Songbird response to wildfire in mixed-conifer forest in south-western Oregon

2014 ◽  
Vol 23 (2) ◽  
pp. 246 ◽  
Author(s):  
Nathaniel E. Seavy ◽  
John D. Alexander
Keyword(s):  
Large Scale ◽  
Bird Species ◽  
Spatial And Temporal Variation ◽  
Spatial And Temporal Variability ◽  
Conifer Forest ◽  
Burned Areas ◽  
Mixed Conifer Forest ◽  
Broadleaf Species ◽  
Induced Changes ◽  
Nest Predators

We used 1 year of pre-fire and 4 years of post-fire data to quantify changes in the occurrence of birds at burned and unburned sites in a southern Oregon watershed after a 2500-ha wildfire. Our objectives were to identify bird species that increased or decreased as a result of this mixed-severity fire. Of the 27 species we investigated, we found evidence for fire-induced changes in the proportion of sites occupied by 13 species. Of these, most (8 species) were species that occurred at fewer sites after the fire than before. These changes were consistent with changes in vegetation composition, which included a decrease in the cover of conifer species and an increase in the cover of broadleaf species. To evaluate the effect of the fire on other ecological conditions, we compared the abundance of nest predators and potential prey items (arthropod biomass) between burned and unburned areas in the 3rd and 4th years after the fire. We found little evidence that the abundance of nest predators differed between burned and unburned areas in either year. There was, however, substantial spatial and temporal variation in arthropod abundance. Hemipteran and coleopteran biomass was greater in burned areas in both the 3rd and 4th year after the fire, and overall arthropod biomass was greater in the 4th year after the fire. The spatial and temporal variability in the bird response to this fire illustrates the importance of before–after–control–impact and multi-year studies for understanding the effects of large-scale disturbances on avian community composition.

Positive effects of fire on birds may appear only under narrow combinations of fire severity and time-since-fire

2016 ◽  
Vol 25 (10) ◽  
pp. 1074 ◽  
Author(s):  
Richard L. Hutto ◽  
David A. Patterson
Keyword(s):  
Management Practices ◽  
Fire Severity ◽  
Bird Species ◽  
Conifer Forest ◽  
Detection Rates ◽  
Salvage Logging ◽  
Beneficial Effects ◽  
Positive Effects ◽  
Time Since Fire ◽  
Mixed Conifer Forest

We conducted bird surveys in 10 of the first 11 years following a mixed-severity fire in a dry, low-elevation mixed-conifer forest in western Montana, United States. By defining fire in terms of fire severity and time-since-fire, and then comparing detection rates for species inside 15 combinations of fire severity and time-since-fire, with their rates of detection in unburned (but otherwise similar) forest outside the burn perimeter, we were able to assess more nuanced effects of fire on 50 bird species. A majority of species (60%) was detected significantly more frequently inside than outside the burn. It is likely that the beneficial effects of fire for some species can be detected only under relatively narrow combinations of fire severity and time-since-fire. Because most species responded positively and uniquely to some combination of fire severity and time-since-fire, these results carry important management implications. Specifically, the variety of burned-forest conditions required by fire-dependent bird species cannot be created through the application of relatively uniform low-severity prescribed fires, through land management practices that serve to reduce fire severity or through post-fire salvage logging, which removes the dead trees required by most disturbance-dependent bird species.

Evidence for bottom-up effects in the boreal forest: Do passerine birds respond to large-scale experimental fertilization?

1995 ◽  
Vol 73 (12) ◽  
pp. 2231-2237 ◽  
Author(s):  
Nicholas F. G. Folkard ◽  
James N. M. Smith
Keyword(s):  
Species Richness ◽  
Boreal Forest ◽  
Large Scale ◽  
Bird Species ◽  
Passerine Bird ◽  
Spatial And Temporal Variation ◽  
Bottom Up ◽  
Bird Species Richness ◽  
Point Counts ◽  
The Impact

Boreal plant communities are strongly nutrient limited, and the animals of the boreal forest may therefore experience bottom-up nutrient limitation. We conducted a 5-year experimental study of the impact of aerial nitrogen fertilization on birds of the boreal forest near Kluane Lake, southwestern Yukon, to test for such bottom-up effects. Specifically, we tested if avian abundance and species richness increased after fertilization. Variable circular-plot point counts were made to estimate bird numbers and species richness each summer from 1988 to 1992. Fertilization had no effect on abundance for the first two summers, but total abundances of the seven commonest passerine bird species increased by an average of 46% over the final 3 years. Fertilization had no effect on bird species richness. Population densities and species richness were both low at Kluane compared with patterns seen in temperate forest. Yellow-rumped warblers (Dendroica coronata), dark-eyed juncos (Junco hyemalis), and Swainson's thrushes (Catharus ustulatus) dominated the passerine community at Kluane. There was only moderate spatial and temporal variation in songbird numbers on control plots over the 5-year study period.

scholarly journals Evidence for a Relationship Between the Movements of the Common Redpoll (Acanthis flammea) and the American Goldfinch (Spinus tristis)

2018 ◽  
Vol 11 (1) ◽  
pp. 1-26
Author(s):  
Paul J. Dougherty ◽  
W. Herbert Wilson, Jr.
Keyword(s):  
North America ◽  
Large Scale ◽  
Bird Species ◽  
Spatial And Temporal Variation ◽  
Crop Failure ◽  
Northern Regions ◽  
Historic Data ◽  
The Common ◽  
Northern United States ◽  
Resource Levels

Background:Many bird species that breed at high latitudes exhibit irregular southward incursions in response to spatial and temporal variation in winter food availability.Methods:We analyzed Christmas Bird Count records to compare the migratory behavior of the Common Redpoll (Acanthis flammea), an Arctic breeder known to invade southern latitudes every other winter, with that of the American Goldfinch (Spinus tristis), a closely related finch species that breeds broadly in temperate latitudes in North America.Results and Discussion:Historic data indicate that east of the Rocky Mountains, both species overwinter in relatively even numbers across latitudes. In contrast, we found few significant positive correlations between the winter records of each species in different areas along the same longitude. We attribute these patterns to the fact that resource levels and environmental conditions tend to be similar across latitudes. While previous studies of historic data have identified a biennial pattern in the migration of the Common Redpoll, we found evidence that populations of American Goldfinches breeding in the northern parts of the species’ range similarly display significant southward movements every other year. Because these two species breed at different latitudes and show large-scale southward movements during the same years, areas across southern Canada and the northern United States alternate between having high winter abundances of Common Redpolls and American Goldfinches. We propose that these alternations are caused by a shared response to cyclical seed crop failure across the northern regions of North America.

scholarly journals Uni-Temporal Multispectral Imagery for Burned Area Mapping with Deep Learning

2021 ◽  
Vol 13 (8) ◽  
pp. 1509
Author(s):  
Xikun Hu ◽  
Yifang Ban ◽  
Andrea Nascetti
Keyword(s):  
Deep Learning ◽  
Large Scale ◽  
Multiple Scales ◽  
Detection Methods ◽  
Burned Area ◽  
Landsat 8 ◽  
Multispectral Imagery ◽  
Burned Areas ◽  
Local Climate Zones ◽  
Sentinel 2

Accurate burned area information is needed to assess the impacts of wildfires on people, communities, and natural ecosystems. Various burned area detection methods have been developed using satellite remote sensing measurements with wide coverage and frequent revisits. Our study aims to expound on the capability of deep learning (DL) models for automatically mapping burned areas from uni-temporal multispectral imagery. Specifically, several semantic segmentation network architectures, i.e., U-Net, HRNet, Fast-SCNN, and DeepLabv3+, and machine learning (ML) algorithms were applied to Sentinel-2 imagery and Landsat-8 imagery in three wildfire sites in two different local climate zones. The validation results show that the DL algorithms outperform the ML methods in two of the three cases with the compact burned scars, while ML methods seem to be more suitable for mapping dispersed burn in boreal forests. Using Sentinel-2 images, U-Net and HRNet exhibit comparatively identical performance with higher kappa (around 0.9) in one heterogeneous Mediterranean fire site in Greece; Fast-SCNN performs better than others with kappa over 0.79 in one compact boreal forest fire with various burn severity in Sweden. Furthermore, directly transferring the trained models to corresponding Landsat-8 data, HRNet dominates in the three test sites among DL models and can preserve the high accuracy. The results demonstrated that DL models can make full use of contextual information and capture spatial details in multiple scales from fire-sensitive spectral bands to map burned areas. Using only a post-fire image, the DL methods not only provide automatic, accurate, and bias-free large-scale mapping option with cross-sensor applicability, but also have potential to be used for onboard processing in the next Earth observation satellites.

scholarly journals Prevalence and genetic diversity of avian haemosporidian parasites in wild bird species of the order Columbiformes

2021 ◽  
Author(s):  
Yvonne R. Schumm ◽  
Dimitris Bakaloudis ◽  
Christos Barboutis ◽  
Jacopo G. Cecere ◽  
Cyril Eraud ◽  
...  
Keyword(s):  
Host Species ◽  
Large Scale ◽  
Phylogenetic Reconstruction ◽  
Bird Species ◽  
Avian Species ◽  
Blood Parasites ◽  
Migration Strategy ◽  
Haemosporidian Parasites ◽  
Multiplex Pcr Assay ◽  
And Migration

AbstractDiseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.

Spatial variability in microclimate in a mixed-conifer forest before and after thinning and burning treatments

2010 ◽  
Vol 259 (5) ◽  
pp. 904-915 ◽  
Author(s):  
Siyan Ma ◽  
Amy Concilio ◽  
Brian Oakley ◽  
Malcolm North ◽  
Jiquan Chen
Keyword(s):  
Spatial Variability ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Mixed Conifer Forest ◽  
Before And After

scholarly journals A Phylogenomic Supertree of Birds

Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 109 ◽  
Author(s):  
Rebecca T. Kimball ◽  
Carl H. Oliveros ◽  
Ning Wang ◽  
Noor D. White ◽  
F. Keith Barker ◽  
...  
Keyword(s):  
Large Scale ◽  
Sequence Data ◽  
Bird Species ◽  
Divide And Conquer ◽  
Clear Understanding ◽  
Whole Genome ◽  
Efficient Manner ◽  
Sequence Capture ◽  
Branch Lengths ◽  
Supertree Methods

It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.

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