Bird occupancy and richness in ponderosa pine forests with contrasting forest structure and fire historyThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

2008 ◽  
Vol 38 (5) ◽  
pp. 936-942 ◽  
Author(s):  
T. Luke George ◽  
Steve Zack
Keyword(s):  
Species Richness ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Bird Species ◽  
Bird Community ◽  
American Robin ◽  
Point Counts ◽  
Ponderosa Pine Forests ◽  
Silvicultural Treatments ◽  
Silvicultural Treatment

We compared the effects of two contrasting silvicultural treatments and prescribed fire on bird occupancy at Blacks Mountain Experimental Forest. Each silvicultural treatment was applied to two approximately 100 ha units within each of three blocks. Prescribed burning was applied to one-half of each silvicultural treatment in a split-plot design. Occupancy was estimated at eight points in each plot for 11 bird species and three foraging guilds (bark gleaners, woodpeckers, and foliage gleaners). The frequencies of species detections on the point counts were used to estimate species richness on each plot. Occupancy did not differ among treatments for any of the guilds. Four of the 11 bird species, the American robin ( Turdus migratorius L., 1766), the chipping sparrow ( Spizella passerina (Bechstein, 1798)), the white-breasted nuthatch ( Sitta carolinensis Latham, 1790), and the western tanager ( Piranga ludoviciana (A. Wilson, 1811)), showed responses to the treatments. Species richness did not differ between the silvicultural or the burn treatments. The general lack of response of the bird community to the silvicultural and burn treatments is likely a result of the relatively large size of the trees and snags retained on both silvicultural treatments, the low intensity of the prescribed burns, and the lack of a strong contrast in tree density between the silvicultural treatments.

scholarly journals Congruence between breeding and wintering biodiversity hotspots: A case study in farmlands of Western Poland

2019 ◽  
Vol 4 (2) ◽  
pp. 75-83
Author(s):  
Federico Morelli ◽  
Zbigniew Kwieciński ◽  
Piotr Indykiewicz ◽  
Łukasz Jankowiak ◽  
Paweł Szymański ◽  
...  
Keyword(s):  
Species Richness ◽  
Protected Areas ◽  
Functional Diversity ◽  
Conservation Status ◽  
Bird Species ◽  
Bird Community ◽  
Bird Diversity ◽  
Human Beings ◽  
Complete Representation ◽  
Evolutionary Distinctiveness

Abstract Farmland landscapes are recognized as important ecosystems, not only for their rich biodiversity but equally so for the human beings who live and work in these places. However, biodiversity varies among sites (spatial change) and among seasons (temporal change). In this work, we tested the hypothesis that bird diversity hotspots distribution for breeding is congruent with bird diversity hotspots for wintering season, focusing also the representation of protected areas for the conservation of local hotspots. We proposed a framework based on the use of species richness, functional diversity, and evolutionary distinctiveness to characterize avian communities. Although our findings show that the spatial distribution of local bird hotspots differed slightly between seasons, the protected areas’ representation was similar in both seasons. Protected areas covered 65% of the most important zones for breeding and 71% for the wintering season in the farmland studied. Functional diversity showed similar patterns as did bird species richness, but this measure can be most effective for highlighting differences on bird community composition. Evolutionary distinctiveness was less congruent with species richness and functional diversity, among seasons. Our findings suggest that inter-seasonal spatial congruence of local hotspots can be considered as suitable areas upon which to concentrate greater conservation efforts. However, even considering the relative congruence of avian diversity metrics at a local spatial scale, simultaneous analysis of protected areas while inter-seasonally considering hotspots, can provide a more complete representation of ecosystems for assessing the conservation status and designating priority areas.

Overlap in avian communities produces unimodal richness peaks on Bornean mountains

2018 ◽  
Vol 34 (2) ◽  
pp. 75-92 ◽  
Author(s):  
Ryan C. Burner ◽  
Alison R. Styring ◽  
Chandradewana Boer ◽  
Frederick H. Sheldon
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Sufficient Evidence ◽  
Altitudinal Distribution ◽  
Bird Species Richness ◽  
Point Counts ◽  
Habitat Gradient ◽  
Quantitative Analyses ◽  
Meta Analyses ◽  
Replicated Systems

Abstract:Altitudinal gradients provide tractable, replicated systems in which to study changes in species richness and community composition over relatively short distances. Previously, richness was often assumed to follow a monotonic decline with altitude, but recent meta-analyses show that more complex patterns, including mid-altitude richness peaks, are also prevalent in birds. In this study, we used point counts to survey birds at multiple altitudes on three mountains on the island of Borneo in Sundaland, an area for which quantitative analyses of avian altitudinal distribution are unavailable. In total we conducted 1088 point counts and collected associated habitat data at 527 locations to estimate species richness by altitude on Mt Mulu (2376 m), Mt Pueh (1550 m) and Mt Topap Oso (1450 m). On Mulu, the only mountain with an intact habitat gradient, bird species richness peaks at 600 m. Richness appeared to peak at 600 m on Totap Oso as well, but on Pueh it peaked several hundred metres higher. The richness peak on Mulu differs from that predicted by null models and is instead caused by the overlap of distinct lowland and montane avifaunas, supporting the faunal overlap hypothesis. This finding provides further evidence that a lack of coincidence between peak turnover and peak richness is not sufficient evidence to rule out faunal overlap as a causal factor.

scholarly journals Limited Effects of Long-Term Repeated Season and Interval of Prescribed Burning on Understory Vegetation Compositional Trajectories and Indicator Species in Ponderosa Pine Forests of Northeastern Oregon, USA

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 834
Author(s):  
Harold S. J. Zald ◽  
Becky K. Kerns ◽  
Michelle A. Day
Keyword(s):  
Indicator Species ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Vascular Plant ◽  
Fire Behavior ◽  
Understory Vegetation ◽  
Forest Composition ◽  
Forest Fuels ◽  
Ponderosa Pine Forests ◽  
Over Time

Fire exclusion has dramatically altered historically fire adapted forests across western North America. In response, forest managers reduce forest fuels with mechanical thinning and/or prescribed burning to alter fire behavior, with additional objectives of restoring forest composition, structure, and ecosystem processes. There has been extensive research on the effects of fuel reduction and restoration treatments on trees, fuels, regeneration, and fire behavior; but less is known about how these treatments influence understory vegetation, which contains the majority of vascular plant diversity in many dry conifer forests. Of particular interest is how understory vegetation may respond to the season and interval of prescribed burning. The season and interval of prescribed burning is often determined by operational constraints rather than historical fire regimes, potentially resulting in fire conditions and burn intervals to which native plants are poorly adapted. In this study, we examined how understory vegetation has responded to season and interval of prescribed burning in ponderosa pine (Pinus ponderosa) forests in the Blue Mountains of northeastern Oregon, USA. Using over a decade (2002–2015) of understory vegetation data collected in stands with different intervals (5 versus 15 year) and seasons (spring versus fall) of prescribed burning, we quantified how season and interval of prescribed burning has influenced understory vegetation compositional trajectories and indicator species over time. Season of prescribed burning resulted in different understory communities and distinct trajectories of understory composition over time, but interval of burning did not. Indicator species analysis suggests fall burning is facilitating early seral species, with native annual forbs displaying ephemeral responses to frequent burning, while invasive cheatgrass (Bromus tectorum) increased in abundance and frequency across all treatments over time. These findings indicate that understory vegetation in these ecosystems are sensitive to seasonality of burning, but the responses are subtle. Our findings suggest season and interval of prescribed burning used in this study do not result in large changes in understory vegetation community composition, a key consideration as land managers increase the pace and scale of prescribed fire in these forests.

scholarly journals Thinning and Burning Effects on Long-Term Litter Accumulation and Function in Young Ponderosa Pine Forests

2020 ◽  
Vol 66 (6) ◽  
pp. 761-769
Author(s):  
Matt Busse ◽  
Ross Gerrard
Keyword(s):  
Ponderosa Pine ◽  
Forest Floor ◽  
Prescribed Burning ◽  
Mineral Soil ◽  
Pine Forests ◽  
Organic Layer ◽  
Litter Accumulation ◽  
Ponderosa Pine Forests ◽  
Essential Components

Abstract We measured forest-floor accumulation in ponderosa pine forests of central Oregon and asked whether selected ecological functions of the organic layer were altered by thinning and repeated burning. Experimental treatments included three thinning methods applied in 1989 (stem only, whole tree, no thin—control) in factorial combination with prescribed burning (spring 1991 and repeated in 2002; no burn—control). Forest-floor depth and mass were measured every 4–6 years from 1991 to 2015. Without fire, there was little temporal change in depth or mass for thinned (270 trees ha−1) and control (560–615 trees ha−1) treatments, indicating balanced litterfall and decay rates across these stand densities. Each burn consumed 50–70 percent of the forest floor, yet unlike thinning, postfire accumulation rates were fairly rapid, with forest-floor depth matching preburn levels within 15–20 years. Few differences in forest-floor function (litter decay, carbon storage, physical barrier restricting plant emergence, erosion protection) resulted from thinning or burning after 25 years. An exception was the loss of approximately 300 kg N ha−1 because of repeated burning, or approximately 13 percent of the total site N. This study documents long-term forest-floor development and suggests that common silvicultural practices pose few risks to organic layer functions in these forests. Study Implications: Mechanical thinning and prescribed fire are among the most widespread management practices used to restore forests in the western US to healthy, firewise conditions. We evaluated their effects on the long-term development of litter and duff layers, which serve dual roles as essential components of soil health and as fuel for potential wildfire. Our study showed that thinning and burning provided effective fuel reduction and resulted in no adverse effects to soil quality in dry ponderosa pine forests of central Oregon. Repeated burning reduced the site carbon and nitrogen pools approximately 9–13 percent, which is small compared to C located in tree biomass and N in mineral soil. Litter accumulation after burning was rapid, and we recommend burning on at least a 15–20-year cycle to limit its build-up.

scholarly journals Influence of Land-Use Type on Forest Bird Community Composition in Mount Kenya Forest

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Samuel N. Mahiga ◽  
Paul Webala ◽  
Mugo J. Mware ◽  
Paul K. Ndang’ang’a
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Bird Community ◽  
Natural Forest ◽  
Forest Biodiversity ◽  
Natural Forests ◽  
Plantation Forest ◽  
Point Counts ◽  
Plantation Forests ◽  
Relative Species Richness

Few studies have explored how human land uses influence and support persistence of forest biodiversity in central Kenya. In the case of the Mount Kenya ecosystem, farmlands and plantation forests are significant land-use types. Using point counts, we assessed bird communities in natural forests, plantation forests, and farmlands in the Nanyuki Forest Block, Western Mount Kenya. Bird point counts were undertaken during two sampling periods (wet and dry season). Compared to farmlands and plantation forest, natural forest had the highest overall avian species richness and relative species richness of all except one forest-dependent foraging guild (granivores) and nonforest species, which occurred frequently only on farmlands. Plantation forest had the lowest relative richness of all avian habitat and foraging guilds. Conversely, specialist forest-dependent species mainly occurred in the structurally complex remnant natural forest. Our study underscores the importance of remnant natural forests for the persistence and conservation of forest biodiversity and risks posed by replacing them with plantation forests and farmlands.

Powerline easements through forests: a case study of impacts on avifauna

1998 ◽  
Vol 4 (1) ◽  
pp. 79 ◽  
Author(s):  
Jack Baker ◽  
Ross L. Goldingay ◽  
Robert J. Whelan
Keyword(s):  
Species Richness ◽  
Bird Community ◽  
Forest Habitat ◽  
Bird Abundance ◽  
Point Counts ◽  
Southeastern Australia ◽  
Total Species Richness ◽  
New Type ◽  
Forest Values

Powerline easements are typically a strip cleared of trees and tall vegetation to a width of approximately 50 m. They may affect avifauna by modification and fragmentation of forest habitat. We investigated the responses of the bird community to easements at three sites in southeastern Australia using 25 m radius point-counts spaced at 50 m intervals from the easement to 300 m inside the forest. The easements caused an absolute loss of habitat for forest avifauna, with abundance and species richness at the easement less than 20% of the forest values. Four species of easement opportunist and one easement specialist provided evidence that the easement represented a new type of habitat for avifauna. A barrier effect of fragmentation may occur for four species of easement avoiders. These were small to medium-sized terrestrial birds associated with dense ground and/or understorey cover. The edge effect of fragmentation was an adverse impact on forest avifauna. At the margin (25?125 m from the easement) of the forest, bird abundance, mean species richness and total species richness were significantly less than the corresponding values for the interior (225?325 m) of the forest. The mean abundance at the sites varied from 13.0?17.7 birds/ha and the species richness varied significantly among sites. The adverse impacts of powerline easements on native avifauna could be minimized by site-specific management which includes strategies to minimize the loss of forest habitat and to ameliorate the effects of fragmentation.

scholarly journals Mangrove bird community of Paranaguá Bay - Paraná, Brazil

2007 ◽  
Vol 50 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Luiz Augusto Macedo Mestre ◽  
Ricardo Krul ◽  
Valéria dos Santos Moraes
Keyword(s):  
Human Impacts ◽  
Bird Species ◽  
Passer Domesticus ◽  
Bird Community ◽  
Abundant Species ◽  
Marine Conservation ◽  
Point Counts ◽  
Flying Insects ◽  
Paranaguá Bay ◽  
Conservation Plans

This study describes the mangrove bird community of Paranaguá Bay in Paraná - South Brazil. Seasonal surveys were conducted during September 1997 to September 1998 at three sites in Paranaguá Bay. Frequencies and abundances of birds were registered in 200m transects and one hour point counts. A total of 81 bird species were observed in the three sampling sites. Most of the bird species in Paranaguá mangroves are fruits, seeds and arthropods consumers, and predators of flying insects. The most frequent and abundant species were Egretta caerulea, Ceryle torquata, Chloroceryle amazona, Pitangus sulphuratus, Turdus amaurochalinus and Parula pitiayumi. The bird community of these three sites is composed mainly by forest bird species. The mangroves of Paranaguá Bay shelter one of the richest avifauna of Brazilian mangroves. Differences between sampling sites could be related to the proximity of the Paranaguá city and human impacts in the areas. Only in the most disturbed site were observed Passer domesticus and large flocks of Coragyps atratus. This study contributed to the knowledge of mangrove communities, and could be an important basis to fluvial-marine conservation plans in Paraná- Brazil.

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.

scholarly journals Spatial and Temporal Dependency of NDVI Satellite Imagery in Predicting Bird Diversity over France

2018 ◽  
Vol 10 (7) ◽  
pp. 1136 ◽  
Author(s):  
Sébastien Bonthoux ◽  
Solenne Lefèvre ◽  
Pierre-Alexis Herrault ◽  
David Sheeren
Keyword(s):  
Species Richness ◽  
Satellite Imagery ◽  
Bird Species ◽  
Bird Community ◽  
Additive Models ◽  
Landscape Patterns ◽  
Community Patterns ◽  
Bird Species Richness ◽  
Acquisition Period ◽  
Time Period

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.

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