Fire and its impact on avian population dynamics

1997 ◽  
Vol 3 (3) ◽  
pp. 206 ◽  
Author(s):  
G. Barry Baker ◽  
E. Belinda Dettmann ◽  
Stephen J. Wilson
Keyword(s):  
Population Size ◽  
Fire Regimes ◽  
Long Term Study ◽  
Sclerophyll Forest ◽  
In Fire ◽  
Avian Populations ◽  
The Impact ◽  
Term Monitoring ◽  
Probability Of Capture

Survival rate, population size, recruitment and probability of capture, derived from a long-term study of 20 passerine species in wet sclerophyll forest near Canberra, were used to measure the impact of a high intensity wildfire which burnt 70% of the study area. The wildfire significantly affected the population size of 13 species for a period of up to six years following the fire. Survival and recruitment were the least sensitive measures of impact and indicated a significant response to fire for only 2 of 10 species. We detected measurable effects of the fire for 17 of the 20 species studied. Many of these species had returned to prefire levels within three years, but for nine species the effects were still apparent six years later. Mark-recapture methodology provides an effective way of measuring the impact of fire regimes in forest environments. Long-term monitoring programmes should be established in fire-prone forest environments to contribute toward our understanding of fire, and its effect on avian populations. Such programmes have resource implications and researchers are urged to encourage the participation of the amateur bird banding community to contribute to such projects.

scholarly journals Decadal changes in fire frequencies shift tree communities and functional traits

2020 ◽  
Author(s):  
Adam F. A. Pellegrini ◽  
Tyler Refsland ◽  
Colin Averill ◽  
César Terrer ◽  
A. Carla Staver ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Fire History ◽  
Vegetation Type ◽  
Basal Area ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Tree Communities ◽  
In Fire ◽  
The Impact

Global change has resulted in chronic shifts in fire regimes, increasing fire frequency in some regions and decreasing it in others. Predicting the response of ecosystems to changing fire frequencies is challenging because of the multi-decadal timescales over which fire effects emerge and the variability in environmental conditions, fire types, and plant composition across biomes. Here, we address these challenges using surveys of tree communities across 29 sites that experienced multi-decadal alterations in fire frequencies spanning ecosystems and environmental conditions. Relative to unburned plots, more frequently burned plots had lower tree basal area and stem densities that compounded over multiple decades: average fire frequencies reduced basal area by only 4% after 16 years but 57% after 64 years, relative to unburned plots. Fire frequency had the largest effects on basal area in savanna ecosystems and in sites with strong wet seasons. Analyses of tree functional-trait data across North American sites revealed that frequently burned plots had tree communities dominated by species with low biomass nitrogen and phosphorus content and with more efficient nitrogen acquisition through ectomycorrhizal symbioses (rising from 85% to nearly 100%). Our data elucidate the impact of long-term fire regimes on tree community structure and composition, with the magnitude of change depending on climate, vegetation type, and fire history. The effects of widespread changes in fire regimes underway today will manifest in decades to come and have long-term consequences for carbon storage and nutrient cycling.

scholarly journals A routing-benefited deployment approach combining static and dynamic layouts for underwater optical wireless networks

2021 ◽  
Vol 17 (2) ◽  
pp. 155014772199961
Author(s):  
Zhongwei Shen ◽  
Hongxi Yin ◽  
Yanjun Liang ◽  
Rigele Maao ◽  
Lianyou Jing
Keyword(s):  
Optical Communication ◽  
Loss Rate ◽  
Communication Model ◽  
Optical Wireless ◽  
Wireless Optical Communication ◽  
Area Of Interest ◽  
Virtual Force ◽  
The Impact ◽  
Term Monitoring

A routing-benefited deployment algorithm combining static and dynamic layouts is proposed, and its comprehensive performance evaluation is given in this article. The proposed routing-benefited deployment algorithm is intended to provide a suitable network deployment and subsequent data transmission approach for underwater optical networking and communication. Static nodes are anchored for long-term monitoring, and movable nodes can adjust their depths based on the virtual force and move with the variation of area-of-interest changing. Then, nodes begin to collect data that they can monitor and transmit to sink nodes. Here, the underwater wireless optical communication model is described to actualize the real environment, and the vector-based forwarding protocol is particularly considered to compare the impact of different deployment algorithms on routing. It is shown by simulation experiment results that routing-benefited deployment algorithm outperforms several existing traditional virtual force deployment algorithms in terms of coverage, lifetime, energy consumption balance, packet-loss rate, and time-delay.

Temporal changes in an alligator snapping turtle (Macrochelys temminckii) population

2013 ◽  
Vol 40 (1) ◽  
pp. 77 ◽  
Author(s):  
Mitchell B. East ◽  
J. Daren Riedle ◽  
Day B. Ligon
Keyword(s):  
Management Practices ◽  
Unknown Origin ◽  
Current Status ◽  
Macrochelys Temminckii ◽  
The Status ◽  
Management Recommendations ◽  
The Impact ◽  
Term Monitoring ◽  
Term Data

Context Monitoring populations of long-lived species requires continuous long-term efforts. This is especially applicable for species that have experienced declines range-wide. Aims Our study assessed the current status of a population of wild Macrochelys temminckii and compared the present results to those from a survey conducted nearly a decade ago. Methods Trapping in 2010–2011 was conducted on two creeks within the refuge, during the months of May–July. Capture data were compared with data collected by similar methods in 1997–2001. Key results The population structure of M. temminckii was dominated by juveniles, with few large adults or small juveniles detected and a missing size class was evident. Retrospective analysis of 1997–2001 data revealed that the population was likely to be in decline even then, despite high capture rates. Conclusions The M. temminckii population showed significant declines that indicated that the population had experienced stressors of unknown origin. The status of M. temminckii at the refuge is concerning, given the protection afforded this remnant population. Implications Short-term data from 1997–2001 indicated a healthy M. temminckii population, whereas longer-term data showed that the population has declined, resulting in significant demographic changes. Continued monitoring will be necessary to develop management recommendations and track the impact of implemented management practices. Longer-term monitoring of long-lived vertebrates is required to identify population trends.

scholarly journals Can trophic rewilding reduce the impact of fire in a more flammable world?

2018 ◽  
Vol 373 (1761) ◽  
pp. 20170443 ◽  
Author(s):  
Christopher N. Johnson ◽  
Lynda D. Prior ◽  
Sally Archibald ◽  
Helen M. Poulos ◽  
Andrew M. Barton ◽  
...  
Keyword(s):  
Fire Regimes ◽  
Ground Vegetation ◽  
Litter Layer ◽  
Theme Issue ◽  
Large Herbivores ◽  
Plant Matter ◽  
The World ◽  
Large Animals ◽  
In Fire ◽  
The Impact

Large vertebrates affect fire regimes in several ways: by consuming plant matter that would otherwise accumulate as fuel; by controlling and varying the density of vegetation; and by engineering the soil and litter layer. These processes can regulate the frequency, intensity and extent of fire. The evidence for these effects is strongest in environments with intermediate rainfall, warm temperatures and graminoid-dominated ground vegetation. Probably, extinction of Quaternary megafauna triggered increased biomass burning in many such environments. Recent and continuing declines of large vertebrates are likely to be significant contributors to changes in fire regimes and vegetation that are currently being experienced in many parts of the world. To date, rewilding projects that aim to restore large herbivores have paid little attention to the value of large animals in moderating fire regimes. Rewilding potentially offers a powerful tool for managing the risks of wildfire and its impacts on natural and human values. This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.

scholarly journals Monitoring Selected Species of Mammals in Grand Teton National Park in 2001

2001 ◽  
Vol 25 ◽  
pp. 82-87
Author(s):  
Brian Miller ◽  
Hank Harlow
Keyword(s):  
National Park ◽  
Vegetation Type ◽  
Vegetation Types ◽  
Population Composition ◽  
Grand Teton National Park ◽  
Needed Information ◽  
Mammal Distribution ◽  
The Impact ◽  
Term Monitoring

Our objective is to establish a long-term monitoring project that will assess the abundance and densities of selected species of mammals at sites representing five defined vegetation types found in Grand Teton National Park. The term monitoring implies data collection over multiple years. Taking long term estimations of population composition before, during, and after biotic and abiotic changes provides needed information to assess the impacts of such changes and furnish useful options for management decisions. This standardized monitoring plan will provide information on small and medium-sized mammals that will (1) assess species use of habitat, (2) monitor changes in species composition as a result of environmental change, such as precipitation and temperature, (3) produce predictive models of small and medium-sized mammal distribution based on vegetation type, and (4) analyze the impact of wolf colonization on the mammal (and plant) community.

scholarly journals Reconstructing burnt area during the Holocene: an Iberian case study

2021 ◽  
Author(s):  
Yicheng Shen ◽  
Luke Sweeney ◽  
Mengmeng Liu ◽  
Jose Antonio Lopez Saez ◽  
Sebastián Pérez-Díaz ◽  
...  
Keyword(s):  
Fire Regimes ◽  
Weighted Averaging ◽  
Pollen Data ◽  
Burnt Area ◽  
The Holocene ◽  
Quantitative Estimates ◽  
In Fire ◽  
The Impact ◽  
Pollen Records

Abstract. Charcoal accumulated in lake, bog or other anoxic sediments through time has been used to document the geographical patterns in changes in fire regimes. Such reconstructions are useful to explore the impact of climate and vegetation changes on fire during periods when the human influence was less prevalent than today. However, charcoal records only provide semi-quantitative estimates of change in biomass burning. Here we derive quantitative estimates of burnt area from vegetation data in two stages. First, we relate the modern charcoal abundance to burnt area using a conversion factor derived from a generalized linear model of burnt area probability based on eight environmental predictors. Then, we establish the relationship between fossil pollen assemblages and burnt area using Tolerance-weighted Weighted Averaging Partial Least-Squares with sampling frequency correction (fxTWA-PLS). We test this approach using the Iberian Peninsula as a case study because it is a fire-prone region with abundant pollen and charcoal records covering the Holocene. We derive the vegetation-burnt area relationship using the 29 records that have both modern and fossil charcoal and pollen data, and then reconstruct palaeo-burnt area for the 114 records with Holocene pollen records. The pollen data predict charcoal abundances through time relatively well (R2 = 0.47) and the changes in reconstructed burnt area are synchronous with known climate changes through the Holocene. This new method opens up the possibility of reconstructing changes in fire regimes quantitatively from pollen records, which are far more numerous than charcoal records.

Influence of prescribed burning on fruit production in Proteaceae

2010 ◽  
Vol 16 (1) ◽  
pp. 46 ◽  
Author(s):  
T. D. Penman ◽  
S. H. Penman
Keyword(s):  
Community Structure ◽  
Reproductive Output ◽  
Prescribed Burning ◽  
Fire Regimes ◽  
Fruit Production ◽  
Management Tool ◽  
Fire Intensity ◽  
Term Study ◽  
Long Term Study

Prescribed burning is applied worldwide as a forest management tool. It is broadly accepted that altered fire regimes can directly impact upon community structure and composition, but little is known about the indirect effects of altered fire regimes on the mechanisms that produce community-level changes such as changes to the reproductive output of individual plants, hence populations. We examined the reproductive output of four species of Proteaceae within a long term study site where disturbance histories for the last twenty years have been accurately recorded on 216 plots. Frequent fire was found to increase woody fruit production in Banksia marginata, but had no apparent effect on B. serrata, Hakea eriantha or H. sericea. Results of this study vary from a similar study which examined the effect of wildfires. The differences observed are likely to reflect the differing impacts of fire intensity on these species. Indirect changes in fruit production may result in changes in reproductive success of species which in turn may affect vegetation community structure and faunal habitat.

Changes Over Time

2018 ◽  
pp. 283-305 ◽  
Author(s):  
Peter A. Gell ◽  
Marie-Elodie Perga ◽  
C. Max Finlayson
Keyword(s):  
Data Sets ◽  
Lake Ecosystems ◽  
Wetland Ecosystems ◽  
Sediment Layers ◽  
Time Frames ◽  
Changes Over Time ◽  
The Impact ◽  
Term Monitoring ◽  
Term Data

Freshwater systems are continuously shaped by cyclical and directional forces of change, whether they be natural or anthropogenic. Beyond gradual transitions disturbances can reset their internal dynamics generating an abrupt ecological shift. Long-term data sets of gradual or abrupt change can be accessed by exhuming the physical, chemical, and biological remains archived in the sediment layers within lakes and wetlands. Long-term monitoring programmes offer more detailed evidence, usually over shorter time frames. In combination these records attest to the response of wetlands to climate and the impact of industrialised people. Humans have modified lake ecosystems for millennia and the condition of many wetland ecosystems have changed such that they are now regarded as novel. Long-term records provide targets for wetland restoration and can identify the main drivers of degradation. Identification of the character of modern Ramsar wetlands may be enhanced by reference to records of past state.

Projected population consequences of climate change

2019 ◽  
pp. 147-164 ◽  
Author(s):  
David Iles ◽  
Stéphanie Jenouvrier
Keyword(s):  
Climate Models ◽  
Population Models ◽  
Climate Projections ◽  
Population Modelling ◽  
Population Forecasts ◽  
Long Term Study ◽  
Climate Forecasts ◽  
Key Points ◽  
Avian Populations

To anticipate the future state of avian populations in a changing climate, forecasts must rigorously account for uncertainty in future climate and population processes. This requires fusing IPCC-class climate projections with population models. In this chapter, we review the steps for developing climate-dependent population forecasts, while highlighting key biological considerations and methodological challenges. Throughout, we use examples from a long-term study of emperor penguins (Aptenodytes forsteri) to illustrate key points. We then conduct a literature review to compile a list of studies that have linked IPCC climate models with avian population models. At present, only a handful of studies have fused IPCC climate projections with avian population models, and generalities across systems thus remain elusive. Yet, the increasing availability and sophistication of climate models, coupled with new population modelling methods, hold promise for reducing forecast uncertainties and improving the relevance of population forecasts for policy.

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