- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Faculty Research and Publications /
- Difference in Regeneration Conditions in Pinus ponderosa...
Open Collections
UBC Faculty Research and Publications
Difference in Regeneration Conditions in Pinus ponderosa Dominated Forests in Northern California, USA, over an 83 Year Period Nepal, Sushil; Eskelson, Bianca N. I.; Ritchie, Martin W.
Abstract
Forest inventories based on field surveys can provide quantitative measures of regeneration such as density and stocking proportion. Understanding regeneration dynamics is a key element that supports silvicultural decision-making processes in sustainable forest management. The objectives of this study were to: (1) describe historical regeneration in ponderosa pine dominated forests by species and height class, (2) find associations of regeneration with overstory, soil, and topography variables, (3) describe contemporary regeneration across various management treatments, and (4) compare differences in regeneration between historical and contemporary forests. The study area, a ponderosa pine (Pinus ponderosae Dougl. ex P. and C. Law) dominated forest, is located within the Blacks Mountain Experimental Forest (BMEF) in northeastern California, United States, which was designated as an experimental forest in 1934. We used 1935 and 2018 field surveyed regeneration data containing information about three species—ponderosa pine, incense-cedar (Calocedrus decurrens (Torr.) Florin) and white fir (Abies concolor (Grod. and Glend)—and four height classes: class 1: 0–0.31 m, class 2: 0.31–0.91 m, class 3: 0.91–1.83 m, and class 4: >1.83 m and <8.9 cm diameter at breast height. We used stocking as proxy for regeneration density in this study. We found that historically, stocking in the BMEF was dominated by shade-intolerant ponderosa pine in height classes 2 and 3. Two variables—overstory basal area per hectare (m² ha⁻¹ ) and available water capacity at 150 cm, which is the amount of water that is available for plants up to a depth of 150 cm from the soil surface—were significantly associated with stocking, and a beta regression model fit was found to have a pseudo-R² of 0.49. We identified significant differences in contemporary stocking among six management scenarios using a Kruskal–Wallis non-parametric one-way ANOVA. Control compartments had the highest stocking followed by burned compartments. In contemporary forest stands, recent treatments involving a combination of burning and thinning resulted in high stocking in height classes 2 and 3. Overall, the stocking in historical BMEF stands was higher than in contemporary stands and was dominated by ponderosa pine.
Item Metadata
| Title |
Difference in Regeneration Conditions in Pinus ponderosa Dominated Forests in Northern California, USA, over an 83 Year Period
|
| Creator | |
| Publisher |
Multidisciplinary Digital Publishing Institute
|
| Date Issued |
2020-05-22
|
| Description |
Forest inventories based on field surveys can provide quantitative measures of regeneration
such as density and stocking proportion. Understanding regeneration dynamics is a key element that
supports silvicultural decision-making processes in sustainable forest management. The objectives
of this study were to: (1) describe historical regeneration in ponderosa pine dominated forests by
species and height class, (2) find associations of regeneration with overstory, soil, and topography
variables, (3) describe contemporary regeneration across various management treatments, and (4)
compare differences in regeneration between historical and contemporary forests. The study area,
a ponderosa pine (Pinus ponderosae Dougl. ex P. and C. Law) dominated forest, is located within the
Blacks Mountain Experimental Forest (BMEF) in northeastern California, United States, which was
designated as an experimental forest in 1934. We used 1935 and 2018 field surveyed regeneration
data containing information about three species—ponderosa pine, incense-cedar (Calocedrus decurrens
(Torr.) Florin) and white fir (Abies concolor (Grod. and Glend)—and four height classes: class 1:
0–0.31 m, class 2: 0.31–0.91 m, class 3: 0.91–1.83 m, and class 4: >1.83 m and <8.9 cm diameter at
breast height. We used stocking as proxy for regeneration density in this study. We found that
historically, stocking in the BMEF was dominated by shade-intolerant ponderosa pine in height
classes 2 and 3. Two variables—overstory basal area per hectare (m² ha⁻¹
) and available water
capacity at 150 cm, which is the amount of water that is available for plants up to a depth of 150 cm
from the soil surface—were significantly associated with stocking, and a beta regression model
fit was found to have a pseudo-R² of 0.49. We identified significant differences in contemporary
stocking among six management scenarios using a Kruskal–Wallis non-parametric one-way ANOVA.
Control compartments had the highest stocking followed by burned compartments. In contemporary
forest stands, recent treatments involving a combination of burning and thinning resulted in high
stocking in height classes 2 and 3. Overall, the stocking in historical BMEF stands was higher than in
contemporary stands and was dominated by ponderosa pine.
|
| Subject | |
| Genre | |
| Type | |
| Language |
eng
|
| Date Available |
2020-05-28
|
| Provider |
Vancouver : University of British Columbia Library
|
| Rights |
CC BY 4.0
|
| DOI |
10.14288/1.0391064
|
| URI | |
| Affiliation | |
| Citation |
Forests 11 (5): 581 (2020)
|
| Publisher DOI |
10.3390/f11050581
|
| Peer Review Status |
Reviewed
|
| Scholarly Level |
Faculty
|
| Rights URI | |
| Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
CC BY 4.0