Landscape Eragmentation and Forest Composition Effects on Grouse Breeding Success in Boreal Forests

Ecology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1985 ◽  
Author(s):  
Sami Kurki ◽  
Ari Nikula ◽  
Pekka Helle ◽  
Harto Linden
Keyword(s):  
Breeding Success ◽  
Boreal Forests ◽  
Forest Composition ◽  
Composition Effects

LANDSCAPE FRAGMENTATION AND FOREST COMPOSITION EFFECTS ON GROUSE BREEDING SUCCESS IN BOREAL FORESTS

Ecology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1985-1997 ◽  
Author(s):  
Sami Kurki ◽  
Ari Nikula ◽  
Pekka Helle ◽  
Harto Lindén
Keyword(s):  
Breeding Success ◽  
Boreal Forests ◽  
Landscape Fragmentation ◽  
Forest Composition ◽  
Composition Effects

scholarly journals High latitude cooling associated with landscape changes from North American boreal forest fires

2012 ◽  
Vol 9 (9) ◽  
pp. 12087-12136 ◽  
Author(s):  
B. M. Rogers ◽  
J. T. Randerson ◽  
G. B. Bonan
Keyword(s):  
Boreal Forest ◽  
High Latitude ◽  
Forest Fires ◽  
Boreal Forests ◽  
Regional Climate ◽  
Forest Composition ◽  
Energy Budgets ◽  
Surface Cooling ◽  
Functional Variation ◽  
Greenhouse Gasses

Abstract. Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated the changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would result in surface cooling of 0.23 ± 0.09 °C and 0.43 ± 0.12 °C for winter–spring and February–April time periods, respectively. This could provide a negative feedback to high-latitude terrestrial warming during winter on the order of 4–6% for a doubling, and 14–23% for a quadrupling, of burn area. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.

scholarly journals High-latitude cooling associated with landscape changes from North American boreal forest fires

2013 ◽  
Vol 10 (2) ◽  
pp. 699-718 ◽  
Author(s):  
B. M. Rogers ◽  
J. T. Randerson ◽  
G. B. Bonan
Keyword(s):  
North America ◽  
Boreal Forest ◽  
High Latitude ◽  
Forest Fires ◽  
Boreal Forests ◽  
Regional Climate ◽  
Forest Composition ◽  
Energy Budgets ◽  
Functional Variation ◽  
Greenhouse Gasses

Abstract. Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would cool the surface by 0.23 ± 0.09 °C across boreal North America during winter and spring months (December through May). This could provide a negative feedback to winter warming on the order of 3–5% for a doubling, and 14–23% for a quadrupling, of burn area. Maximum cooling occurs in the areas of greatest burning, and between February and April when albedo changes are largest and solar insolation is moderate. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.

Interaction between peatland moisture and plant functional types drives fire dynamics in forested peatlands in central-western Siberia

2021 ◽  
Author(s):  
Angelica Feurdean ◽  
Andrei-Cosmin Diaconu ◽  
Geanina Butiseaca ◽  
Mariusz Galka ◽  
Simon M. Hutchinson ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Western Siberia ◽  
Fire Regime ◽  
Fire Regimes ◽  
Forest Composition ◽  
Vegetation Composition ◽  
Picea Obovata ◽  
Peatland Hydrology ◽  
In Fire

<p>Boreal forests are among the ecosystems most significantly impacted by wildfires as a consequence of climate warming. A large proportion of the global boreal forest area is located in Siberia, however, its vast extent and restricted access limit datasets recording changes in wildfire activity, especially from a longer-term perspective. Such long-term records of wildfire activity are vital to understanding how fire regimes vary with changes in climate, vegetation composition and human-vegetation interaction, as well as the impacts of wildfires on boreal forests.</p><p>Here, we explore how patterns in fire regime (biomass burned, fire frequency, fire type) have changed over the Holocene. We focus on the relationship between fire regime, forest density and the fire-related traits of the main tree species, and peatland hydrology. We used charcoal-morphologies based reconstructions of fire regimes, along with pollen-based assessments of vegetation composition and testate amoebae-based hydro-climate reconstructions in Pinus-Betula dominated peatlands from central-western Siberia, Tomsk Oblast, Russia.</p><p>The occurrence of more severe fires (i.e., higher biomass burning per fire episode and abundant woody morphotypes) were recorded between 7500 and 5000 cal yr BP. Higher temperatures during that time, likely enhanced peatland dryness and fuel flammability creating conditions conducive to peat and forest fires. Drier peatland conditions also affected forest composition and density by favouring the expansion of a mix of light taiga and fire resisters (e.g., Pinus sylvestris, P. sibirica, Larix) with denser taiga and fire avoiders (Picea obovata and Abies sibirica) on the peatland. A shift to the lowest biomass burning and fire types affecting mostly litter and understorey vegetation, was registered between 4000 and 1500 cal yr BP. Temporally, it coincides with an increase in peatland surface moisture and a change in forest composition characterised by a decline in fire resisters, while fire avoiders remained abundant. An almost synchronous intensification in fires frequency and severity from ca. 2000 cal yr BP to the present at all sites, was concurrent with the rise to dominance of fire-invader species (Betula), as well as a more abundant biomass in the understory layer (shrubs, herbs, ferns, moss), while fire resisters and avoiders declined substantially. We found that Picea obovata to be highly vulnerable tree taxa to frequent, severe fires.</p><p>This long-term perspective demonstratesthat peatland hydrology is connected to, and feedbacks on peatland and forest composition and fuel dryness and ultimately fire regime. It also shows that more frequent fires of higher severity can lead to compositional or structural changes of forests, if trees cannot reach reproductive ages prior to the next burning events. Future predicted increases in temperatures are likely to enhance peatland drying, with cascading effects on forest and peat plant composition, subsequently exacerbating wildfire activity. This study thus contributes to an understanding of disturbance regimes in boreal forests and considers their potential to adapt to new climate conditions and fire regimes.</p><p> </p>

Road network density correlated with increased lightning fire incidence in the Canadian western boreal forest

2009 ◽  
Vol 18 (8) ◽  
pp. 970 ◽  
Author(s):  
M. Cecilia Arienti ◽  
Steven G. Cumming ◽  
Meg A. Krawchuk ◽  
Stan Boutin
Keyword(s):  
Boreal Forests ◽  
Negative Binomial ◽  
Fire Regime ◽  
Positive Association ◽  
Fire Frequency ◽  
Forest Composition ◽  
Road Density ◽  
Linear Features ◽  
Linear Feature ◽  
Lightning Fire

This paper quantifies the influence of anthropogenic linear disturbances on fire ignition frequency in the boreal forests of western Canada. Specifically, we tested if linear features increase the frequency of lightning fires, and whether this relationship is affected by spatial resolution. We considered fires that ignited between 1995 and 2002 within a ~67 000 km2 region of boreal mixed-wood forest in north-eastern Alberta where linear features are highly abundant and spatially heterogeneous. We constructed Poisson, Negative Binomial and Zero-Inflated Poisson models at two spatial resolutions (~10 000 and ~2400 ha), including covariates for linear feature densities, forest composition, weather–lightning indices and geography. We found a positive association between lightning fire frequency and road density; this association was consistent at both spatial resolutions. We suggest this occurs owing to increased availability of flammable fine fuels near roads. The effect was attributable neither to increased detectability of fires proximal to roads by human observers, nor to increased lightning strikes due to metallic infrastructure alongside roads or the topographic characteristics of road location. Our results suggest that, in the face of projected road developments in the region, the potential exists for important changes to the regional fire regime. Further research should elucidate the precise mechanisms in order to develop methods for mitigation.

What is the natural rhythm of temperate and boreal forest disturbances in the absence of human management?

2020 ◽  
Author(s):  
Thomas Pugh ◽  
Cornelius Senf ◽  
Rupert Seidl
Keyword(s):  
Boreal Forest ◽  
Protected Areas ◽  
Northern Hemisphere ◽  
Boreal Forests ◽  
Forest Composition ◽  
Natural State ◽  
Continental Scale ◽  
Disturbance Regimes ◽  
Disturbance Frequency ◽  
Human Management

<p>The vast majority of temperate and much of the boreal forest have been completely transformed by human activities, changing forest composition and disturbance regimes. Whilst our capability to observe this transformed state has improved dramatically in recent years, we have precious little information on the state of these forests in the absence of management. To what extent do our forests currently suffer from a surplus or a deficit of disturbance relative to their natural state? What are the implications of this for carbon turnover? Using a novel fusion of satellite observations of stand-replacing disturbances in 80 protected areas, statistical analysis and dynamic vegetation modelling, we generated wall-to-wall estimates of disturbance frequency across northern hemisphere temperate and boreal forests. Analysis of disturbance events in the protected areas revealed that the probability of disturbances from agents including fire, wind-throw and bark beetles was related to community mean functional traits and climate. We used the LPJ-GUESS dynamic vegetation model, which explicitly simulates plant functional types covering different successional stages, to simulate forest functional composition in the absence of human management. We interactively coupled this simulation to a new disturbance probability module to generate estimates of natural disturbance probability across all northern-hemisphere temperate and boreal forests. Disturbance frequency ranged from ca. one stand-replacing event per hundred years in parts of the boreal to less than one per thousand years in broadleaved temperate forests. In many regions the unmanaged disturbance frequencies differed dramatically from those observed in reality over the last two decades, with both disturbance surplus and deficits being recorded. In addition to providing the first quantitative continental-scale assessment of human impact on forest disturbance regimes, our results also provide a lightweight modelling approach for the inclusion of natural disturbances in large-scale vegetation models. They thus facilitate simulation of forest structure, a crucial driver of ecosystem function, from carbon uptake to biodiversity.</p>

scholarly journals How Initial Forest Cover, Site Characteristics and Fire Severity Drive the Dynamics of the Southern Boreal Forest

2020 ◽  
Vol 12 (23) ◽  
pp. 3957
Author(s):  
Victor Danneyrolles ◽  
Osvaldo Valeria ◽  
Ibrahim Djerboua ◽  
Sylvie Gauthier ◽  
Yves Bergeron
Keyword(s):  
Boreal Forest ◽  
Forest Fires ◽  
Forest Dynamics ◽  
Boreal Forests ◽  
Forest Cover ◽  
Fire Severity ◽  
Fire Frequency ◽  
Aerial Photographs ◽  
Forest Composition ◽  
Site Characteristics

Forest fires are a key driver of boreal landscape dynamics and are expected to increase with climate change in the coming decades. A profound understanding of the effects of fire upon boreal forest dynamics is thus critically needed for our ability to manage these ecosystems and conserve their services. In the present study, we investigate the long-term post-fire forest dynamics in the southern boreal forests of western Quebec using historical aerial photographs from the 1930s, alongside with modern aerial photographs from the 1990s. We quantify the changes in forest cover classes (i.e., conifers, mixed and broadleaved) for 16 study sites that were burned between 1940 and 1970. We then analyzed how interactions between pre-fire forest composition, site characteristics and a fire severity weather index (FSWI) affected the probability of changes in forest cover. In the 1930s, half of the cover of sampled sites were coniferous while the other half were broadleaved or mixed. Between the 1930s and the 1990s, 41% of the areas maintained their initial cover while 59% changed. The lowest probability of changes was found with initial coniferous cover and well drained till deposits. Moreover, an important proportion of 1930s broadleaved/mixed cover transitioned to conifers in the 1990s, which was mainly associated with high FSWI and well-drained deposits. Overall, our results highlight a relatively high resistance and resilience of southern boreal coniferous forests to fire, which suggest that future increase in fire frequency may not necessarily result in a drastic loss of conifers.

Climate change and breeding success: decline of the capercaillie in Scotland

2001 ◽  
Vol 70 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Robert Moss ◽  
James Oswald ◽  
David Baines
Keyword(s):  
Climate Change ◽  
Breeding Success

Chemical composition effects in the thin films of the colossal magnetoresistive perovskite manganates grown by MOCVD

1999 ◽  
Vol 09 (PR8) ◽  
pp. Pr8-659-Pr8-666 ◽  
Author(s):  
O. Yu. Gorbenko ◽  
I. E. Graboy ◽  
A. A. Bosak ◽  
V. A. Amelichev ◽  
A. Yu. Ganin ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Colossal Magnetoresistive ◽  
Composition Effects
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