MODIS time series as a tool for monitoring fires and their effects on savanna bird diversity

2012 ◽  
Vol 21 (6) ◽  
pp. 680 ◽  
Author(s):  
Noam Levin ◽  
Sarah Legge ◽  
Bronwyn Price ◽  
Michiala Bowen ◽  
Emily Litvack ◽  
...  

In this study, we aimed to explore the effect of fires on bird diversity in Australia’s tropical savannas. Bird surveys were conducted at 69 sites between 2005 and 2007 to estimate bird species richness and abundance within the Mornington Sanctuary, the Kimberley, north-west Australia. We used MODIS (Moderate Resolution Imaging Spectroradiometer) and Landsat satellite imagery to map fire scars and to quantify vegetation cover parameters, and QuickBird imagery to map the percentage tree cover. Bird species richness and abundance were higher in areas exhibiting minimum seasonal and interannual changes, e.g. in riparian areas, near water and where tree cover was high. We found a significant negative effect of fire on bird diversity following the extensive late dry-season fires of 2006. These findings support the view that intense and large fires are threatening biodiversity and reinforce the importance of reducing the occurrence of late dry-season fires, which are the most severe and extensive. MODIS satellite imagery was found to provide a cost-effective approach to monitoring savanna landscapes, assessing the state of vegetation and monitoring fire dynamics.

2012 ◽  
Vol 26 (6) ◽  
pp. 1100-1111 ◽  
Author(s):  
Alexandre Camargo Martensen ◽  
Milton Cezar Ribeiro ◽  
Cristina Banks-Leite ◽  
Paulo Inácio Prado ◽  
Jean Paul Metzger

Ostrich ◽  
2013 ◽  
Vol 84 (1) ◽  
pp. 33-39 ◽  
Author(s):  
P Kariuki Ndang'ang'a ◽  
John BM Njoroge ◽  
Kamau Ngamau ◽  
Wariara Kariuki ◽  
Philip W Atkinson ◽  
...  

2018 ◽  
Vol 10 (7) ◽  
pp. 1136 ◽  
Author(s):  
Sébastien Bonthoux ◽  
Solenne Lefèvre ◽  
Pierre-Alexis Herrault ◽  
David Sheeren

Continuous-based predictors of habitat characteristics derived from satellite imagery are increasingly used in species distribution models (SDM). This is especially the case of Normalized Difference Vegetation Index (NDVI) which provides estimates of vegetation productivity and heterogeneity. However, when NDVI predictors are incorporated into SDM, synchrony between biological observations and image acquisition must be questionned. Due to seasonal variations of NDVI during the year, landscape patterns of habitats are revealed differently from one date to another leading to variations in models’ performance. In this paper, we investigated the influence of acquisition time period of NDVI to explain and predict bird community patterns over France. We examined if the NDVI acquisition period that best fit the bird data depends on the dominant land cover context. We also compared models based on single time period of NDVI with one model built from the Dynamic Habitat Index (DHI) components which summarize variations in vegetation phenology throughout the year from the fraction of radiation absorbed by the canopy (fPAR). Bird species richness was calculated as response variable for 759 plots of 4 km2 from the French Breeding Bird Survey. Bird specialists and generalists to habitat were considered. NDVI and DHI predictors were both derived from MODIS products. For NDVI, five time periods in 2010 were compared, from late winter to begin of autumn. A climate predictor was also used and Generalized Additive Models were fitted to explain and predict bird species richness. Results showed that NDVI-based proxies of dominant habitat identity and spatial heterogeneity explain more bird community patterns than DHI-based proxies of annual productivity and seasonnality. We also found that models’ performance was both time and context-dependent, varying according to the bird groups. In general, best time period of NDVI did not match with the acquisition period of bird data because in case of synchrony, differences in habitats are less pronounced. These findings suggest that the most powerful approach to estimate bird community patterns is the simplest one. It only requires NDVI predictors from a single appropriate time period, in addition to climate, which makes the approach very operational.


2017 ◽  
Vol 65 (4) ◽  
pp. 1625
Author(s):  
Jose Alejandro Vergara Paternina ◽  
Jesús Ballesteros Correa ◽  
Carlos González Charrasquiel ◽  
Juan C. Linares Arias

In Colombia the tropical dry forest is one of the most threatened and least known ecosystems; these have been impacted by different transformation processes and habitat fragmentation, which have affected bird conditions and survival. This research evaluated the influence of landscape elements (forest and pastures with different tree covers) on bird diversity in the tropical dry forest of Córdoba, Colombia. The study was developed within an extensive livestock landscape to characterize the avifauna in four habitat types formed by fragments of secondary forests with different tree cover: secondary forest, pastures with high tree cover, pastures with low tree cover and only pastures. The influence of tree cover on bird diversity was evaluated with monthly samplings in 200 m long transects (per habitat), with two observation intervals (6:00 - 9:00 and 15:00-18:00), from September 2011 to May 2012. A total of 6 667 individuals belonging to 180 species and 48 families of birds were registered. The most abundant species were Columbina talpacoti (5.37 %), Brotogeris jugularis (5.14 %), Tyrannus melancholicus (4.81 %) and Bubulcus ibis (4.80 %). The most abundant family was Tyrannidae (16.4 %), followed by Psitacidae (9.0 %) and Columbidae (8.2 %). The family with the highest number of species was Tyrannidae with 28 species, followed by Accipitridae and Icteridae with 10 species each. The greatest species richness was present in the secondary forest habitat, followed by the pastures with high tree cover, and pastures with low cover. The lowest abundance and species richness was found in pastures without tree cover with significant differences between the habitats (Fisher, p <0.05). According to the Shannon index, the diversity of birds was higher in the secondary forests. In contrast, the lowest diversity was found in pastures without tree cover. The greatest species richness occurred in the months of October and November. In the rest of the sampling period, the number of recorded species and individuals showed some stability. The importance of trees presence in extensive livestock areas was evidenced because they help to contain an important diversity of bird species, and they also generate connectivity among fragments of secondary forests in the cattle landscape.


2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.


2018 ◽  
Author(s):  
Jin-Yong Kim ◽  
Sanghun Lee ◽  
Man-Seok Shin ◽  
Chang-Hoon Lee ◽  
Changwan Seo ◽  
...  

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these remain controversial. This study investigated the causes of altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in Jirisan National Park, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1400 m above mean sea level in the breeding season. A total of 2771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 16 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity, and that density was positively correlated with vertical, but not horizontal, habitat heterogeneity, and negatively correlated with migrant rate. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. And neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.


2009 ◽  
Vol 36 (7) ◽  
pp. 581 ◽  
Author(s):  
Amelia J. Koch ◽  
Sarah A. Munks ◽  
Chris Spencer

Context. The retention of mature eucalypts in plantation areas is expected to have biodiversity benefits, especially for animals with specific requirements such as hollow-using species. Aims. The aim of the current study was to examine the degree to which retained trees embedded in young (≤3 years old) eucalypt plantation provide habitat for birds, whether as a perching/foraging resource for all bird species or as a potential shelter/breeding site for hollow-using species. Methods. We examined bird use of remnant trees in young eucalypt plantations at five sites in northern Tasmania. Four 20-min surveys were done on 214 trees (101 of these had visible hollows) over two breeding seasons (2007 and 2008). Bird activity at a hollow was recorded during all four surveys, whereas the number of bird species observed in a tree was only recorded during two surveys in the first breeding season. The relationship between both species richness and hollow use with site and tree variables was explored using hierarchical partitioning. Key results. Bird species richness at a tree was most strongly related to which of the five properties the tree was located on. This may be due to differences in soil fertility and/or the amount of forested area within and around the property. Birds were observed investigating 50 hollows on 36 trees. More than one hollow was used in 10 trees and hollow use was most strongly related to hollow abundance in a tree. High re-use of particular trees (n = 15) and hollows (n = 16) indicates that retained trees vary in the type and quality of habitat they provide for hollow-using birds. The most common hollow users observed were the common starling (Sturnus vulgaris) and the striated pardalote (Pardalotus striatus). Conclusions and implications. Retaining trees in plantation areas, particularly trees with special features such as hollows, should be encouraged to provide habitat for birds and help contribute to the maintenance of bird diversity in an area.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xueru Yang ◽  
Xinwei Tan ◽  
Chuanwu Chen ◽  
Yanping Wang

Abstract Background Habitat loss, fragmentation and decrease of habitat quality caused by urbanization have led to a dramatic decline in biodiversity worldwide. For highly urbanized areas, parks have become “islands” or habitat fragments for wildlife. As an important indicator group of urban ecosystem health, the response of birds to urbanization has attracted the global attention of ecologists. Understanding the key factors affecting bird diversity in urbanized environment is crucial to the protection of biodiversity in urban ecosystems. Methods We used the line-transect method to survey birds in 37 urban parks in Nanjing, China. We also measured a number of park characteristics (area, isolation, shape index, environmental noise, distance to city center, and habitat diversity) that are commonly assumed to influence bird diversity. We then used the information-theoretic multi-model inference approach to determine which park characteristics had significant impacts on bird species richness. Results We found that park area, habitat diversity and the distance to city center were the best positive predictors of bird species richness in Nanjing urban parks. By contrast, park isolation, park shape and environmental noise had little or no influence on bird diversity. Conclusions Our study highlights the importance of park area, habitat diversity and the distance to city center in determining bird diversity in Nanjing city parks. Therefore, from a conservation viewpoint, we recommend that large parks with complex and diverse habitats far away from the city center should be retained or constructed to increase bird diversity in urban design and planning.


Sign in / Sign up

Export Citation Format

Share Document