Patterns of breeding bird abundance in relation to logging in western Labrador

2000 ◽  
Vol 30 (2) ◽  
pp. 257-263 ◽  
Author(s):  
NPP Simon ◽  
F E Schwab ◽  
A W Diamond

We enumerated breeding birds by territorial mapping on harvested (scarified following burning and clear-cutting, clearcut following burning, and two intensities of selective logging, 39 and 71% residual forest canopy) and unharvested forests in western Labrador. Clear-cutting and postclearcut scarification substantially altered the suite of birds occupying forested areas. Logging that conserved 39% of the wood volume decreased some forest bird densities and increased some early successional bird densities in approximately equal proportions. Logging that conserved 71% of forest cover increased bird densities by increasing some early successional bird densities without reducing forest bird densities. Given the rarity of productive forests in western Labrador, <5% of the forest base, if they are logged, then at least 71% of the wood volume should be conserved.

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1542
Author(s):  
Nadezhda V. Genikova ◽  
Viktor N. Mamontov ◽  
Alexander M. Kryshen ◽  
Vladimir A. Kharitonov ◽  
Sergey A. Moshnikov ◽  
...  

Bilberry spruce forests are the most widespread forest type in the European boreal zone. Limiting the clear-cuttings size leads to fragmentation of forest cover and the appearance of large areas of ecotone complexes, composed of forest (F), a transition from forest to the cut-over site under tree canopy (FE), a transition from forest to the cut-over site beyond tree canopy (CE), and the actual clear-cut site (C). Natural regeneration of woody species (spruce, birch, rowan) in the bilberry spruce stand—clear-cut ecotone complex was studied during the first decade after logging. The effects produced by the time since cutting, forest edge aspect, and the ground cover on the emergence and growth of trees and shrubs under forest canopy and openly in the clear-cut were investigated. Estimating the amount and size of different species in the regeneration showed FE and CE width to be 8 m—roughly half the height of first-story trees. Typical forest conditions (F) feature a relatively small amount of regenerating spruce and birch. The most favorable conditions for natural regeneration of spruce in the clear-cut—mature bilberry spruce stand ecotone are at the forest edge in areas of transition both towards the forest and towards the clear-cut (FE and CE). Clear-cut areas farther from the forest edge (C) offer an advantage to regenerating birch, which grows densely and actively in this area.


The Condor ◽  
2003 ◽  
Vol 105 (2) ◽  
pp. 288-302 ◽  
Author(s):  
Lori A. Hennings ◽  
W. Daniel Edge

Abstract In 1999, we surveyed breeding bird and plant communities along 54 streams in the Portland, Oregon, metropolitan region to link bird community metrics with structural and spatial characteristics of urban riparian areas. Canonical correspondence analysis produced two explanatory axes relating to vegetation and road density. Total and non-native bird abundance was higher in narrow forests. Native bird abundance was greater in narrow forests surrounded by undeveloped lands; native species richness and diversity were greater in less-developed areas. Native resident and short-distance-migrant abundance was higher in narrow forests, and diversity was positively associated with developed lands. Neotropical migrant abundance, richness, and diversity were greater in open-canopied areas with fewer roads. We examined spatial relationships by regressing bird variables on satellite-derived forest canopy cover, area of undeveloped lands, and street density in a series of 50-m buffers within a 500-m radius around study sites. Non-native bird abundance decreased with increasing canopy cover within 450 m, but most other relationships were strongest at smaller scales (50–100 m). Our results suggest that increasing urban canopy cover is the most valuable land management action for conserving native breeding birds. A hierarchical scheme for Neotropical migrant conservation might include increasing forest canopy within 450 m of streams to control non-native species and cowbirds; reducing street density within a 100-m radius of streams; and conserving or planting onsite native trees and shrubs. Estructura de Comunidades Riparias de Aves en Portland, Oregon: Hábitat, Urbanización y Patrones de Escala Espacial Resumen. Censamos las comunidades de aves reproductivas y plantas a lo largo de 54 arroyos en el área metropolitana de Portland, Oregon en 1999 para conectar medidas de comunidades de aves con características estructurales y espaciales de zonas riparias urbanas. Análisis de correspondencia canónica produjeron dos ejes explicativos relacionados con la vegetación y la densidad de carreteras. La abundancia total de aves y la de aves no nativas fueron mayores en bosques estrechos. La abundancia de aves nativas fue mayor en bosques estrechos rodeados por terrenos rurales y la riqueza y diversidad de especies fueron mayores en áreas menos desarrolladas. La abundancia de residentes nativas y migratorias de corta distancia fue mayor en bosques estrechos y su diversidad estuvo asociada positivamente con terrenos desarrollados. La abundancia, riqueza y diversidad de las migratorias neotropicales fueron mayores en áreas de dosel abierto y con pocas carreteras. Examinamos las relaciones espaciales mediante regresiones entre variables de aves y la cobertura del dosel derivada de imágenes satelitales, el área de terrenos sin desarrollar y la densidad de calles en una serie de áreas de 50 m de ancho en un radio de 500 m alrededor de los sitios de estudio. La abundancia de aves no nativas disminuyó con aumentos en la cobertura del dosel hasta 450 m, pero la mayoría de las demás relaciones fueron más fuertes a escalas menores (50–100 m). Nuestros resultados sugieren que el incremento de la cobertura del dosel en áreas urbanas es la estrategia de manejo más valiosa para conservar las aves nativas que se reproducen en el área. Un esquema jerárquico para la conservación de las migratorias neotropicales podría incluir aumentar la cobertura de bosque a menos de 450 m de los arroyos para controlar a las especies no nativas y a los Molothrus, reducir la densidad de calles dentro de un radio de 100 m alrededor de los arroyos y conservar o plantar árboles y arbustos nativos.


The Condor ◽  
2006 ◽  
Vol 108 (3) ◽  
pp. 691-699 ◽  
Author(s):  
Scott G. Somershoe ◽  
Daniel J. Twedt ◽  
Bruce Reid

Abstract We combined Breeding Bird Survey point count protocol and distance sampling to survey spring migrant and breeding birds in Vicksburg National Military Park on 33 days between March and June of 2003 and 2004. For 26 of 106 detected species, we used program DISTANCE to estimate detection probabilities and densities from 660 3-min point counts in which detections were recorded within four distance annuli. For most species, estimates of detection probability, and thereby density estimates, were improved through incorporation of the proportion of forest cover at point count locations as a covariate. Our results suggest Breeding Bird Surveys would benefit from the use of distance sampling and a quantitative characterization of habitat at point count locations. During spring migration, we estimated that the most common migrant species accounted for a population of 5000–9000 birds in Vicksburg National Military Park (636 ha). Species with average populations of >300 individuals during migration were: Blue-gray Gnatcatcher (Polioptila caerulea), Cedar Waxwing (Bombycilla cedrorum), White-eyed Vireo (Vireo griseus), Indigo Bunting (Passerina cyanea), and Ruby-crowned Kinglet (Regulus calendula). Of 56 species that bred in Vicksburg National Military Park, we estimated that the most common 18 species accounted for >8150 individuals. The six most abundant breeding species, Blue-gray Gnatcatcher, White-eyed Vireo, Summer Tanager (Piranga rubra), Northern Cardinal (Cardinalis cardinalis), Carolina Wren (Thryothorus ludovicianus), and Brown-headed Cowbird (Molothrus ater), accounted for >5800 individuals.


2014 ◽  
Vol 281 (1795) ◽  
pp. 20141742 ◽  
Author(s):  
Sadia E. Ahmed ◽  
Alexander C. Lees ◽  
Nárgila G. Moura ◽  
Toby A. Gardner ◽  
Jos Barlow ◽  
...  

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation.


2003 ◽  
Vol 79 (1) ◽  
pp. 132-146 ◽  
Author(s):  
Dennis Yemshanov ◽  
Ajith H Perera

We reviewed the published knowledge on forest succession in the North American boreal biome for its applicability in modelling forest cover change over large extents. At broader scales, forest succession can be viewed as forest cover change over time. Quantitative case studies of forest succession in peer-reviewed literature are reliable sources of information about changes in forest canopy composition. We reviewed the following aspects of forest succession in literature: disturbances; pathways of post-disturbance forest cover change; timing of successional steps; probabilities of post-disturbance forest cover change, and effects of geographic location and ecological site conditions on forest cover change. The results from studies in the literature, which were mostly based on sample plot observations, appeared to be sufficient to describe boreal forest cover change as a generalized discrete-state transition process, with the discrete states denoted by tree species dominance. In this paper, we outline an approach for incorporating published knowledge on forest succession into stochastic simulation models of boreal forest cover change in a standardized manner. We found that the lack of details in the literature on long-term forest succession, particularly on the influence of pre-disturbance forest cover composition, may be limiting factors in parameterizing simulation models. We suggest that the simulation models based on published information can provide a good foundation as null models, which can be further calibrated as detailed quantitative information on forest cover change becomes available. Key words: probabilistic model, transition matrix, boreal biome, landscape ecology


2021 ◽  
Vol 13 (14) ◽  
pp. 7539
Author(s):  
Zaw Naing Tun ◽  
Paul Dargusch ◽  
DJ McMoran ◽  
Clive McAlpine ◽  
Genia Hill

Myanmar is one of the most forested countries of mainland Southeast Asia and is a globally important biodiversity hotspot. However, forest cover has declined from 58% in 1990 to 44% in 2015. The aim of this paper was to understand the patterns and drivers of deforestation and forest degradation in Myanmar since 2005, and to identify possible policy interventions for improving Myanmar’s forest management. Remote sensing derived land cover maps of 2005, 2010 and 2015 were accessed from the Forest Department, Myanmar. Post-classification change detection analysis and cross tabulation were completed using spatial analyst and map algebra tools in ArcGIS (10.6) software. The results showed the overall annual rate of forest cover loss was 2.58% between 2005 and 2010, but declined to 0.97% between 2010 and 2015. The change detection analysis showed that deforestation in Myanmar occurred mainly through the degradation of forest canopy associated with logging rather than forest clearing. We propose that strengthening the protected area system in Myanmar, and community participation in forest conservation and management. There needs to be a reduction in centralisation of forestry management by sharing responsibilities with local governments and the movement away from corruption in the timber trading industry through the formation of local-based small and medium enterprises. We also recommend the development of a forest monitoring program using advanced remote sensing and GIS technologies.


1985 ◽  
Vol 61 (5) ◽  
pp. 351-357 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Marius Pineau ◽  
Louis Bélanger

Much of the deterioration observed on many campgrounds in forested areas is closely linked to the presence of the camper. Thus, ground flora cover and composition, forest cover density and vigour, soil density and permeability are affected. Appropriate actions could be taken to reduce undesirable alterations: proper site selection, concentration of the utilization, deterioration monitoring, treatment of the vegetation and modification of the camper's behaviour. Key words: camping; recreation, impact.


2011 ◽  
Vol 7 (4) ◽  
pp. 506-509 ◽  
Author(s):  
Thomas B. Ryder ◽  
Brent M. Horton ◽  
Ignacio T. Moore

Male reproductive coalitions, in which males cooperate to attract females, are a rare strategy among vertebrates. While some studies have investigated ultimate aspects of these relationships, little is known about the mechanistic role that hormones play in modulating cooperative behaviours. Here, we examined male testosterone variation in a tropical lekking bird, the wire-tailed manakin ( Pipra filicauda ), which exhibits cooperative male–male display coalitions. We found that testosterone levels in territorial males were comparable to those of temperate breeding birds, a surprising result given their environmental, social and reproductive dynamics. In addition, social status rather than plumage was a strong predictor of testosterone variation. Territorial males had significantly higher testosterone levels than did two other plumage classes of floater males, who do not hold territories. We hypothesize that testosterone variation plays an important role in the establishment of male dominance hierarchies (competition), while concurrently facilitating stable display partnerships (cooperation).


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 75
Author(s):  
Irene Pellegrino ◽  
Luca Ilahiane ◽  
Giovanni Boano ◽  
Marco Cucco ◽  
Marco Pavia ◽  
...  

The Western Palearctic is one of the most investigated regions for avian haemosporidian parasites (Haemoproteus, Plasmodium and Leucocytozoon), yet geographic gaps in our regional knowledge remain. Here, we report the first haemosporidian screening of the breeding birds from Sardinia (the second-largest Mediterranean Island and a biodiversity hotspot), and the first for the insular Mediterranean in general. We examined the occurrence of haemosporidians by amplifying their mtDNA cytb gene in 217 breeding birds, belonging to 32 species. The total prevalence of infected birds was 55.3%, and of the 116 haplotypes recovered, 84 were novel. Despite the high number of novel lineages, phylogenetic analysis did not highlight Sardinia-specific clades; instead, some Sardinian lineages were more closely related to lineages previously recovered from continental Europe. Host-parasite network analysis indicated a specialized host-parasite community. Binomial generalized linear models (GLMs), performed at the community level, suggested an elevational effect on haemosporidian occurrence probability (negative for Haemoproteus; positive for Leucocytozoon) likely due to differences in the abundance of insect vectors at different elevations. Furthermore, a GLM revealed that sedentary birds showed a higher probability of being infected by novel haplotypes and long-distance migrants showed a lower probability of novel haplotype infection. We hypothesize that the high diversity of haemosporidians is linked to the isolation of breeding bird populations on Sardinia. This study adds to the growing knowledge on haemosporidians lineage diversity and distribution in insular environments and presents new insights on potential host-parasite associations.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10621
Author(s):  
Pascale Schuit ◽  
Justin Moat ◽  
Tadesse Woldemariam Gole ◽  
Zeleke Kebebew Challa ◽  
Jeremy Torz ◽  
...  

The specialty coffee sector represents opportunities for coffee farmers and other actors due to increased value within the supply chain, driven by elevated consumer purchase prices. We investigated these relationships up to the export stage, as well as the potential for specialty coffee to improve stakeholder participation in biodiversity conservation. Household data was collected from a sample of 272 coffee farmers belonging to five primary cooperatives, in the heavily forested area of Yayu, in the Illubabor administrative zone of Oromia regional state in south-western Ethiopia, for the 2017/2018 harvest season. Qualitative and quantitative data, gathered between 2015 and 2019, from focus group discussions, was used to supplement the survey and to explain the empirical findings. We show that the income from coffee (and thus household income) can be increased, in some cases substantially, via participation in the specialty coffee market. The unit price for coffee was much higher than standard market prices and those including certification premiums. Whilst quality is a key factor for specialty coffee, income increases via the specialty market are caveat bound. In particular, there is a critical requirement for efficient and effective cooperative management, and we provide suggestions for improvements. In the long-term, more focus is needed to increase the financial and human capacities of Ethiopian coffee cooperatives, to make them more effective partners in the specialty coffee value chain. The high conversion rates from harvested to clean exportable specialty coffee (8:1, or higher) is identified as a major constraint on profitability. We show that specialty coffee can bring about positive environmental benefits. Elevating coffee prices and farm profitability to bring household income levels to around or above the global poverty line may ensure the continuation of forest coffee production, and thus the retention of forest. The increases in income via specialty coffee production, reported in the study, were achieved without increasing land use or the application of environmentally costly inputs. Moreover, analysis of satellite data shows that a large proportion of the coffee farms surveyed retain a level of forest cover and quality approaching primary (undisturbed) forest, and that the coffee production area at Yayu has not experienced any significant deforestation (since 2000). We recommend that coffee premiums linked to environmental benefit should demonstrate clearly defined and appropriate metrics, as we have demonstrated here for forest (canopy) quality and coverage (area).


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