Fuel flammability and fire responses of juvenile canopy species in a temperate rainforest ecosystem

2015 ◽  
Vol 24 (3) ◽  
pp. 349 ◽  
Author(s):  
Heidi C. Zimmer ◽  
Tony D. Auld ◽  
Lesley Hughes ◽  
Catherine A. Offord ◽  
Patrick J. Baker
Keyword(s):  
Fire Severity ◽  
Soil Surface ◽  
Controlled Environment ◽  
Temperate Rainforest ◽  
Canopy Tree ◽  
Litter Flammability ◽  
Lower Temperature ◽  
Fuel Moisture Content ◽  
Warm Temperate ◽  
Fire Ignition

Historically, rainforests have been considered vulnerable to fire. Recent research, however, has shown that many rainforest species can survive fire by resisting burning and by resprouting and seeding post-fire. We investigated the response of a warm temperate rainforest community to fire by burning juveniles of the dominant canopy tree species (Doryphora sassafras, Syzygium smithii and Wollemia nobilis) and examining litter flammability in a controlled environment. The three species resprouted after the experimental burn, predominantly from buds on the stem that were below the soil surface. Higher fire temperatures resulted in reduced overall plant height and resprouting from buds lower on the stem. Increasing proportions of W. nobilis litter generated fires with higher intensities and fuel consumption compared with rainforest angiosperm litter. Moreover, fuel moisture content decreased with increasing W. nobilis litter proportions. Higher litter flammability may result in increased likelihood of fire ignition and fire severity near W. nobilis trees, which would negatively impact the juveniles of all three rainforest species. Alternatively, after lower-temperature fires (e.g. in rainforest angiosperm litter), W. nobilis may have an advantage over the other species because of faster-growing resprouts occurring higher on the stem.

The recovery of rainforest overstorey following logging 2. Warm temperate rainforest

1987 ◽  
Vol 22 (3-4) ◽  
pp. 267-281 ◽  
Author(s):  
Ross Horne ◽  
John Gwalter
Keyword(s):  
Temperate Rainforest ◽  
Warm Temperate

Residual Large Trees Influence Short-term Succession Following a Volcanic Eruption in a Valdivian Temperate Rainforest

2021 ◽  
Author(s):  
Lisa Hintz ◽  
Dylan Fischer ◽  
Nina Ferrari ◽  
Charlie M.S. Crisafulli
Keyword(s):  
Soil Surface ◽  
Bare Soil ◽  
Understory Vegetation ◽  
Percent Cover ◽  
Vegetative Cover ◽  
Vegetation Response ◽  
Temperate Rainforest ◽  
Large Trees ◽  
Close Proximity ◽  
Disturbed Forest

Abstract Airborne volcanic ejecta (tephra) can strongly influence forest ecosystems through initial disturbance processes and subsequent ecological response. Within a tephra-disturbed forest, large trees may promote plant growth and create favorable sites for colonization. Three primary ways trees can influence post-eruption vegetation response include: 1) amelioration of volcanic substrates, 2) as source propagules from the tree or from associated epiphytes, and 3) by sheltering understory vegetation, thereby increasing rate of recovery near tree bases. Here, we evaluate Valdivian temperate rainforest understory vegetation response and soil characteristics in close proximity to large trees that survived the 2015 eruption of Calbuco Volcano. Understory vegetative cover was higher near the base of trees for mosses, many epiphytes, and some herbaceous, shrub, and trees species. However, significant interactions with year of measurement, and individualistic responses by many species made generalizations more difficult. Small shrubs and trees in particular demonstrated patterns of recovery that were frequently independent of distance. In some cases, percent cover of colonizing vegetation actually increased far from trees by 2019. The soil surface was similarly variable where bare soil cover was associated with locations proximal to tree bases, but material shed from living and dead standing vegetation increased wood and litter abundances on the soil surface away from the base of trees. Soils near trees had lower pH, elevated organic matter, and higher nitrogen and carbon. Our results support the assertion that in this temperate rainforest ecosystem, large trees can modify edaphic conditions and provide important early refugia for vegetative regrowth following a tephra fall event. Nevertheless, complex interactions through time with species and growth form, suggest the influence of large trees on plant establishment and growth with close proximity tree boles is more complex than a simple facilitative model might suggest.

scholarly journals Grass Canopy Architecture Influences Temperature Exposure at Soil Surface

Fire ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 35 ◽  
Author(s):  
Xiulin Gao ◽  
Dylan Schwilk
Keyword(s):  
Fire Regime ◽  
Fire Behavior ◽  
Soil Surface ◽  
Grass Species ◽  
Canopy Architecture ◽  
Height Ratio ◽  
Biomass Density ◽  
Litter Flammability ◽  
Temperature Exposure ◽  
Density And Biomass

There is increasing recognition that plant traits contribute to variations in fire behavior and fire regime. Diversity across species in litter flammability and canopy flammability has been documented in many woody plants. Grasses, however, are often considered homogeneous fuels in which any flammability differences across species are attributable to biomass differences alone and therefore are of less ecological interest, because biomass is hugely plastic. We examined the effect of grass canopy architecture on flammability across eight grass species in short grass steppe of New Mexico and Texas. To characterize grass canopy architecture, we measured biomass density and “biomass-height ratio” (the ratio of canopy biomass above 10 cm to that of biomass below 10 cm). Indoor flammability experiments were performed on air-dried individual plants. As expected, plant biomass influenced all flammability measures. However, biomass-height ratio had additional negative effect on temperature exposure at soil surface (accumulation of mean temperature >100 °C) in well-cured grasses, which is an important fire behavior metric predicting soil heating and meristem survival. This canopy architecture effect, however, needs further investigation to be isolated from biomass density due to correlation of these two traits. This result demonstrates the potential for species-specific variation in architecture to influence local fire effects in grasses.

Contrasting Responses of Morphologically Similar Wheat Cultivars to Temperatures Appropriate to Warm Temperature Climates With Hot Summers: a Study in Controlled Environment

1977 ◽  
Vol 4 (6) ◽  
pp. 877 ◽  
Author(s):  
AK Bagga ◽  
HM Rawson
Keyword(s):  
Temperature Stability ◽  
Kernel Weight ◽  
Controlled Environment ◽  
Wheat Cultivars ◽  
Warm Temperature ◽  
Temperature Regimes ◽  
Wide Range ◽  
Phase Temperature ◽  
Warm Temperate ◽  
Plant Basis

This study attempted to determine if and why there are differences among three cultivars of wheat in their responses to temperature. The three semidwarf cultivars examined, Kalyansona, Condor and Janak, are currently used commercially. Temperature regimes chosen matched the range to which plants in warm temperate climates with hot summers would be exposed at different stages of development. Plants were grown in a phytotron in sunlit cabinets. Responses to temperature were different among the cultivars. Kalyansona was relatively un- responsive to temperatures during the floret phase, being little affected in the sizes of upper leaves, in floret production and grain set, in overall plant growth or in grain yield. The sole character to respond to temperature in this cultivar was kernel weight, which declined with increasing grain phase temperature. In contrast, Condor demonstrated marked plasticity during the floret phase in all plant characters measured. Its plasticity was such that, at the lower temperatures, it outyielded Kalyansona by a substantial margin while at the higher temperatures its yield was relatively poor. On a plant basis, Janak performed similarly to Condor. Rates of photosynthesis were relatively unaffected by temperature in any cultivar. This wide range of response among three superficially similar cultivars has promising implications for the tailoring of cultivars for different temperature zones. The importance of different plant characters to temperature stability is considered in the discussion.

Numerical Investigation of Thermal Characteristics in a Solar Chimney Project

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Hongtao Xu ◽  
Fariborz Karimi ◽  
Mo Yang
Keyword(s):  
Temperature Field ◽  
Numerical Investigation ◽  
Thermal Characteristics ◽  
Soil Surface ◽  
Solar Chimney ◽  
Simulation Methodology ◽  
Plant Cultivation ◽  
Soil Surface Temperature ◽  
Lower Temperature ◽  
Heat Amount

In order to create interior multiclimate zones suitable for plant cultivation in a solar chimney project proposed for the World Horticultural Exposition 2016 in China, the numerical investigation is performed to a solar chimney with 2 km radius and 1 km height. The simulation methodology is validated by experimental data. The impacts of inlet height and radius to interior thermal characteristics are evaluated. It is found that the temperature field is much similar when the inlet height decreases from 3.8 m to 0.5 m. With further decrease of the inlet height to 0.2 m, its impact to temperature field is significant. The temperature field is similar though the radius of solar chimney decreases from 2.0 km to 1.725 km. Further decrease to 1.13 km results in much lower temperature field as less radiate heat is obtained. The procedure of soil surface temperature calculation is also proposed to obtain the supplementary heat amount maintaining the required temperature for plant cultivation.

Models for predicting fire ignition probability in graminoids from boreo–temperate moorland ecosystems

2016 ◽  
Vol 25 (6) ◽  
pp. 679 ◽  
Author(s):  
Victor M. Santana ◽  
Rob H. Marrs
Keyword(s):  
Late Summer ◽  
Early Spring ◽  
Fuel Load ◽  
Probability Models ◽  
Rating Systems ◽  
Seasonal Differences ◽  
Ignition Probability ◽  
Critical Moisture ◽  
Fuel Moisture Content ◽  
Fire Ignition

An increase in both the frequency and severity of wildfires in boreo–temperate ecosystems is predicted. Therefore, to develop efficient fire rating systems, the relationship between the fuel moisture content (FMC) of vegetation and ignition thresholds needs to be determined. We developed fire ignition probability models for three graminoid species collected in central England, but common in boreo–temperate ecosystems (Eriophorum angustifolium, E. vaginatum and Molinia caerulea). Specifically, we assessed through laboratory experiments (1) seasonal differences between early spring and late summer in fuel traits such as height, fuel load, fuel bulk density and dead fuel load proportion, and (2) the role of these fuel traits, environmental conditions and dead FMC in determining the probability of ignition. There were seasonal differences in fuel traits among species, with an increase in dead fuel load proportion after winter. The dead FMC was the only variable determining initial sustained ignitions. However, the seasonal differences in dead fuel were not sufficient to affect the FMC threshold at which graminoids start to ignite. Graminoids begin to ignite at high levels of dead FMC, and there are differences between species (from 36.1% to 48.1%). This work assists in improving fire ignition predictions in graminoid-dominated ecosystems by providing warnings based on critical moisture thresholds.

Establishment and survival of pasture species from seeds sown on the soil surface

1971 ◽  
Vol 22 (1) ◽  
pp. 61 ◽  
Author(s):  
PM Dowling ◽  
RJ Clements ◽  
JR McWilliam
Keyword(s):  
Surface Roughness ◽  
Arable Land ◽  
Soil Surface ◽  
Prior Treatment ◽  
Controlled Environment ◽  
Vegetative Cover ◽  
Factors Influencing ◽  
Germinating Seeds ◽  
Aerial Seeding ◽  
Survival Of Seedlings

Some of the factors influencing the establishment and survival of temperate pasture species when sown on the soil surface were investigated. The following were the main findings from experiments conducted in the field and in a controlled environment. (1) Both the establishment and survival of seedlings sown by broadcasting on to non-arable land can be significantly improved by a prior treatment of the site with herbicide to reduce competition from existing vegetation. (2) Providing protection for seeds by retaining dead vegetative cover, or by creating some form of surface roughness, improves establishment as it reduces desiccation and provides a more favourable moisture environment in the vicinity of the seed. (3) Uptake of water by seeds resting on the soil surface is enhanced by absorbent lime or bentonite coatings, and increased germination results. (4) Failure of radicles to penetrate the soil following germination is an important factor limiting the establishment of legumes on exposed sites, and any restraint on the movement of germinating seeds under these conditions improves the penetration of the radicle. (5) Variation between species in their ability to establish on the surface suggests that the choice of more suitable species, and selection to improve their adaptation in this respect, could also contribute a great deal to the efficiency of aerial seeding.

Conversion of fuel moisture content values to ignition potential for integrated fire danger assessment

2004 ◽  
Vol 34 (11) ◽  
pp. 2284-2293 ◽  
Author(s):  
Emilio Chuvieco ◽  
Inmaculada Aguado ◽  
Alexandros P Dimitrakopoulos
Keyword(s):  
Moisture Content ◽  
Fire Danger ◽  
Assessment System ◽  
Fuel Moisture ◽  
Fire Propagation ◽  
Web Mapping ◽  
Danger Assessment ◽  
Fuel Moisture Content ◽  
In Fire ◽  
Fire Ignition

Fuel moisture content (FMC) estimation is a critical part of any fire danger rating system, since fuel water status is determinant in fire ignition and fire propagation. However, FMC alone does not provide a comprehensive assessment of fire danger, since other factors related to fire ignition (lightning, human factors) or propagation (wind, slope) also need to be taken into account. The problem in integrating all these factors is finding a common scale of danger rating that will make it possible to derive synthetic indices. This paper reviews the importance of FMC in fire ignition and fire propagation, as well as the most common methods of estimating FMC values. A simple method to convert FMC values to danger ratings is proposed, based on computing ignition potential from thresholds of moisture of extinction adapted to each fuel. The method has been tested for the Madrid region (central Spain), where a fire danger assessment system has been built. All the variables related to fire danger were integrated into a dedicated geographic information system and information provided to fire managers through a web mapping server.

Flood Resistance of Tristaniopsis laurina and Acmena smithii From Riparian Warm Temperate Rain-Forest in Victoria

1990 ◽  
Vol 38 (4) ◽  
pp. 371 ◽  
Author(s):  
DR Melick
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Tree Species ◽  
Rain Forest ◽  
Ecological Status ◽  
Flood Damage ◽  
Temperate Rainforest ◽  
Flood Resistance ◽  
Temperate Rain Forest ◽  
Warm Temperate

The responses of seedlings of Tristaniopsis laurina and Acmena smithii, two important tree species in riparian warm temperate rainforest communities in Victoria, are investigated in relation to flood disturbances. Freshly germinated A. smithii seedlings had died within 5 weeks of complete waterlogging in the greenhouse, and although the young T. laurina seedlings survived waterlogging for 14 weeks, their growth rate was curtailed. Nine-month-old seedlings of both species were found to be relatively tolerant to waterlogging, forming aerenchymatous surface roots after 40 days of flooding. Neither species suffered leaf abscission or demonstrated any other signs of water stress commonly associated with flood intolerant species. In experiments to determine the resilience of these species to physical flood damage, both species also demonstrated a capacity to regenerate vegetatively following the removal of above ground parts in young seedlings. The heartwood of T. laurina was found to be more decay resistant than that of other species in the field including that of A. smithii. The significance of these results are discussed in relation to other factors examined in earlier papers adding to the understanding of the ecological status of these species within the riparian rainforest communities.

Survival of Pseudomonas syringae pv. pisi in soil and on pea trash and their importance as a source of inoculum for a following field pea crop

1997 ◽  
Vol 37 (3) ◽  
pp. 369 ◽  
Author(s):  
G. J. Hollaway ◽  
T. W. Bretag
Keyword(s):  
Grain Yield ◽  
Pseudomonas Syringae ◽  
Field Trial ◽  
Bacterial Blight ◽  
Soil Surface ◽  
Field Studies ◽  
Field Pea ◽  
Crop Rotations ◽  
Controlled Environment ◽  
Field Peas

Summary. The importance of soil and field pea trash as sources of Pseudomonas syringae pv. pisi for infection of field pea was investigated both in a controlled environment and in the field. Studies of the survival of P. syringae pv. pisi in soil using autoclaved and non-autoclaved soil found that P. syringae pv. pisi is unlikely to survive in soil from one season to the next suggesting that soil is an unlikely source of inoculum in the field. However, Pseudomonas syringae pv. pisiwas able to survive on buried pea trash for at least 29 weeks and on pea trash positioned on the soil surface for at least 78 weeks. In a field trial, the presence of pea trash naturally infected with P. syringae pv. pisi caused significant bacterial blight and reduced grain yield of a field pea crop by 25%. Therefore, pea trash is a potent source of inoculum and crop rotations which include 2 seasons free of field peas should be considered as part of a strategy to control bacterial blight.

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