Reversal of human-induced vegetation changes in Sequoia National Park, California

1999 ◽  
Vol 29 (4) ◽  
pp. 399-412 ◽  
Author(s):  
D Graham Roy ◽  
John L Vankat
Keyword(s):  
Ponderosa Pine ◽  
National Park ◽  
Prescribed Burning ◽  
Pine Forest ◽  
Tree Density ◽  
Permanent Plots ◽  
Vegetation Changes ◽  
Sequoia National Park ◽  
Giant Sequoia ◽  
Ponderosa Pine Forest

We resampled 76 permanent plots that had been established in the woodlands and forests of Sequoia National Park in 1969. Our objectives were to describe vegetation changes in the tree and shrub layers and determine the effects of prescribed burning that began in the 1960s. We compared changes in species importance and tree size class distributions between sample dates and between burned and unburned plots. Species composition had remained similar in all nine vegetation types sampled except in the ponderosa pine forest where Pinus ponderosa Dougl. ex P. & C. Laws. decreased in importance from 28 to 15% and Abies concolor (Gord. & Glend.) Lindl. increased from 18 to 31%. Structural changes were more common, as tree density decreased in the blue oak woodland (19%), and live oak woodlands (15%), as well as in ponderosa pine forest (41%), white fir forest (5%), giant sequoia groves (39%), and red fir forest (24%). Decreases in density were greater in burned plots but occurred in unburned plots as well, indicating that prescribed fire and self-thinning contributed to decreases in density. Tree density was unchanged in the lodgepole and subalpine forests, but increased in the Jeffrey pine forest (58%). The decreases in tree density represent a reversal of earlier trends.

Lick Creek historic photographic series: a century of change in a ponderosa pine forest in western Montana, US

2018 ◽  
Author(s):  
Sharon M. Hood ◽  
Duncan C. Lutes ◽  
Justin S. Crotteau ◽  
Christopher R. Keyes ◽  
Anna Sala ◽  
...  
Keyword(s):  
Ponderosa Pine ◽  
Pine Forest ◽  
Western Montana ◽  
Ponderosa Pine Forest

Lack of Vesicular-Arbuscular Mycorrhizal Inoculum in a Ponderosa Pine Forest

Ecology ◽  
1984 ◽  
Vol 65 (6) ◽  
pp. 1755-1759 ◽  
Author(s):  
D. A. Kovacic ◽  
T. V. St. John ◽  
M. I. Dyer
Keyword(s):  
Ponderosa Pine ◽  
Arbuscular Mycorrhizal ◽  
Pine Forest ◽  
Vesicular Arbuscular ◽  
Ponderosa Pine Forest

scholarly journals HAIRY WOODPECKER WINTER ROOST CHARACTERISTICS IN BURNED PONDEROSA PINE FOREST

2007 ◽  
Vol 119 (1) ◽  
pp. 43-52 ◽  
Author(s):  
KRISTIN A. COVERT-BRATLAND ◽  
TAD C. THEIMER ◽  
WILLIAM M. BLOCK
Keyword(s):  
Ponderosa Pine ◽  
Pine Forest ◽  
Ponderosa Pine Forest

scholarly journals Eddy covariance fluxes of acyl peroxy nitrates (PAN, PPN and MPAN) above a Ponderosa pine forest

2009 ◽  
Vol 9 (2) ◽  
pp. 615-634 ◽  
Author(s):  
G. M. Wolfe ◽  
J. A. Thornton ◽  
R. L. N. Yatavelli ◽  
M. McKay ◽  
A. H. Goldstein ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Sierra Nevada ◽  
Ponderosa Pine ◽  
Molecular Diffusion ◽  
Pine Forest ◽  
Chemical Production ◽  
Relative Contribution ◽  
Peroxy Nitrates ◽  
Ponderosa Pine Forest ◽  
Measurement Period

Abstract. During the Biosphere Effects on AeRosols and Photochemistry EXperiment 2007 (BEARPEX-2007), we observed eddy covariance (EC) fluxes of speciated acyl peroxy nitrates (APNs), including peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN) and peroxymethacryloyl nitrate (MPAN), above a Ponderosa pine forest in the western Sierra Nevada. All APN fluxes are net downward during the day, with a median midday PAN exchange velocity of −0.3 cm s−1; nighttime storage-corrected APN EC fluxes are smaller than daytime fluxes but still downward. Analysis with a standard resistance model shows that loss of PAN to the canopy is not controlled by turbulent or molecular diffusion. Stomatal uptake can account for 25 to 50% of the observed downward PAN flux. Vertical gradients in the PAN thermal decomposition (TD) rate explain a similar fraction of the flux, suggesting that a significant portion of the PAN flux into the forest results from chemical processes in the canopy. The remaining "unidentified" portion of the net PAN flux (~15%) is ascribed to deposition or reactive uptake on non-stomatal surfaces (e.g. leaf cuticles or soil). Shifts in temperature, moisture and ecosystem activity during the summer – fall transition alter the relative contribution of stomatal uptake, non-stomatal uptake and thermochemical gradients to the net PAN flux. Daytime PAN and MPAN exchange velocities are a factor of 3 smaller than those of PPN during the first two weeks of the measurement period, consistent with strong intra-canopy chemical production of PAN and MPAN during this period. Depositional loss of APNs can be 3–21% of the gross gas-phase TD loss depending on temperature. As a source of nitrogen to the biosphere, PAN deposition represents approximately 4–19% of that due to dry deposition of nitric acid at this site.

Spatial and temporal variation in respiration in a young ponderosa pine forest during a summer drought

2001 ◽  
Vol 110 (1) ◽  
pp. 27-43 ◽  
Author(s):  
B.E Law ◽  
F.M Kelliher ◽  
D.D Baldocchi ◽  
P.M Anthoni ◽  
J Irvine ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Ponderosa Pine ◽  
Pine Forest ◽  
Spatial And Temporal Variation ◽  
Summer Drought ◽  
Ponderosa Pine Forest

scholarly journals Ponderosa Pine Regeneration, Wildland Fuels Management, and Habitat Conservation: Identifying Trade-Offs Following Wildfire

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 286 ◽  
Author(s):  
Victoria Donovan ◽  
Caleb Roberts ◽  
Carissa Wonkka ◽  
David Wedin ◽  
Dirac Twidwell
Keyword(s):  
Species Richness ◽  
Ponderosa Pine ◽  
Fire Management ◽  
Woody Debris ◽  
Pine Forest ◽  
Habitat Conservation ◽  
Fuels Management ◽  
Management Objectives ◽  
Pine Regeneration ◽  
Ponderosa Pine Forest

Increasing wildfires in western North American conifer forests have led to debates surrounding the application of post-fire management practices. There is a lack of consensus on whether (and to what extent) post-fire management assists or hinders managers in achieving goals, particularly in under-studied regions like eastern ponderosa pine forests. This makes it difficult for forest managers to balance among competing interests. We contrast structural and community characteristics across unburned ponderosa pine forest, severely burned ponderosa pine forest, and severely burned ponderosa pine forest treated with post-fire management with respect to three management objectives: ponderosa pine regeneration, wildland fuels control, and habitat conservation. Ponderosa pine saplings were more abundant in treated burned sites than untreated burned sites, suggesting increases in tree regeneration following tree planting; however, natural regeneration was evident in both unburned and untreated burned sites. Wildland fuels management greatly reduced snags and coarse woody debris in treated burned sites. Understory cover measurements revealed bare ground and fine woody debris were more strongly associated with untreated burned sites, and greater levels of forbs and grass were more strongly associated with treated burned sites. Wildlife habitat was greatly reduced following post-fire treatments. There were no tree cavities in treated burned sites, whereas untreated burned sites had an average of 27 ± 7.68 cavities per hectare. Correspondingly, we found almost double the avian species richness in untreated burned sites compared to treated burned sites (22 species versus 12 species). Unburned forests and untreated burned areas had the same species richness, but hosted unique avian communities. Our results indicate conflicting outcomes with respect to management objectives, most evident in the clear costs to habitat conservation following post-fire management application.

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