scholarly journals Assessing Tree Drought Resistance and Climate-Growth Relationships under Different Tree Age Classes in a Pinus nigra Arn. ssp. salzmannii Forest

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1161
Author(s):  
Manuel Esteban Lucas-Borja ◽  
Arun K. Bose ◽  
Enrique Andivia ◽  
David Candel-Pérez ◽  
Pedro A. Plaza-Álvarez ◽  
...  
Keyword(s):  
Water Balance ◽  
Drought Resistance ◽  
Basal Area ◽  
Pinus Nigra ◽  
Tree Age ◽  
Black Pine ◽  
Growth Reduction ◽  
Age Classes ◽  
Commercial Thinning ◽  
Large Trees

The magnitude of drought impact in forest ecosystems depends on which group of trees are more severely affected; greater mortality of smaller trees can modulate the trajectories of succession, while the mortality of larger trees can disproportionately offset the ecosystem’s carbon balance. Several studies have documented a greater vulnerability of large trees to extreme droughts while some other studies reported a greater growth reduction in smaller trees during droughts. We tested these hypotheses by comparing tree basal area increment (BAI), drought resistance (i.e., magnitude of growth decline during drought), and resilience (i.e., magnitude of growth recovery after drought) across five different age-classes in black pine (Pinus nigra Arn. Ssp salzmannii) forests in Spain. Our results showed that the BAI patterns, drought resistance, and resilience were strongly influenced by tree age-classes. In addition, the effect of climatic water balance (precipitation minus potential evapotranspiration) on BAI significantly varied among age-classes. The effect of water balance on BAI was lower for younger age-classes (1–39 years of age) compared to older age-classes. We observed a greater growth reduction (i.e., lower resistance) in older trees (>40 years of age) during droughts compared to younger trees (<40 years of age). However, all trees, irrespective of their ages, were able to recover the growth rates after the drought. In general, younger trees showed a greater capacity in recovering the growth rate (i.e., more resilient) than older trees. We detected no significant effects of stand basal area and stand density on BAI, drought resistance, and resilience. Overall, our results indicated that growth of older trees was more negatively affected during drought. Therefore, these older/larger trees can be selected for commercial thinning, or can be released from competition, which can minimize the potential impacts of future droughts in black pine forests in Spain.

Large herbivores control the invasive potential of nonnative Austrian black pine in a mixed deciduous Mediterranean forest

2006 ◽  
Vol 36 (4) ◽  
pp. 1047-1053 ◽  
Author(s):  
Sandrine Chauchard ◽  
Gaëlle Pille ◽  
Christopher Carcaillet
Keyword(s):  
Age Structure ◽  
Structural Changes ◽  
Deciduous Forest ◽  
Bos Taurus ◽  
Pinus Nigra ◽  
Tree Age ◽  
Black Pine ◽  
Invasive Potential ◽  
Large Herbivores ◽  
Eastern Pyrenees

The invasive potential of the nonnative Austrian black pine (Pinus nigra subsp. nigra Arn.) was analyzed in a 100-year-old Mediterranean mixed deciduous forest in the Massane Nature Reserve, eastern Pyrenees (France). The reserve holds approximately 120–150 semiferal cattle (Bos taurus L.) that browse and trample the woody regeneration. Tree age structure was assessed by dendrochronology to reconstruct the pine population dynamics in grazed and nongrazed (fenced in 1954) portions of the forested reserve. The age structure of the pine population regenerating before 1960 was similar between the inside and outside of the enclosed reserve area. Since 1960, pine recruitment has occurred only in the nongrazed area. The diameter variability with age changed since the 19th century. For pines less than 20 years old, the diameter variability is low, whereas it is very high for individuals older than 100 years. Diverse forest structural changes (composition, canopy height, density, etc.) likely explain the variability in diameter at a given age. Cattle do not appear to affect tree growth as it is similar inside and outside the fenced area, but they control the regeneration of nonnative Austrian black pines, which can spread in the absence of cattle. If nonnative black pine poses a risk for forest conservation, large herbivores may play a useful role in maintaining this species at low abundance.

scholarly journals A Crown Width-Diameter Model for Natural Even-Aged Black Pine Forest Management

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 610 ◽  
Author(s):  
Dimitrios Raptis ◽  
Vassiliki Kazana ◽  
Angelos Kazaklis ◽  
Christos Stamatiou
Keyword(s):  
Forest Management ◽  
Nonlinear Models ◽  
Management Practice ◽  
Basal Area ◽  
Field Measurements ◽  
Pinus Nigra ◽  
Least Square ◽  
Black Pine ◽  
Mixed Effect ◽  
Crown Width

Crown size estimations are of vital importance in forest management practice. This paper presents nonlinear models that were developed for crown width prediction of Black pine (Pinus nigra Arn.) natural, pure, even-aged stands in Olympus Mountain, central Greece. Using a number of measured characteristics at tree and plot level from 66 sample plots as independent variables, an attempt was made to predict crown width accurately, initially based on Least Square Analysis. At the second stage, nonlinear mixed effect modeling was performed in order to increase the fitting ability of the proposed models and to deal with the lack of between observations independence error assumption. Based on the same form, a generalized crown width model was developed by including six main regressors, such as the diameter at breast height, the total height, the canopy base height, the basal area, the relative spacing index and the diameter to quadratic mean diameter ratio, while at the final stage, the same model was expanded to mixed-effect. The proposed models were evaluated against independent crown width sample observations that were also obtained from the study area. The results showed that the two types of mixed-effect models performed equally well and, therefore, we propose those for use in forestry practice. Furthermore, the exact contribution of each inherent variable in crown width allometry was evaluated, thus providing a framework to facilitate field measurements for forest management predictions.

scholarly journals Effects of Thinning on Dynamics and Drought Resistance of Aspen-White Spruce Mixtures: Results From Two Study Sites in Saskatchewan

2021 ◽  
Vol 3 ◽  
Author(s):  
Philip G. Comeau
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Basal Area ◽  
White Spruce ◽  
Tree Size ◽  
Average Height ◽  
Negative Effects ◽  
Positive Effects ◽  
Commercial Thinning ◽  
Study Sites

Drought stress associated with warm temperatures is causing increased mortality and reduced growth of trees in drier portions of the boreal forests of western Canada with both warming and drought expected to increase over the coming decades. While thinning is often shown to reduce drought stress, there is little information on its effects in stands comprised of mixtures of trembling aspen and white spruce that are common in the forests of this region. This study examined effects of pre-commercial thinning on aspen and spruce growth, response to drought stress, and stand dynamics for two study sites located in Saskatchewan, Canada. In unthinned plots aspen densities declined from initial densities of 40,000 to 200,000 trees ha−1 to 2,639 trees ha−1 at age 26. Twenty-one years after thinning (i.e., at age 26) diameter of aspen and spruce had increased, with largest trees being found at the lowest aspen densities (200 aspen ha−1 for aspen and 0 aspen ha−1 for spruce). Aspen density affected average height but not height of aspen top height trees. Spruce height decreased significantly with increasing aspen density. Crown width and live crown ratio of both aspen and spruce declined with increasing aspen density. Data from cores collected from aspen and spruce indicate significant positive effects of tree size (basal area at beginning of the year), and CMI (Climate Moisture Index) on basal area increment of both aspen and spruce while increasing aspen basal area (m2ha−1) had negative effects on aspen and spruce growth. Increasing tree size (basal area) and aspen competition (basal area ha−1) both had negative effects on drought resistance and resilience for both aspen and spruce. Yield projections provided by the Mixedwood Growth Model (MGM) suggest that the mixture of 1,500 aspen ha−1 and 1,000 spruce ha−1 has the potential to provide a 23% increase in total mean annual increment (MAI) with a single harvest at age 100, compared to unthinned aspen stands, but with a 44% reduction in spruce MAI compared to pure spruce stands. Thinning of aspen to densities below 4,000 trees ha−1 at age 5 resulted in reduced aspen yields but increased spruce yields.

scholarly journals Onset of canopy closure for black pine, Turkish red pine and Scots pine forests

2018 ◽  
Vol 64 (No. 5) ◽  
pp. 224-229 ◽  
Author(s):  
Kara Ferhat ◽  
Topaçoğlu Osman
Keyword(s):  
Scots Pine ◽  
Basal Area ◽  
Stand Density ◽  
Pinus Nigra ◽  
Red Pine ◽  
Pine Forests ◽  
Canopy Closure ◽  
Black Pine ◽  
Scots Pine Forests ◽  
Turkish Red Pine

Canopy closure plays an important role in regeneration and management activities in forestry. Thus, determining the density at which canopy closure occurs is important for the success of silvicultural treatments. Turkish red pine (Pinus brutia Tenore), black pine (Pinus nigra J.F. Arnold) and Scots pine (Pinus sylvestris Linnaeus) forests are usually managed at a density that is near or below the canopy closure. Residual stand density during the management of these species is commonly described by stand basal area – BA (m<sup>2</sup>·ha<sup>–1</sup>), however, the BA levels for the canopy closure have not been clearly indicated for these species. The minimum density for the onset of canopy closure (D<sub>OCC</sub>) was determined for Turkish red pine, black pine and Scots pine forests in this study. D<sub>OCC</sub> values were compared across the species. For the D<sub>OCC</sub>, the maximum tree area that a tree can occupy under open-grown conditions was used. The D<sub>OCC</sub> curves of black pine and Scots pine seem to be similar, but the canopy closure in Turkish red pine forests occurs with fewer trees per hectare for a given mean tree diameter. According to the D<sub>OCC</sub> curves, regeneration and tending activities will be more practical and effective in these forests.

scholarly journals Age-dependent climate–growth relationships and regeneration ofPicea abiesin a drought-prone mixed-coniferous forest in the Alps

2013 ◽  
Vol 43 (7) ◽  
pp. 609-618 ◽  
Author(s):  
Roman Schuster ◽  
Walter Oberhuber
Keyword(s):  
Radial Growth ◽  
Coniferous Forest ◽  
Basal Area ◽  
Tree Age ◽  
Age Classes ◽  
Competitive Strength ◽  
Age Dependent ◽  
The Alps ◽  
Forest Distribution ◽  
Alpine Environments

Within dry inner Alpine environments, climate warming is expected to affect the development of forest ecosystems by changing species composition and inducing shifts in forest distribution. By applying dendroecological techniques we evaluated the climate sensitivity of radial growth and the establishment of Picea abies (L.) Karst. in a drought-prone mixed-coniferous forest in the Austrian Alps. Time series of annual increments were developed from >220 trees and assigned to four age classes. While radial growth of old P. abies trees (mean ages of 121 and 174 years) had highly significant responses to May–June precipitation, young trees (mean ages 28 and 53 years) were insensitive to precipitation in the current year. Because tree age was closely correlated to height and diameter (r2= 0.709 and 0.784, respectively), we relate our findings to the increase in tree size rather than age per se. The synchronicity found among trends in basal area increment and tree establishment suggests that canopy openings increased light and water availability, which favoured growth and establishment of moderately shade-tolerant P. abies. We conclude that, although P. abies is able to regenerate at this drought-prone site, increasing inter-tree competition for water in dense stands gradually lowers competitive strength and restricts scattered occurrence to dry–mesic sites.

scholarly journals Big trees drive forest structure patterns across a lowland Amazon regrowth gradient

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tassiana Maylla Fontoura Caron ◽  
Victor Juan Ulises Rodriguez Chuma ◽  
Alexander Arévalo Sandi ◽  
Darren Norris
Keyword(s):  
Forest Structure ◽  
Natural Regeneration ◽  
Basal Area ◽  
Significant Decline ◽  
Forest Regrowth ◽  
Large Trees ◽  
Amazonian Forests ◽  
Mammal Diversity ◽  
Structure Patterns ◽  
Plot Type

AbstractDegraded Amazonian forests can take decades to recover and the ecological results of natural regeneration are still uncertain. Here we use field data collected across 15 lowland Amazon smallholder properties to examine the relationships between forest structure, mammal diversity, regrowth type, regrowth age, topography and hydrology. Forest structure was quantified together with mammal diversity in 30 paired regrowth-control plots. Forest regrowth stage was classified into three groups: late second-regrowth, early second-regrowth and abandoned pasture. Basal area in regrowth plots remained less than half that recorded in control plots even after 20–25 years. Although basal area did increase in sequence from pasture, early to late-regrowth plots, there was a significant decline in basal area of late-regrowth control plots associated with a decline in the proportion of large trees. Variation in different forest structure responses was explained by contrasting variables, with the proportion of small trees (DBH < 20 cm) most strongly explained by topography (altitude and slope) whereas the proportion of large trees (DBH > 60 cm) was explained by plot type (control vs. regrowth) and regrowth class. These findings support calls for increased efforts to actively conserve large trees to avoid retrogressive succession around edges of degraded Amazon forests.

Effect of traffic-induced air pollution on seed germination of Arizona Cypress (Cupressus arizonica Green) and Black Pine (Pinus nigra Arnold)

2020 ◽  
Vol 55 ◽  
pp. 126841
Author(s):  
Zahra Babapour Aliyar ◽  
Abbas Banj Shafiei ◽  
Nasrin Seyedi ◽  
Salar Rezapour ◽  
Saeed Musavi Moghanjugi
Keyword(s):  
Air Pollution ◽  
Seed Germination ◽  
Pinus Nigra ◽  
Black Pine ◽  
Cupressus Arizonica

Root rot damage in naturally regenerated stands of spruce and balsam fir in Ontario

1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney
Keyword(s):  
Root Rot ◽  
Black Spruce ◽  
Basal Area ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Tree Age ◽  
Stand Age ◽  
Root Decay ◽  
Forest Region

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.

scholarly journals Drought resistance of sugar-cane crop for different levels of water availability in the soil

2014 ◽  
Vol 34 (2) ◽  
pp. 203-210 ◽  
Author(s):  
Fernando da S. Barbosa ◽  
Rubens D. Coelho ◽  
Rafael Maschio ◽  
Carlos J. G. de S. Lima ◽  
Everaldo M. da Silva
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Deficit ◽  
Early Development ◽  
Drought Resistance ◽  
Sugar Cane ◽  
Water Availability ◽  
Sandy Loam ◽  
Final Population ◽  
Different Levels

Soil water availability is the main cause of reduced productivity, and the early development period most sensitive to water deficit. This study aimed to evaluate the drought resistance of the varieties of sugar-cane RB867515 and SP81-3250 during the early development using different levels of water deficit on four soil depths. The experiment was conducted at the Department of Biosystems at Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP) in a greenhouse in soil classified as Oxisol, sandy loam texture (Series "Sertãozinho"). Once exhausted the level of available water in the soil, the dry strength of the studied strains are relatively low. Water balance with values less than -13 mm cause a significant decrease in the final population of plants, regardless of the variety, and values below -35 mm, leads to the death of all plants.

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