scholarly journals When bigger isn’t better – implications of large high-severity wildfire patches on avian diversity and community composition

2020 ◽  
Author(s):  
Zachary Steel ◽  
Alissa Fogg ◽  
Ryan Burnett ◽  
L. Jay Roberts ◽  
Hugh Safford
Keyword(s):  
Community Composition ◽  
Patch Size ◽  
Full Range ◽  
Fire Effects ◽  
Bird Diversity ◽  
Avian Diversity ◽  
Imperfect Detection ◽  
Forest Fuels ◽  
High Severity ◽  
Management Actions

Aim: Modern wildfires increasingly create large high-severity patches with interior areas far from less disturbed habitats. We evaluated how these trends impact montane bird communities by investigating the effect of internal distance to lower severity areas, high-severity patch size, and years since fire on avian alpha and beta diversity.Location:Sierra Nevada Mountains, California, USAMethods:Bird occurrence data were collected during 2009-2017 within high-severity patches of 27 wildfires representing 1-30 years since disturbance. A two-step multispecies occupancy method was used to account for imperfect detection of 94 species and estimate effects of high-severity patch characteristics on community richness and dissimilarity as well as richness of nesting guilds. Results:Community richness decreased with distance from patch edge and with high-severity patch size. Richness increased with years since fire, but this pattern was mediated by distance to edge with higher peak richness (23 species) on the patch edges than interiors (18 species). Community dissimilarity was not explained by distance from edge or patch area indicating that interiors of large high-severity patches contain a subset of rather than a complement to the edge community. Guild richness of tree and primary cavity nesters was negatively associated with distance and patch size. Richness of ground and shrub nesters was insensitive to these metrics but due to declines among other species, the groups made up a greater percentage of the avian community within patch interiors.Main conclusions:As fire activity increases due to accumulating forest fuels and accelerating climate change, high-severity patches and their resulting early-seral habitats are becoming more extensive with less edge and more interior area. Such changes are likely to decrease avian diversity locally and shift community composition away from forest-associated species. Management actions that promote the full range of fire effects but limit the size of high-severity patches may best conserve bird diversity within fire-adapted ecosystems.

scholarly journals When bigger isn’t better—Implications of large high‐severity wildfire patches for avian diversity and community composition

2021 ◽  
Author(s):  
Zachary L. Steel ◽  
Alissa M. Fogg ◽  
Ryan Burnett ◽  
L. Jay Roberts ◽  
Hugh D. Safford
Keyword(s):  
Community Composition ◽  
Avian Diversity ◽  
High Severity

scholarly journals Population estimates of Antillean manatees in Puerto Rico: an analytical framework for aerial surveys using multi-pass removal sampling

2019 ◽  
Vol 100 (4) ◽  
pp. 1340-1349
Author(s):  
Jaime A Collazo ◽  
Matthew J Krachey ◽  
Kenneth H Pollock ◽  
Francisco J Pérez-Aguilo ◽  
Jan P Zegarra ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Detection Probability ◽  
Analytical Framework ◽  
Population Estimates ◽  
High Concentration ◽  
Imperfect Detection ◽  
Factors Affecting ◽  
Management Actions ◽  
Aerial Surveys ◽  
Population Size Estimates

AbstractEffective management of the threatened Antillean manatee (Trichechus manatus manatus) in Puerto Rico requires reliable estimates of population size. Estimates are needed to assess population responses to management actions, and whether recovery objectives have been met. Aerial surveys have been conducted since 1976, but none adjusted for imperfect detection. We summarize surveys since 1976, report on current distribution, and provide population estimates after accounting for apparent detection probability for surveys between June 2010 and March 2014. Estimates in areas of high concentration (hotspots) averaged 317 ± 101, three times higher than unadjusted counts (104 ± 0.56). Adjusted estimates in three areas outside hotspots also differed markedly from counts (75 ± 9.89 versus 19.5 ± 3.5). Average minimum island-wide estimate was 386 ± 89, similar to the maximum estimate of 360 suggested in 2005, but fewer than the 700 recently suggested by the Puerto Rico Manatee Conservation Center. Manatees were more widespread than previously understood. Improving estimates, locally or island-wide, will require stratifying the island differently and greater knowledge about factors affecting detection probability. Sharing our protocol with partners in nearby islands (e.g., Cuba, Jamaica, Hispaniola), whose populations share genetic make-up, would contribute to enhanced regional conservation through better population estimates and tracking range expansion.El manejo efectivo del manatí antillano amenazado en Puerto Rico requiere estimados de tamaños de poblaciónes confiables. Dichas estimaciones poblacionales son necesarias para evaluar las respuestas a las acciones de manejo, y para determinar si los objetivos de recuperación han sido alcanzados. Se han realizado censos aéreos desde 1976, pero ninguno de ellos han sido ajustados para detecciones imperfectas. Aquí resumimos los censos desde 1976, actualizamos la distribución, y reportamos los primeros estimados poblacionales ajustados para la probabilidad de detección aparente en los censos de Junio 2010 a Marzo 2014. Las estimaciones poblacionales en áreas de mayor concentración del manatí promedió 317 ± 103, tres veces más abundante que los conteos sin ajuste (104 ± 0.56). Las estimaciones poblacionales en tres áreas fuera de las áreas de mayor concentración del manatí también fueron marcadamente diferentes (75 ± 9.89 vs 19.5 ± 3.5). El estimado mínimo poblacional en la isla entera fue de 386 ± 89, similar al estimado máximo de 360 sugerido en el año 2005, pero menor a los 700 sugeridos recientemente por el Centro de Conservación de Manatíes de Puerto Rico. Documentamos que el manatí tiene una distribución más amplia de lo que se sabía con anterioridad. El mejoramiento de los estimados poblacionales locales o a nivel de isla requerirá que se estratifique a la isla en forma diferente y que se investiguen los factores que influencian a la probabilidad de detección. Compartir protocolos como este con colaboradores de islas vecinas (por. ej., Cuba, Jamaica, Española), cuyas poblaciones de manatíes comparten material genético, contribuiría a la conservación regional mediante mejores estimaciones poblacionales y monitoreo de la expansión de su ámbito doméstico.

Is the END (emulation of natural disturbance) a new beginning? A critical analysis of the use of fire regimes as the basis of forest ecosystem management with examples from the Canadian western Cordillera

2016 ◽  
Vol 24 (3) ◽  
pp. 233-243 ◽  
Author(s):  
Chris Stockdale ◽  
Mike Flannigan ◽  
Ellen Macdonald
Keyword(s):  
Forest Management ◽  
Ecosystem Management ◽  
Forest Structure ◽  
Fire Regime ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Disturbance Regime ◽  
Ecological Processes ◽  
High Severity ◽  
Management Actions

As our view of disturbances such as wildfire has shifted from prevention to recognizing their ecological necessity, so too forest management has evolved from timber-focused even-aged management to more holistic paradigms like ecosystem-based management. Emulation of natural disturbance (END) is a variant of ecosystem management that recognizes the importance of disturbance for maintaining ecological integrity. For END to be a successful model for forest management we need to describe disturbance regimes and implement management actions that emulate them, in turn achieving our objectives for forest structure and function. We review the different components of fire regimes (cause, frequency, extent, timing, and magnitude), we describe low-, mixed-, and high-severity fire regimes, and we discuss key issues related to describing these regimes. When characterizing fire regimes, different methods and spatial and temporal extents result in wide variation of estimates for different fire regime components. Comparing studies is difficult as few measure the same components; some methods are based on the assumption of a high-severity fire regime and are not suited to detecting mixed- or low-severity regimes, which are critical to END management, as this would affect retention in harvested areas. We outline some difficulties with using fire regimes as coarse filters for forest management, including (i) not fully understanding the interactions between fire and other disturbance agents, (ii) assuming that fire is strictly an exogenous disturbance agent that exerts top-down control of forest structure while ignoring numerous endogenous and bottom-up feedbacks on fire effects, and (iii) assuming by only replicating natural disturbance patterns we preserve ecological processes and vital ecosystem components. Even with a good understanding of a fire regime, we would still be challenged with choosing the temporal and spatial scope for the disturbance regime we are trying to emulate. We cannot yet define forest conditions that will arise from variations in disturbance regime; this then limits our ability to implement management actions that will achieve those conditions. We end by highlighting some important knowledge gaps about fire regimes and how the END model could be strengthened to achieve a more sustainable form of forest management.

scholarly journals Fire effects on the composition of a bird community in an amazonian Savanna (Brazil)

2005 ◽  
Vol 65 (4) ◽  
pp. 683-695 ◽  
Author(s):  
R. Cintra ◽  
T. M. Sanaiotti
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Spatial Scales ◽  
Bird Species ◽  
Bird Community ◽  
Fire Effects ◽  
Bird Abundance ◽  
Bird Species Richness ◽  
Byrsonima Crassifolia ◽  
Mist Net

The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil). Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling) showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari) or fruiting trees (Byrsonima crassifolia). Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

Effect of patches of woody vegetation on the role of fire in tropical grasslands and savannas

2014 ◽  
Vol 23 (3) ◽  
pp. 410 ◽  
Author(s):  
Frank van Langevelde ◽  
Casper de Groot ◽  
Thomas A. Groen ◽  
Ignas M. A. Heitkönig ◽  
Ian Gaigher
Keyword(s):  
Patch Size ◽  
Fire Effects ◽  
Climatic Conditions ◽  
Windward Side ◽  
Woody Vegetation ◽  
Leeward Side ◽  
Tree Seedlings ◽  
Tropical Grasslands ◽  
Vegetation Expansion

In tropical grasslands and savannas, fire is used to reduce woody vegetation expansion. Woody vegetation in these biomes is often patchily distributed, and micro-climatic conditions can largely vary locally with unknown consequences for fire effects. We hypothesised that (1) fire has higher temperature and maintains high temperatures for a longer period at the windward side than at the leeward side of wooded patches, (2) this difference increases with patch size, (3) fire has a larger effect on woody vegetation at the windward side than at the leeward side of wooded patches and (4) this effect increases with patch size. We planted tree seedlings around wooded patches in a grassland and burnt these plots. We found that fire had a lower temperature and had an elevated temperature for a shorter time period at the leeward side of wooded patches than at the windward side. Also, we found smaller effect of fire on the seedlings at the leeward side. We conclude that patches of woody vegetation can have a large effect on the role of fire in tropical grasslands and savannas. This effect suggests a ‘safe zone’ for seedlings at the leeward side, which consequently promotes woody vegetation expansion. This paper contributes to understanding of the effect of patchiness of woody vegetation on the role of fire in tropical grasslands and savannas in reducing woody vegetation expansion.

scholarly journals Avifauna Survey within a University Campus and Adjacent Forest Fragment in Bicol, Eastern Philippines

2019 ◽  
pp. 84-95
Author(s):  
Jocelyn Serrano ◽  
Jonathan Guerrero ◽  
Josiah Quimpo ◽  
Giovani Andes ◽  
Erwin Bañares ◽  
...  
Keyword(s):  
Bird Species ◽  
Bird Diversity ◽  
University Campus ◽  
Avian Diversity ◽  
Forest Fragment ◽  
Point Count ◽  
Main Campus ◽  
Bird Survey ◽  
Baseline Information ◽  
Point Count Method

With the lack of baseline information on avifauna within Bicol University and the adjacent forest fragment, this research aimed to identify bird species and compare their presence between an urbanized and forest areas. Avian diversity was documented within the Kalikasan Park and Bicol University Main Campus adjacent ecosystems, representing a forest fragment and semi-urbanized ecosystems, respectively. Bird survey was carried out through point count method. Identification was aided by existing taxonomic keys. A total of 44 species were recorded with eleven as Philippine endemics. Lonchura malacca(Chestnut Munia) and Aplonis panayensis (Asian Glossy Starling) were among the most frequently sighted. Bird species sighted was higher in the forest fragment as compared with the main campus area. The study recommends that Bicol University Main campus be transformed into an avian buffer and safe zone for the protection and conservation of these species and to provide policies to maintain high bird diversity.

scholarly journals Avian Diversity of Oak Mixed Forest in Pauri Garhwal, Uttarakhand, India

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Jarnail Singh ◽  
Sunil Bhandari ◽  
M S Bisht
Keyword(s):  
Species Richness ◽  
Field Survey ◽  
Diversity Index ◽  
Mixed Forest ◽  
Bird Species ◽  
Bird Diversity ◽  
Species Evenness ◽  
Avian Diversity ◽  
Number Of Species

The avian diversity of Oak mixed forest in Pauri Garhwal district of Uttarakhand was studied during October 2019 to March 2020. Two strands of oak mixed forest located at different sites at 29º 22’-29º 75’ North and 78º, 10’ -78º,80’ East (1750 masl) were selected. Regular field survey was carried out during the morning and evening hours at each site. A total of 63 species of birds belonging to 07 orders and 31 families were recorded. The average bird diversity index H ¯was 3.202. The species richness was observed around 7.27 and species evenness was 0.72. The highest number of species was recorded at Ransi Oak mixed forest (63) and lowest number of bird species were recorded in Teka Oak mixed forest (60).

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