2016 ◽  
Vol 62 (6) ◽  
pp. 613-622 ◽  
Author(s):  
Marie-Pierre Rogeau ◽  
Marc-André Parisien ◽  
Mike D. Flannigan

2010 ◽  
Vol 19 (8) ◽  
pp. 1026 ◽  
Author(s):  
Christopher Carcaillet ◽  
Pierre J. H. Richard ◽  
Yves Bergeron ◽  
Bianca Fréchette ◽  
Adam A. Ali

The hypothesis that changes in fire frequency control the long-term dynamics of boreal forests is tested on the basis of paleodata. Sites with different wildfire histories at the regional scale should exhibit different vegetation trajectories. Mean fire intervals and vegetation reconstructions are based respectively on sedimentary charcoal and pollen from two small lakes, one in the Mixedwood boreal forests and the second in the Coniferous boreal forests. The pollen-inferred vegetation exhibits different trajectories of boreal forest dynamics after afforestation, whereas mean fire intervals have no significant or a delayed impact on the pollen data, either in terms of diversity or trajectories. These boreal forests appear resilient to changes in fire regimes, although subtle modifications can be highlighted. Vegetation compositions have converged during the last 1200 years with the decrease in mean fire intervals, owing to an increasing abundance of boreal species at the southern site (Mixedwood), whereas changes are less pronounced at the northern site (Coniferous). Although wildfire is a natural property of boreal ecosystems, this study does not support the hypothesis that changes in mean fire intervals are the key process controlling long-term vegetation transformation. Fluctuations in mean fire intervals alone do not explain the historical and current distribution of vegetation, but they may have accelerated the climatic process of borealisation, likely resulting from orbital forcing.


2011 ◽  
Vol 20 (8) ◽  
pp. 974 ◽  
Author(s):  
Graeme Armstrong ◽  
Sarah Legge

Triodia spp. have been described as behaving functionally as a shrub because above ground biomass accumulates slowly over time culminating as the dominant vegetation layer. When combined with high flammability, little seed dormancy and conflicting evidence for fire induced seed germination, obligate seeding species may be more vulnerable to short fire intervals than resprouting species. This study investigated the post-fire regeneration response of the obligate seeder Triodia sp. nov. (aff. T. schinzii Henrard) in the fire prone Kimberley, Western Australia. Adult plants were destroyed by fire in experimental plots to assess the degree of regeneration from either resprouting or germination from seed due to fire. To control for the removal of adults, without fire, plants were pulled out by hand in replicate plots. Germination of Triodia sp. nov. seed from the soil seed bank was strongly induced by fire. Establishment and survival of seedlings through the first dry season was high with a small proportion of individuals flowering at this time. It is concluded that Triodia sp. nov. is resilient to the short fire intervals experienced in the Kimberley where it is a successful localised species.


2006 ◽  
Vol 15 (3) ◽  
pp. 439 ◽  
Author(s):  
Peter Z. Fulé ◽  
Thomas A. Heinlein ◽  
W. Wallace Covington

Fire scars and other paleoecological methods are imperfect proxies for detecting past patterns of fire events. However, calculations of long fire rotations in Grand Canyon ponderosa pine forests by Baker are not convincing in methodology or assumptions compared with fire-scar evidence of frequent surface fires. Patches of severe disturbance are a possible hypothesis to explain the relatively short age structure at the park, where ~12% fewer trees were older than 300 years compared with another unharvested northern Arizona site. However, mapped patterns of old trees as well as the evidence for frequent surface fire from fire scars, charcoal deposition studies, and evolutionary history are more consistent with the dominance of surface fire prior to c. 1880. The most relevant available evidence of fire recurrence at a given point, mean point fire intervals, had median values <16 years at all five study sites, close to filtered composite fire interval statistics (~6–10 years), but much lower than Baker’s calculated fire rotation values (55–110 years). The composite fire interval is not a uniquely important statistic or a numerical guideline for management, but one of many lines of evidence underscoring the ecological role of frequent surface fire in ponderosa pine forests.


1998 ◽  
Vol 46 (2) ◽  
pp. 241 ◽  
Author(s):  
Jennifer E. Taylor ◽  
Vaughan Monamy ◽  
Barry J. Fox

Xanthorrhoea fulva (A.Lee) Bedford is a dominant plant of wet heath at Myall Lakes National Park, New South Wales, Australia. As for many other members of the genus, fire is the main stimulus for flowering of X. fulva. The stimulus to flowering provided by fire and by crown removal (clipping) of X. fulva was compared in two different seasons and for two different between-fire intervals. The percentage of X. fulva crowns flowering was greater following: (i) summer disturbance when compared with winter disturbance; (ii) short between-fire intervals (3.75 or 5.25 years) when compared with long between-fire intervals (9.3 or 16.9 years); and (iii) burning when compared with clipping. This demonstrates that the stimulus to floral induction in X. fulva is a combination of a seasonal component and crown removal, a component related to the interval since the last fire, and perhaps some other factor(s) not tested for in this study. This variation in flowering response of X. fulva shows the importance of considering immediate and historic characteristics of fire and other disturbances when management decisions are being made.


2005 ◽  
Vol 35 (9) ◽  
pp. 2073-2081 ◽  
Author(s):  
Andrea H Lloyd ◽  
Alexis E Wilson ◽  
Christopher L Fastie ◽  
R Matthew Landis

Black spruce (Picea mariana (Mill.) BSP) is the dominant species in interior Alaska but it is largely absent from the arctic tree line. To evaluate the importance of climate and fire as controls over the species distribution, we reconstructed stand history at three sites near its northern limit in Alaska, where it grows with white spruce (Picea glauca (Moench) Voss). We developed a matrix model to explore black spruce population dynamics and response to varying fire intervals. All sites burned in the early 1900s. High recruitment of black spruce occurred for <30 years following the fire, but most current black spruce recruitment is clonal and seed viability is low. White spruce recruitment has been consistently high since the fire, and the majority of seedlings in the stands are white spruce. Despite low recruitment, the matrix model suggests that black spruce populations are nearly stable, largely because of low adult mortality rates. Although black spruce recruitment is stimulated by fire, the model indicates that fire intervals <350 years would destabilize the population, primarily because of slow growth and low seed production. Population dynamics of black spruce at its northern limit in Alaska thus appear to reflect an interaction between fire, which determines the temporal pattern of tree recruitment, and climate, which limits tree growth and, presumably, viable seed production.


2005 ◽  
Vol 35 (11) ◽  
pp. 2719-2726 ◽  
Author(s):  
Rune Groven ◽  
Mats Niklasson

Fire-scarred wood samples from 50 stumps, snags, and living trees of Scots pine (Pinus sylvestris L.) were dendrochronologically cross-dated to describe an 800 year long fire history of Eldferdalen Nature Reserve (~6 ha) and its surroundings (~4000 ha) in southeastern Norway. In the western part of the study area, we recorded 55 different fires within a 200 ha area around the reserve between 1511 and 1759 and a mean fire interval in single samples of 24.6 years. The composite mean fire interval for the nature reserve was 10.5 years. Fire intervals were longer in the eastern part of the study area, with a single sample mean fire interval of 49.1 years. Only three fires were detected after 1759, the last one in 1822. Based on historical accounts, we assume that the high number of fires and short fire intervals were influenced by deliberate ignition for agricultural purposes, most likely burning to improve the conditions for cattle grazing and slash-and-burn cultivation. We suggest that the cessation of fires was influenced by the increased value of timber and mining activity, thereby leading to increased interest in conservation of the timber resources.


1989 ◽  
Vol 19 (11) ◽  
pp. 1451-1457 ◽  
Author(s):  
Mark A. Finney ◽  
Robert E. Martin

Fire occurrence data between the 12th and 20th centuries were obtained from analysis of fire scars on coast redwood (Sequoiasempervirens (D. Don.) Endl.) and bishop pine (Pinusmuricata D. Don.). Mean fire intervals were calculated for settlement and presettlement periods from fire scar samples individually (point data) and from composites of samples aggregated within three approximately 200-ha study areas. Mean fire intervals from point data (20.5 to 29.0 years) were more than three times greater than mean intervals from composite data (6.1 to 9.3 years). Mean fire intervals derived from point data compared well with values previously reported, although substantial bias ascribed to point data suggests that these values for mean fire intervals in redwood forest communities are too large. A period of significantly longer fire intervals during the 17th century was suggested by analysis of fire intervals by century and using a moving average.


2017 ◽  
Vol 65 (4) ◽  
pp. 339 ◽  
Author(s):  
J. M. Harvey ◽  
A. J. M. Hopkins ◽  
M. A. Langley ◽  
C. R. Gosper ◽  
M. R. Williams ◽  
...  

Identifying appropriate fire-return times is critical for management of temperate southern Australia’s fire-prone shrublands and woodlands. The time to first flowering and peak flowering are useful attributes for understanding how species and vegetation will respond to different fire intervals. Using a plant fire-response trait framework, we investigate patterns of reproduction in south-western Australian kwongan and woodland after prescribed fires with a 30-year longitudinal study, with the aim of identifying appropriate fire intervals. Modelling of post-fire flowering responses of species and aggregating responses into plant functional types showed substantial differences in the time after fire to first and peak flowering. Tests of hypotheses of flowering patterns after fire with different fire-response traits showed that (1) resprouters flower sooner than recruits of non-resprouters, (2) serotinous non-resprouters reach first and peak flowering later than do non-resprouters with soil-stored seed, (3) species in taller strata reach first and peak flowering later than those in lower strata and (4) geophytes flower earlier than other resprouters that lose their aboveground biomass in fire. The most fire interval-sensitive non-resprouting serotinous species take 15–20 years in kwongan to reach peak flowering and in Allocasuarina woodland 25–30 years, providing a working hypothesis for minimum fire intervals in the plant communities under investigation. Our study illustrates the value of long-term ecological studies for informing biodiversity management.


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