scholarly journals Deforestation and apparent extinctions of endemic forest beetles in Madagascar

2007 ◽  
Vol 3 (3) ◽  
pp. 344-347 ◽  
Author(s):  
Ilkka Hanski ◽  
Helena Koivulehto ◽  
Alison Cameron ◽  
Pierre Rahagalala
Keyword(s):  
Regional Variation ◽  
Forest Cover ◽  
Dung Beetles ◽  
Insect Species ◽  
Forest Loss ◽  
Focal Species ◽  
Species Area ◽  
Lowland Forests ◽  
Historical Range ◽  
Locality Information

Madagascar has lost about half of its forest cover since 1953 with much regional variation, for instance most of the coastal lowland forests have been cleared. We sampled the endemic forest-dwelling Helictopleurini dung beetles across Madagascar during 2002–2006. Our samples include 29 of the 51 previously known species for which locality information is available. The most significant factor explaining apparent extinctions (species not collected by us) is forest loss within the historical range of the focal species, suggesting that deforestation has already caused the extinction, or effective extinction, of a large number of insect species with small geographical ranges, typical for many endemic taxa in Madagascar. Currently, roughly 10% of the original forest cover remains. Species–area considerations suggest that this will allow roughly half of the species to persist. Our results are consistent with this prediction.

scholarly journals Priority contribution. The rediscovery of Gurney's Pitta Pitta gurneyi in Myanmar and an estimate of its population size based on remaining forest cover

2005 ◽  
Vol 15 (1) ◽  
pp. 3-26 ◽  
Author(s):  
JONATHAN C. EAMES ◽  
HTIN HLA ◽  
PETER LEIMGRUBER ◽  
DANIEL S. KELLY ◽  
SEIN MYO AUNG ◽  
...  
Keyword(s):  
Protected Areas ◽  
Forest Cover ◽  
Secondary Forest ◽  
Forest Edge ◽  
Forest Conversion ◽  
Lowland Forest ◽  
Lowland Forests ◽  
Landsat Satellite ◽  
Global Population ◽  
Historical Range

A preliminary survey for Gurney's Pitta Pitta gurneyi was undertaken at five sites within the species' historical range in the Tanintharyi (Tenasserim) Division of Myanmar from 14 to 24 May 2003. During the surveys, Gurney's Pittas were heard and/or observed at four sites with a maximum of 10–12 pairs recorded at one site. Birds were encountered in logged primary and secondary forest below 100 m on flat ground, sometimes less than 10 m from forest edge. All encounters were within 2 km of the main trans-Tanintharyi highway. Landsat satellite imagery was used to map remaining lowland forests and Gurney's Pitta habitat in the Tanintharyi Division. Our analysis demonstrated that only 4,705 km2 of lowland forest remain with about 3,496 km2 in flat areas with slopes < 10°. On the basis of previously reported population densities, these habitats may support a population of 5,152–8,586 pairs. Much of the remaining habitat is restricted to small and fragmented patches < 1 km2 in area. The five largest patches have a total area of 1,431 km2 and range in size from 137 to 467 km2. This survey demonstrated that Gurney's Pitta still occurs within its historical range in Myanmar, although probably not at any of the historical collecting localities visited. The global population of Gurney's Pitta is at least 100% greater than the latest published estimate. This survey has also shown that the Gurney's Pitta population in southern Tanintharyi Division is under pressure from forest conversion to oil palm. Contrary to the situation in neighbouring Thailand, sufficient forest remains to establish landscape level protected areas covering a broad ecological continuum. Securing populations of Gurney's Pitta within either expanded or entirely new protected areas must be the best chance for the species and the Sundaic flora and fauna of which it is part.

scholarly journals First evidence for an Amazonian insect migration in the butterfly Panacea prola (Lepidoptera: Nymphalidae)

2020 ◽  
Author(s):  
Geoffrey Gallice ◽  
Riccardo Mattea ◽  
Allison Stoiser
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Global Climate ◽  
Insect Species ◽  
Forest Loss ◽  
Environmental Cues ◽  
Mass Movements ◽  
Insect Migration ◽  
Nymphalid Butterfly ◽  
The Tropics

ABSTRACTInsect migrations rival those of vertebrates in terms of numbers of migrating individuals and even biomass, although instances of the former are comparatively poorly documented. This is especially true in the world’s tropics, which harbor the vast majority of Earth’s insect species. Understanding these mass movements is of critical and increasing importance as global climate and land use change accelerate and interact to alter the environmental cues that underlie migration, particularly in the tropics. Here, we provide the first evidence for an insect migration for the nymphalid butterfly Panacea prola in the Amazon, the world’s largest and most biodiverse rainforest that is experiencing a shifting climate and rapid forest loss.

scholarly journals Mexican agricultural frontier communities differ in forest dynamics with consequences for conservation and restoration

2021 ◽  
Author(s):  
Madelon Lohbeck ◽  
Ben DeVries ◽  
Frans Bongers ◽  
Miguel Martinez-Ramos ◽  
Armando Navarrete-Segueda ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Forest Conservation ◽  
Forest Cover ◽  
Secondary Forest ◽  
Forest Loss ◽  
Secondary Forests ◽  
High Quality ◽  
Agricultural Frontier ◽  
Forest Regrowth ◽  
Land Availability

Forest regrowth is key to achieve restoration commitments, but we need to better understand under what circumstances it takes place and how long secondary forests persist. We studied a recently colonized agricultural frontier in southern Mexico. We quantified the spatiotemporal dynamics of forest loss and regrowth and tested how temporal variation in climate, and spatial variation in land availability, land quality and accessibility affect forest disturbance, regrowth and secondary forest persistence. Marqués de Comillas consistently exhibits more forest loss than regrowth, resulting in a net decrease of 30% forest cover (1991-2016). Secondary forest cover remained relatively constant while secondary forest persistence increased, suggesting that farmers are moving away from shifting cultivation. Temporal variation in disturbance and regrowth were explained by the annual variation in the Oceanic El Niño index combined with dry season rainfall and key policy and market interventions.Across communities the availability of high-quality soil overrules the effects of land availability and accessibility, but that at the pixel-level all three factors contributed to explaining forest conservation and restoration. Communities with more high-quality soils were able to spare land for forest conservation, and had less secondary forest that persisted for longer. Old forest and secondary forests were better represented on low-quality lands and on communal land. Both old and secondary forest were less common close to the main road, where secondary forests were also less persistent. Forest conservation and restoration can be explained by a complex interplay of biophysical and social drivers across time, space and scale. We warrant that stimulating private land ownership may cause remaining forest patches to be lost and that conservation initiatives should benefit the whole community. Forest regrowth and secondary forest persistence competes with agricultural production and ensuring farmers can access restoration benefits is key to success.

scholarly journals Multi-taxa ecological responses to habitat loss and fragmentation in western Amazonia as revealed by RAPELD biodiversity surveys

2021 ◽  
Vol 51 (3) ◽  
pp. 234-243
Author(s):  
Gabriel M. MOULATLET ◽  
Emmanuel AMBRIZ ◽  
Jennifer GUEVARA ◽  
Karima G. LÓPEZ ◽  
Marina RODES-BLANCO ◽  
...  
Keyword(s):  
Species Composition ◽  
Habitat Loss ◽  
Forest Cover ◽  
Landscape Fragmentation ◽  
Dung Beetles ◽  
Landscape Configuration ◽  
Edge Density ◽  
Logistic Regression Models ◽  
Habitat Loss And Fragmentation ◽  
Taxonomic Groups

ABSTRACT Habitat loss and fragmentation caused by deforestation are important anthropogenic drivers of changes in biodiversity in the Amazon rainforest, and has reached its highest rate in recent decades. However, the magnitude and direction of the effects on species composition and distribution have yet to be fully understood. We evaluated the responses of four taxonomic groups − birds, amphibians, orchid bees, and dung beetles - to habitat loss and fragmentation at both species and assemblage level in the northern Ecuadorian Amazon. We sampled fifteen 250-m long plots in terra-firme forest remnants. We calculated one landscape fragmentation index (fragindex), which considers the proportion of continuous forest cover, edge density and isolation in the landscape, and nine landscape configuration metrics. Logistic regression models and multivariate regression trees were used to analyze species and assemblage responses. Our results revealed that over 80% of birds, amphibians or orchid-bee species, and 60% of dung beetles were negatively affected by habitat loss and fragmentation. Species composition of all taxonomic groups was significantly affected by differences in forest cover and connectivity. Less than 5% of all species were restricted to landscapes with fragindex values higher than 40%. Landscape metrics related to the shape and area of forest patches determined the magnitude and direction of the effect on species responses. Therefore, changes in the landscape configuration of Ecuadorian Amazonia should be minimized to diminish the effects of habitat loss and fragmentation on species occurrence and assemblage composition.

scholarly journals Contributing Factors to Forest Loss in Conterminous U.S. for the 1990s and 2000s

2021 ◽  
Vol 02 (04) ◽  
pp. 1-1
Author(s):  
Giorgos Mountrakis ◽  
◽  
Sheng Yang ◽  
Keyword(s):  
Forest Cover ◽  
Explanatory Power ◽  
National Level ◽  
Influential Factor ◽  
Local Context ◽  
Forest Loss ◽  
The South ◽  
Contributing Factors ◽  
Spatial Error ◽  
Forested Areas

While numerous studies have considered forest loss factors at local scales, there is a gap of comparative quantitative regional modeling at the U.S. national level. Here, we investigated statistical relationships between gross forest cover loss (GFCL) and numerous socioeconomic, biophysical and ownership variables between two decades, the 1990s and the 2000s. A spatial error model was employed to compensate for spatial autocorrelation effects. Models from the 2000s had stronger explanatory power than the 1990s models, especially in the Northeast and the South (R<sup>2</sup> of 0.89 and 0.87 respectively). The amount of forested areas in low slopes was a highly influential factor for high GFCL, followed by urban area cover and mill density. On the other hand, agricultural cover was negatively correlated with GFCL acting as a stabilizing factor in the South and Midwest regions. Our study offers an important insight in regional drivers of GFCL, drivers that should be further examined in the local context to gather better understanding of their contributions.

Spatial Model Approach for Deforestation

2013 ◽  
pp. 1901-1912
Author(s):  
Lilik B. Prasetyo ◽  
Chandra Irawadi Wijaya ◽  
Yudi Setiawan
Keyword(s):  
Population Density ◽  
Rural Areas ◽  
Forest Cover ◽  
Positive Impact ◽  
Forest Loss ◽  
Road Density ◽  
Policy Makers ◽  
Explanatory Variables ◽  
The Government ◽  
Negative Impacts

Java is very densely populated since it is inhabited by more than 60% of the total population of Indonesia. Based on data from the Ministry of Forestry, forest loss between 2000-2005 in Java was about 800,000 hectares. Regardless of the debate on whether the different methodologies of forest inventory applied in 2005 have resulted in an underestimation of the figure of forest loss or not, the decrease of forest cover in Java is obvious and needs immediate response. Spatial modeling of the deforestation will assist the policy makers in understanding this process and in taking it into consideration, when decisions are made on the issue. Moreover, the results can be used as data input to solve environmental problems resulting from deforestation. The authors of this chapter modeled the deforestation in Java by using logistic regression. Percentage of deforested area was considered as the response variable, whilst biophysical and socioeconomic factors, that explain the current spatial pattern in deforestation, were assigned as explanatory variables. Furthermore, the authors predicted the future deforestation process, and then, for the case of Java, it was validated with the actual deforestation derived from MODIS satellite imageries from 2000 to 2008. Results of the study showed that the impacts of population density, road density, and slope are significant. Population density and road density have negative impacts on deforestation, while slope has positive impact. Deforestation on Java Island tends to occur in remote areas with limited access, low density population and relatively steep slopes. Implication of the model is that the government should pay more attention to remote rural areas and develop good access to accelerate and create alternative non agricultural jobs in order to reduce pressure on the forest.

Spatial Model Approach for Deforestation

2011 ◽  
pp. 376-387 ◽  
Author(s):  
Lilik B. Prasetyo ◽  
Chandra Irawadi Wijaya ◽  
Yudi Setiawan
Keyword(s):  
Population Density ◽  
Rural Areas ◽  
Forest Cover ◽  
Positive Impact ◽  
Forest Loss ◽  
Road Density ◽  
Policy Makers ◽  
Explanatory Variables ◽  
The Government ◽  
Negative Impacts

Java is very densely populated since it is inhabited by more than 60% of the total population of Indonesia. Based on data from the Ministry of Forestry, forest loss between 2000-2005 in Java was about 800,000 hectares. Regardless of the debate on whether the different methodologies of forest inventory applied in 2005 have resulted in an underestimation of the figure of forest loss or not, the decrease of forest cover in Java is obvious and needs immediate response. Spatial modeling of the deforestation will assist the policy makers in understanding this process and in taking it into consideration, when decisions are made on the issue. Moreover, the results can be used as data input to solve environmental problems resulting from deforestation. The authors of this chapter modeled the deforestation in Java by using logistic regression. Percentage of deforested area was considered as the response variable, whilst biophysical and socioeconomic factors, that explain the current spatial pattern in deforestation, were assigned as explanatory variables. Furthermore, the authors predicted the future deforestation process, and then, for the case of Java, it was validated with the actual deforestation derived from MODIS satellite imageries from 2000 to 2008. Results of the study showed that the impacts of population density, road density, and slope are significant. Population density and road density have negative impacts on deforestation, while slope has positive impact. Deforestation on Java Island tends to occur in remote areas with limited access, low density population and relatively steep slopes. Implication of the model is that the government should pay more attention to remote rural areas and develop good access to accelerate and create alternative non agricultural jobs in order to reduce pressure on the forest.

scholarly journals Contrasting Trends of Forest Coverage between the Inland and Coastal Urban Groups of China over the Past Decades

2019 ◽  
Vol 11 (16) ◽  
pp. 4451 ◽  
Author(s):  
Qingsong Zhu ◽  
Jiaxin Jin ◽  
Pengxiang Wang ◽  
Yingying Ji ◽  
Yuanyuan Xiao ◽  
...  
Keyword(s):  
Forest Cover ◽  
Anthropogenic Factors ◽  
Forest Loss ◽  
Fast Process ◽  
Urban Agglomerations ◽  
The Past ◽  
Forest Coverage ◽  
Forest Cover Changes ◽  
Process Of Urbanization ◽  
Natural And Anthropogenic Factors

China is building forest urban groups through reforestation and afforestation. However, the fast process of urbanization inevitably conflicts with multiple vegetated areas around cities. Hence, it is critical to evaluate the changes in regional vegetation cover and its spatial pattern due to complex natural and anthropogenic factors. Nevertheless, systematic studies to quantify and compare the development of forest urban agglomerations were rarely reported. Based on a remote sensing landcover dataset from 1992 to 2015, this study investigated forest cover changes and the impacts on landscape pattern in several urban groups, and tried to explore their differences between the inland and coastal regions of China. The results showed that over the past 24 years, the forest coverage in the coastal urban agglomerations declined (103 km2/year) while it increased (26 km2/year) in the inland urban agglomerations. There was a certain conflict between forest and cropland for the coastal urban agglomerations where the forest area converted to cropland accounted for 61.9% of the total forest loss. The increase in forests coverage in inland urban agglomerations mainly came from grassland which nearly accounted for 66.47% of the total increase. The landscape diversity has also changed in areas where forests have changed significantly (e.g., Shanghai, Changzhi, and Jincheng).

Causes and history of forest loss in Cambodia

2019 ◽  
Vol 21 (3) ◽  
pp. 372-384 ◽  
Author(s):  
R. TSUJINO ◽  
T. KAJISA ◽  
T. YUMOTO
Keyword(s):  
Forest Cover ◽  
Arable Land ◽  
Growth Period ◽  
Rapid Expansion ◽  
Small Scale ◽  
Forest Loss ◽  
Rapid Economic Growth ◽  
History Of ◽  
Post War ◽  
The 1960S

To reconstruct the history of forest loss in Cambodia, the literature and national/provincial statistics of landuse patterns and the socio-economic situation were investigated. Forest cover in the 1960s was 73.3 % (13.3 Mha). However, this drastically decreased to 47.3% (8.6 Mha) in 2016. In the 1960s, the forest was less-disturbed. From 1970 to 1993, the forest was lost gradually owing to the political instability caused by the Cambodian Civil War. In the post-war reconstruction period from 1993 to around 2002, the need for reconstruction, international demand for timber, and forest logging concessions led to a significant increase in timber production. In the rapid economic growth period from 2002 until present, while several political actions were taken to combat rapid deforestation, economic land concessions, which promoted agroindustrial plantations, as well as small-scale agriculture has been leading to the rapid expansion of arable land and deforestation since 2009.

scholarly journals Białowieża Forest—A Relic of the High Naturalness of European Forests

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 849 ◽  
Author(s):  
Bogdan Jaroszewicz ◽  
Olga Cholewińska ◽  
Jerzy M. Gutowski ◽  
Tomasz Samojlik ◽  
Marcelina Zimny ◽  
...  
Keyword(s):  
Forest Cover ◽  
Historical Data ◽  
Open Door ◽  
Białowieża Forest ◽  
Continuous Forest ◽  
Lowland Forests ◽  
The Stability ◽  
Natural Dynamics ◽  
And Function ◽  
High Degree

In Europe only some small isolated patches of forests with a high degree of naturalness still exist. These are forests, whose structure, composition and function has been shaped by natural dynamics without substantial anthropogenic influence over the long period. In this respect, Białowieża Forest is a unique location in Europe, with continuous forest cover for close to 12,000 years. The palynological, archaeological and historical data document only a weak anthropogenic fingerprint compared to other European lowland forests in Holocene history. Due to long-lasting protection, a large portion of the forest is still composed of stands originating from the pre-silvicultural period. Moreover, the stands of Białowieża Forest converted by silvicultural activities during the 20th century have the potential to recover owing to patches of stands with high naturalness, scattered throughout the forest. As conflict over management of the forest has recurred regularly for close to century, there is a need to summarize our knowledge on the forest history and natural assets, to help making scientifically informed decisions over its future. Expansion of a non-intervention approach to the Polish part of the forest is suggested to increase the stability of the entire ecosystem and enhance the chances for its successful adaptation to changing environmental conditions. This will increase the importance of Białowieża Forest as an open-door laboratory for biology, ecology, and forestry.

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