequin chili pepper. This is an indication of the complexity among trophic-chain interactions that depend largely on the available resources and competition. These two factors serve as foundations for settlement, development and dispersion patterns of certain species.

scholarly journals Conservation priorities for terrestrial mammals in Dobrogea Region, Romania

ZooKeys ◽  
2018 ◽  
Vol 792 ◽  
pp. 133-158 ◽  
Author(s):  
Iulia V. Miu ◽  
Chisamera Gabriel B. ◽  
Viorel D. Popescu ◽  
Ruben Iosif ◽  
Andreea Nita ◽  
...  
Keyword(s):  
Protected Areas ◽  
Environmental Changes ◽  
Natura 2000 ◽  
Habitats Directive ◽  
Conservation Priorities ◽  
Terrestrial Mammals ◽  
Core Areas ◽  
Mammal Distribution ◽  
Intensive Sampling ◽  
Mammal Diversity

Based on species occurrence records of museum collections, published literature, and unpublished records shared by mammalian experts, we compiled a distribution database for 59 terrestrial mammals populating the extensively protected Dobrogea Region of Romania. The spatial patterns of mammal distribution and diversity was evaluated and systematic conservation planning applied to identify priority areas for their conservation. The spatial analyses revealed that intensive sampling was not directly correlated to mammal diversity but rather to accessibility for inventory. The spatial prioritisation analysis indicated a relatively aggregated pattern of areas with a high or low conservation value with virtually no connecting corridors between them. The significant overlap between Natura 2000 sites and national protected areas induced an over-optimistic vision of the effectiveness and representativeness of existing Natura 2000 network for species found in Annexes II and IV of the Habitats Directive. These results represent a key step in identifying core areas for the protection of mammal diversity and dispersal corridors for improved connectivity, and to guide future conservation efforts in increasing the effectiveness of the existing protected areas in the context of environmental changes.

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