scholarly journals Fuel load, stand structure, and understory species composition following prescribed fire in an old-growth coast redwood (Sequoia sempervirens) forest

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
David Cowman ◽  
Will Russell
Keyword(s):  
Species Composition ◽  
Prescribed Burning ◽  
Sequoia Sempervirens ◽  
Anthropogenic Sources ◽  
Fuel Load ◽  
Old Growth ◽  
Understory Species ◽  
Coast Redwood ◽  
Understory Species Composition ◽  
Redwood Forests

Abstract Background With the prevalence of catastrophic wildfire increasing in response to widespread fire suppression and climate change, land managers have sought methods to increase the resiliency of landscapes to fire. The application of prescribed burning in ecosystems adapted to fire can reduce fuel load and fire potential while minimizing impacts to the ecosystem as a whole. Coast redwood forests have historically experienced fire from both natural and anthropogenic sources, and are likely to respond favorably to its reintroduction. Results Random sampling was conducted in three burned sites and in three unburned sites, in an old-growth coast redwood (Sequoia sempervirens [D. Don] Endl.) forest. Data were collected on fuel, forest structure, and understory species composition and compared between treatments. Downed woody fuel, duff depth, litter depth, and density of live woody fuels were found to be significantly lower on sites treated with fire compared to unburned sites. Density of the dominant overstory canopy species, coast redwood and Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco), remained consistent between treatments, and the abundance of herbaceous understory plant species was not significantly altered by burning. In addition, both downed woody fuel and live fuel measures were positively correlated with time since last burn, with the lowest measures on the most recently burned sites. Conclusions Our results indicated that the use of prescribed burning in old-growth redwood forests can provide beneficial reductions in live and dead surface fuels with minimal impacts to overstory trees and understory herbaceous species.

Understory species composition and production in old-growth western hemlock – Sitka spruce forests of southeastern Alaska

1997 ◽  
Vol 75 (4) ◽  
pp. 574-580 ◽  
Author(s):  
Thomas A. Hanley ◽  
Ward W. Brady
Keyword(s):  
Species Composition ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Thuja Plicata ◽  
Stand Age ◽  
Soil Drainage ◽  
Site Factors ◽  
Old Growth ◽  
Understory Species ◽  
Understory Species Composition

Vascular understory species composition and production were studied in 36 stands in both northern and southern portions of southeastern Alaska, United States. Understory composition and production were related to site factors of soil drainage and slope and overstory factors of species composition, stand age, canopy coverage, and mass (net wood volume). Principal floristic gradients were dominated by differences in production of Alaska blueberry (Vaccinium alaskaense How.), skunk-cabbage (Lysichiton americanum Huit. & St. John), and lady fern (Athyrium filix-femina (L.) Roth). Soil drainage was the principal environmental factor determining understory species composition. Soil drainage also determined overstory mass and, consequently, total understory production, presumably through effects of overstory mass on light interception. Well-drained sites were more productive of trees and less productive of understory than were poorly drained sites. Relations between windthrow, soil drainage, overstory mass, and understory species composition and production are interactive in these excessively wet, old-growth forests. Key words: plant communities, biomass, forest overstory, temperate rain forest, Tsuga heterophylla, Picea sitchensis, Thuja plicata, western red cedar.

Genotypic diversity and clone size in old-growth populations of coast redwood (Sequoia sempervirens)

2000 ◽  
Vol 78 (11) ◽  
pp. 1408-1419 ◽  
Author(s):  
Deborah L Rogers
Keyword(s):  
Asexual Reproduction ◽  
Genotypic Diversity ◽  
Visual Assessment ◽  
Sequoia Sempervirens ◽  
Allozyme Diversity ◽  
Old Growth ◽  
Clone Size ◽  
Coast Redwood ◽  
Ring Structures ◽  
Individual Trees

Coast redwood (Sequoia sempervirens (D. Don) Endl.) has long-lived individual trees that can reproduce both sexually and asexually. Allozyme markers indicate that, in old-growth populations in northern California, 15-34% of clones are multistemmed. Of those, they have few stems per clone, and none are very spatially pervasive. There is much variety in the clonal configurations observed, including circular, linear, and (or) disjunct arrangements. Visual assessment is a poor predictor of clonal identity and fairy ring structures more often than not contain multiple genotypes. In this first allozyme study of coast redwood, high levels of genetic variation are observed, higher than those observed for most other western conifers. These levels are perhaps related to the species' hexaploid condition, ancient phylogenetic lineage, and historically broader natural range. There are also generally high levels of genotypic diversity. Upland sites, with more frequent and intense fires, do not differ significantly in genotypic diversity from the more mesic lowland sites. Population structure in coast redwood seems to resemble the classic pattern for many open-pollinated conifers: much diversity within and little among populations. However, this is not a rangewide study. The current levels and structure of genetic and genotypic diversity in old-growth populations suggests episodic recruitment. The long-lived nature of individual stems and the capacity for asexual reproduction may allow clones to exist indefinitely, thus challenging some of the generalizations in evolutionary theory that are based on sexually reproducing species.Key words: clones, asexual reproduction, allozyme diversity, conifer, gymnosperm, polyploid.

scholarly journals The Influences of Canopy Species and Topographic Variables on Understory Species Diversity and Composition in Coniferous Forests

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hong Huo ◽  
Qi Feng ◽  
Yong-hong Su
Keyword(s):  
Species Composition ◽  
Variation Partitioning ◽  
Explanatory Power ◽  
Coniferous Forest ◽  
Coniferous Forests ◽  
Spruce Forest ◽  
Understory Species ◽  
Sabina Przewalskii ◽  
Understory Species Composition ◽  
Understory Plant

Understanding the factors that influence the distribution of understory vegetation is important for biological conservation and forest management. We compared understory species composition by multi-response permutation procedure and indicator species analysis between plots dominated by Qinghai spruce (Picea crassifoliaKom.) and Qilian juniper (Sabina przewalskiiKom.) in coniferous forests of the Qilian Mountains, northwestern China. Understory species composition differed markedly between the forest types. Many heliophilous species were significantly associated with juniper forest, while only one species was indicative of spruce forest. Using constrained ordination and the variation partitioning model, we quantitatively assessed the relative effects of two sets of explanatory variables on understory species composition. The results showed that topographic variables had higher explanatory power than did site conditions for understory plant distributions. However, a large amount of the variation in understory species composition remained unexplained. Forward selection revealed that understory species distributions were primarily affected by elevation and aspect. Juniper forest had higher species richness andα-diversity and lowerβ-diversity in the herb layer of the understory plant community than spruce forest, suggesting that the former may be more important in maintaining understory biodiversity and community stability in alpine coniferous forest ecosystems.

Presettlement and modern disturbance regimes in coast redwood forests: Implications for the conservation of old-growth stands

2009 ◽  
Vol 258 (7) ◽  
pp. 1038-1054 ◽  
Author(s):  
Craig G. Lorimer ◽  
Daniel J. Porter ◽  
Mary Ann Madej ◽  
John D. Stuart ◽  
Stephen D. Veirs ◽  
...  
Keyword(s):  
Old Growth ◽  
Coast Redwood ◽  
Disturbance Regimes ◽  
Redwood Forests

scholarly journals Initial Floristic Response to High Severity Wildfire in an Old-Growth Coast Redwood (Sequoia sempervirens (D. Don) Endl.) Forest

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1135
Author(s):  
Mojgan Mahdizadeh ◽  
Will Russell
Keyword(s):  
Vegetation Type ◽  
Survival Rates ◽  
Tree Height ◽  
Fire Frequency ◽  
Sequoia Sempervirens ◽  
Type Conversion ◽  
Old Growth ◽  
Fire Event ◽  
Coast Redwood ◽  
High Severity

Climate driven increases in fire frequency and severity are predicted for Mediterranean climatic zones, including the Pacific coast of California. A recent high severity wildfire that burned in the Santa Cruz Mountains affected a variety of vegetation types, including ancient coast redwood (Sequoia sempervirens (D. Don) Endl.) stands. The purpose of this study was to characterize the survival and initial recovery of vegetation approximately six months after the fire. We sampled thirty randomly selected points in an old-growth coast redwood forest to examine and compare survival, crown retention, and post fire regeneration of trees by species, and the recovery of associated understory plant species. Sequoia sempervirens exhibited the highest post-fire survival (95%), with lower survival rates for subcanopy hardwood associates including tanoak (Notholithocarpus densiflorus (Hook. & Arn.) Manos) (88%), coast live oak (Quercus agrifolia Nee.) (93%), Pacific wax myrtle (Myrica californica (Cham. & Schltdl.) Wilbur) (75%), Pacific madrone (Arbutus menziesii Pursh) (71%), and the lowest survival recorded for the canopy codominant Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) (15%). Canopy retention and post fire regeneration were also highest for S. sempervirens and lowest for P. menziesii, indicating that S. sempervirens had a competitive advantage over P. menziesii following high severity crown fire. Both canopy survival and regeneration were greater for larger height and diameter trees; and basal sprouting was positively associated with tree height and diameter for S. sempervirens and N. densiflorus. Observed recovery of understory species was modest but included the reemergence of coast redwood associated herbaceous species. The robust nature of survival and recovery of S. sempervirens following this extreme fire event suggest that the removal of scorched, and the seeding or planting of trees, following this type of fire is contraindicated. The decline of P. menziesii is of concern, however, and suggests that repeated high severity fires driven by climate change could eventually lead to vegetation type conversion.

Sign in / Sign up

Export Citation Format

Share Document