Testing the effects of species interactions and water limitation on tree seedling biomass allocation and physiology

2021 ◽  
Author(s):  
Kelly L Kerr ◽  
Nicole Zenes ◽  
Anna T Trugman ◽  
William R L Anderegg
Keyword(s):  
Populus Tremuloides ◽  
Biomass Allocation ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Species Interactions ◽  
Water Status ◽  
Physiological Traits ◽  
Plant Interactions ◽  
Tree Seedling ◽  
Water Limitation

Abstract Species interactions mediate tree responses to water limitation because competition and/or facilitation alter plant physiology and growth. However, because it is difficult to isolate the effects of plant–plant interactions and water limitation from other environmental factors, the mechanisms underlying tree physiology and growth in coexisting plants under drought are poorly understood. We investigated how species interactions and water limitation impact the physiology and growth of trembling aspen (Populus tremuloides), narrowleaf cottonwood (Populus angustifolia) and ponderosa pine (Pinus ponderosa) seedlings in a controlled environment growth chamber, using aspen as a focal species. Seedlings were grown in pots alone or with a con- or hetero-specific seedling, and were subjected to a water limitation treatment. Growth, water status and physiological traits were measured before, during and after the treatment. Under well-watered conditions, the presence of another seedling affected growth or biomass allocation in all species, but did not impact the physiological traits we measured. Under water limitation, the presence of a competing seedling had a marginal impact on seedling growth and physiological traits in all species. Throughout the study, the magnitude and direction of seedling responses were complex and often species-specific. Our study serves as an important step toward testing how species’ interactions modify physiological responses and growth in well-watered and water-limited periods.

The Effect of Cattle Grazing on Ponderosa Pine Regeneration

1991 ◽  
Vol 67 (3) ◽  
pp. 245-248 ◽  
Author(s):  
J. L. Kingery ◽  
R. T. Graham
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Habitat Type ◽  
Total Mortality ◽  
Cattle Grazing ◽  
Nez Perce ◽  
Tree Seedlings ◽  
Tree Seedling ◽  
Pine Regeneration ◽  
Study Sites

During the summer and fall of 1982, a study was established on the Nez Percé National Forest in central Idaho to assess the effects of cattle grazing on the performance of a new ponderosa pine (Pinus ponderosa Laws.) plantation. Three study sites were located in a Douglas-fir/ninebark (Pseudotsuga menziesii/Physocarpus malvaceus) habitat type. Results after six years showed that livestock use can influence tree seedling establishment. Mortality and damage to tree seedlings from cattle resulted primarily from trampling rather than from browsing. Five and one-half percent of the seedlings were damaged by cattle, of which 3.6% died. Browsing by deer and elk caused the most growth loss. Overall damage was greatest from non-animal causes. Seedling quality at the time of planting, handling of the seedling, and droughty conditions during the first two years of the study contributed to this type of damage. Overall performance of the tree seedlings were relatively poor. Total mortality to tree seedlings resulting from all sources of damage was 43.6% for the grazed treatment and 25.3% for the non-grazed treatment.

scholarly journals Plant–plant interactions vary with different mycorrhizal fungus species

2005 ◽  
Vol 1 (4) ◽  
pp. 439-442 ◽  
Author(s):  
Jason D Hoeksema
Keyword(s):  
Plant Growth ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Mycorrhizal Fungi ◽  
Plant Density ◽  
Mycorrhizal Fungus ◽  
Species Variation ◽  
Plant Interactions ◽  
Fungus Species ◽  
Plant Plant

Because different species of mycorrhizal fungi have different effects on the growth of particular plant species, variation in mycorrhizal fungus species composition could cause changes in the strength of plant–plant interactions. Results are presented from a growth chamber experiment that compared the strength of interactions among seedlings of ponderosa pine ( Pinus ponderosa ) when the pines were colonized by two different groups of ectomycorrhizal fungi in the genus Rhizopogon . Plant density effects differed between the two groups of mycorrhizal fungi: plant growth was low regardless of density when plants were colonized with pine-specific Rhizopogon species, while plant growth declined with plant density when plants were colonized by Rhizopogon species having a broader host range. This result parallels results from previous studies showing that plant interactions are more antagonistic with mycorrhizal fungi than without, implying that plant responsiveness to beneficial mycorrhizal fungi declines with increasing plant density. If such effects are prevalent in plant communities, then variation in mycorrhizal fungus community composition is predicted to have a density-dependent effect on plants.

scholarly journals Historical forest changes in the western United States

2020 ◽  
Vol 96 (01) ◽  
pp. 36-49
Author(s):  
Craig Loehle
Keyword(s):  
United States ◽  
Populus Tremuloides ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Fire Regimes ◽  
Forest Growth ◽  
Western United States ◽  
Past Century ◽  
Growth Trends ◽  
The Past

Changes in factors such as temperature, precipitation, fire regimes, ozone, atmospheric CO2, and nitrogen deposition may have altered forest growth over the past century. Determining changes in forest growth over long intervals is complicated by constantly changing growing conditions due to tree maturation, stand self-thinning, disturbance, and other factors. Because a comprehensive review is lacking, results from publications examining forest growth trends in the western United States over the past 100 years were evaluated. Across the region, upper elevational forest ecotones have been expanding upward in many but not all locations, possibly due to warming and reduced snowpack. Across most of the region, both growth increases and decreases are localized and spatially dispersed. For the inland West, historical photography and long-term inventory data show clear densification and expansion of ponderosa pine (Pinus ponderosa) and mixed conifer forest across the region, mostly due to reduced fire incidence. However, a recent drought, probably linked to ocean cycles and exacerbated by warming, has caused a growth setback and mortality, especially in the Southwest. Forest densification due to altered fire regimes does not equate to enhanced growth per se. Aspen (Populus tremuloides) dieback has been noted due to recent drought and local conifer mortality caused by drought has also been documented in several locations. Regeneration after recent fires appears to be inadequate in many localities. Except for local increased growth at some high elevation and coastal sites and possible periodic drought effects in the Southwest, it is difficult to detect any growth trends with available data.

scholarly journals Evaluation of Physical Barriers to Protect Ponderosa Pine Seedlings from Pocket Gophers

1999 ◽  
Vol 14 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Michael J. Pipas ◽  
Gary W. Witmer
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Seedling Mortality ◽  
Pocket Gophers ◽  
Thomomys Talpoides ◽  
Pine Seedlings ◽  
Physical Barriers ◽  
Growth Of Seedlings ◽  
Medium Weight ◽  
Better Than

Abstract A 2 yr study on the Rogue River and Mt. Hood National Forests in Oregon evaluated physical barriers for protection of Pinus ponderosa seedlings against damage by Thomomys talpoides. Seedlings protected with one of three weights of: (1) plastic mesh tubing (Vexar®) or (2) sandpapertubing (Durite®) were evaluated against control seedlings. On the Rogue River sites, Vexar® seedlings had the highest survival (62.6%), followed by the controls (59.1%), then Durite® seedlings (17.9%). Gophers were the primary cause of death for the Vexar® seedlings, versus desiccation for the Durite® seedlings. On the Mt. Hood sites, heavyweight Vexar® seedlings had the highest survival (35.4%), medium-weight Durite® seedlings the lowest (2.7%). Seedling mortality caused by gophers was highest for controls (70.2%), followed by light-weight (62.2%) and heavy-weight (53.9%) Vexar® treatments. Overall survival was low (Rogue River = 42%, Mt. Hood = 19.8%). Growth was greatest for the control seedlings but only significantly greater than growth of Durite® seedlings on the Rogue River sites. Growth of seedlings was not compromised by the Vexar® tubing. Although neither type of tubing was highly protective, Vexar® tubes performed better than Durite® tubes. West. J. Appl. For. 14(3):164-168.

Impact of the colonization of Leifsonia xyli subsp. xyli in a susceptible sugarcane genotype on water status and physiological traits

2021 ◽  
Author(s):  
Fernando Henrique Silva Garcia ◽  
Timóteo Herculino da Silva Barros ◽  
Rubens Duarte Coelho ◽  
Marie Caroline Ferreira Laborde ◽  
Ricardo Antunes Azevedo ◽  
...  
Keyword(s):  
Water Status ◽  
Physiological Traits

scholarly journals Germination, Establishment, and Mortality of Naturally Seeded Southwestern Ponderosa Pine

2003 ◽  
Vol 18 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Steven J. Stein ◽  
Diana N. Kimberling
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Mineral Soil ◽  
Mortality Data ◽  
Mortality Factors ◽  
Seedling Mortality ◽  
Prescribed Burns ◽  
Factors Affecting ◽  
Northern Arizona ◽  
Lepidopteran Larvae

Abstract Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.

Reproductive output of ponderosa pine in response to thinning and prescribed burning in western Montana

2008 ◽  
Vol 38 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Gregory Peters ◽  
Anna Sala
Keyword(s):  
Pinus Ponderosa ◽  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Reproductive Output ◽  
Management Practices ◽  
Prescribed Burning ◽  
Seed Mass ◽  
Reproductive Traits ◽  
Western Montana ◽  
Cone Production

Thinning and thinning followed by prescribed fire are common management practices intended to restore historic conditions in low-elevation ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the northern Rocky Mountains. While these treatments generally ameliorate the physiology and growth of residual trees, treatment-specific effects on reproductive output are not known. We examined reproductive output of second-growth ponderosa pine in western Montana 9 years after the application of four treatments: thinning, thinning followed by spring prescribed fire, thinning followed by fall prescribed fire, and unthinned control stands. Field and greenhouse observations indicated that reproductive traits vary depending on the specific management treatment. Cone production was significantly higher in trees from all actively managed stands relative to control trees. Trees subjected to prescribed fire produced cones with higher numbers of filled seeds than trees in unburned treatments. Seed mass, percentage germination, and seedling biomass were significantly lower for seeds from trees in spring burn treatments relative to all others and were generally higher in trees from fall burn treatments. We show for the first time that thinning and prescribed-burning treatments can influence reproductive output in ponderosa pine.

Vascular cambium necrosis in forest fires: using hyperbolic temperature regimes to estimate parameters of a tissue-response model

2004 ◽  
Vol 52 (6) ◽  
pp. 757 ◽  
Author(s):  
M. B. Dickinson ◽  
J. Jolliff ◽  
A. S. Bova
Keyword(s):  
Pinus Ponderosa ◽  
Forest Fires ◽  
Ponderosa Pine ◽  
Process Model ◽  
Acer Rubrum ◽  
Tissue Response ◽  
Vascular Cambium ◽  
Red Maple ◽  
Fixed Temperature ◽  
Temperature Regimes

Hyperbolic temperature exposures (in which the rate of temperature rise increases with time) and an analytical solution to a rate-process model were used to characterise the impairment of respiration in samples containing both phloem (live bark) and vascular-cambium tissue during exposures to temperatures such as those experienced by the vascular cambium in tree stems heated by forest fires. Tissue impairment was characterised for red maple (Acer rubrum), chestnut oak (Quercus prinus), Douglas fir (Pseudotsuga menziesii), and ponderosa pine (Pinus ponderosa) samples. The estimated temperature dependence of the model’s rate parameter (described by the Arrhenius equation) was a function of the temperature regime to which tissues were exposed. Temperatures rising hyperbolically from near ambient (30°C) to 65°C produced rate parameters for the deciduous species that were similar at 60°C to those from the literature, estimated by using fixed temperature exposures. In contrast, samples from all species showed low rates of impairment, conifer samples more so than deciduous, after exposure to regimes in which temperatures rose hyperbolically between 50 and 60°C. A hypersensitive response could explain an early lag in tissue-impairment rates that apparently caused the differences among heating regimes. A simulation based on stem vascular-cambium temperature regimes measured during fires shows how temperature-dependent impairment rates can be used to predict tissue necrosis in fires. To our knowledge, hyperbolic temperature exposures have not been used to characterise plant tissue thermal tolerance and, given certain caveats, could provide more realistic data more efficiently than fixed-temperature exposures.

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