scholarly journals Influence of thinning intensity and canopy type on Scots pine stand and growth dynamics in a mixed managed forest

2016 ◽  
Vol 25 (2) ◽  
pp. e057 ◽  
Author(s):  
Irantzu Primicia ◽  
Rubén Artázcoz ◽  
Juan-Bosco Imbert ◽  
Fernando Puertas ◽  
María-del-Carmen Traver ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Growth Rates ◽  
Stand Structure ◽  
Growth Dynamics ◽  
Basal Area ◽  
Beech Forest ◽  
Annual Increment ◽  
Thinning Intensity ◽  
Canopy Type

Aim of the study: We analysed the effects of thinning intensity and canopy type on Scots pine growth and stand dynamics in a mixed Scots pine-beech forest. Area of the study: Western Pyrenees. Material and methods: Three thinning intensities were applied in 1999 (0, 20 and 30% basal area removed) and 2009 (0, 20 and 40%) on 9 plots. Within each plot, pure pine and mixed pine-beech patches are distinguished. All pine trees were inventoried in 1999, 2009 and 2014. The effects of treatments on the tree and stand structure variables (density, basal area, stand and tree volume), on the periodic annual increment in basal area and stand and tree volume, and on mortality rates, were analysed using linear mixed effects models. Main Results: The enhancement of tree growth was mainly noticeable after the second thinning. Growth rates following thinning were similar or higher in the moderate than in the severe thinning. Periodic stand volume annual increments were higher in the thinned than in the unthinned plots, but no differences were observed between the thinned treatments. We observed an increase in the differences of the Tree volume annual increment between canopy types (mixed < pure) over time in the unthinned plots, as beech crowns developed. Research highlights: Moderate thinning is suggested as an appropriate forest practice at early pine age in these mixed forests, since it produced higher tree growth rates than the severe thinning and it counteracted the negative effect of beech on pine growth observed in the unthinned plots.Keywords: competition; Fagus sylvatica L.; Pinus sylvestris L.; forest management; mortality; Mediterranean forest.

scholarly journals Species Mixing Effects on Height–Diameter and Basal Area Increment Models for Scots Pine and Maritime Pine

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 249 ◽  
Author(s):  
José Riofrío ◽  
Miren del Río ◽  
Douglas Maguire ◽  
Felipe Bravo
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Growth Models ◽  
Basal Area ◽  
Maritime Pine ◽  
Basal Area Increment ◽  
Mixing Effects ◽  
Basal Area Growth ◽  
Area Growth ◽  
Species Mixtures

Models that incorporate known species-mixing effects on tree growth are essential tools to properly design silvicultural guidelines for mixed-species stands. Here, we developed generalized height–diameter (h-d) and basal area growth models for mixed stands of two main forest species in Spain: Scots pine (Pinus sylvestris L.) and Maritime pine (Pinus pinaster Ait.). Mixed-effects models were fitted from plot measurement and tree rings data from 726 Scots pine and 693 Maritime pine trees from mixed and pure stands in the Northern Iberian Range in Spain, with the primary objective of representing interactions between the species where they are interspersed in mixtures of varying proportions. An independent dataset was used to test the performance of the h-d models against models previously fitted for monospecific stands of both species. Basal area increment models were evaluated using a 10-fold block cross-validation procedure. We found that species mixing had contrasting effects on the species in both models. In h-d models, the species-mixing proportion determined the effect of species interactions. Basal area growth models showed that interspecific competition was influential only for Maritime pine; however, these effects differed depending on the mode of competition. For Scots pine, tree growth was not restricted by interspecies competition. The combination of mixed-effect models and the inclusion of parameters expressing species-mixing enhanced estimates of tree height and basal area growth compared with the available models previously developed for pure stands. Although the species-mixing effects were successfully represented in the fitted models, additional model components for accurately simulating the stand dynamics of mixtures with Scots pine and Maritime pine and other species mixtures require similar model refinements. Upon the completion of analyses required for these model refinements, the degree of improvement in simulating growth in species mixtures, including the effects of different management options, can be evaluated.

Growth Reductions in Naturally Regenerated Southern Pine Stands in Alabama and Georgia

1991 ◽  
Vol 15 (2) ◽  
pp. 73-79 ◽  
Author(s):  
G. A. Ruark ◽  
C. E. Thomas ◽  
W. A. Bechtold ◽  
D. M. May
Keyword(s):  
Pinus Taeda ◽  
Growth Rates ◽  
Stand Structure ◽  
Basal Area ◽  
Stand Density ◽  
Site Quality ◽  
Usda Forest Service ◽  
Forest Inventory And Analysis ◽  
Pine Stands ◽  
Growth Differences

Abstract Data from Forest Inventory and Analysis (FIA) units of the USDA Forest Service were used to compare average annual stand-level basal area accretion onto survivor pines in naturally regenerated pine stands throughout Alabama and Georgia. Growth rates measured between 1972-82 were compared to growth rates during the previous 10-year survey cycle in each state. Separate analyses were conducted for loblolly (Pinus taeda), longleaf (P. palustris), shortleaf (P. echinata), and slash (P. elliottii) pine cover types. The unadjusted average stand-level growth rates for survivor pines 1.0 in. diameter and greater at breast height were notably lower for all cover types during the latter survey in Georgia, while only the average unadjusted growth of shortleaf was substantially lower during this period in Alabama. However, when growth rates were adjusted with regression models to account for differences in initial stand structure (stand size class, stand density, site quality class, hardwood competition, and mortality) between the two survey periods, reductions in average adjusted basal area growth ranged from 3% to 31% during the later cycle in both states. The reductions were statistically significant in almost every case. The agents causing the growth differences were not identified, but it is unlikely that stand dynamics are responsible. The observational nature of the FIA dataset precludes further resolution of causal relationships. South. J. Appl. For. 15(2):73-79.

scholarly journals Does Raking Basal Duff Affect Tree Growth Rates or Mortality?

2010 ◽  
Vol 25 (4) ◽  
pp. 199-202 ◽  
Author(s):  
Erin Noonan-Wright ◽  
Sharon M. Hood ◽  
Danny R. Cluck
Keyword(s):  
Tree Growth ◽  
Growth Rates ◽  
Tree Mortality ◽  
Large Diameter ◽  
Mineral Soil ◽  
Basal Area ◽  
Basal Area Increment ◽  
National Forest ◽  
Jeffrey Pine ◽  
Pine Trees

Abstract Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure basal area increment. Results showed that raking basal duff and litter to mineral soil from the bole out to 60 cm had no effect on basal area increment or mortality for 5 years posttreatment. Results are pertinent to managers who question whether raking basal duff will decrease tree vigor or increase tree mortality of large and old ponderosa and Jeffrey pine trees in northern California.

scholarly journals Shrinkage of Scots pine wood as an effect of different tree growth rates, a comparison of regeneration methods

2018 ◽  
Vol 64 (No. 6) ◽  
pp. 271-278 ◽  
Author(s):  
Schönfelder Ondřej ◽  
Zeidler Aleš ◽  
Borůvka Vlastimil ◽  
Bílek Lukáš ◽  
Lexa Martin
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Growth Rates ◽  
Wood Properties ◽  
Forest Stands ◽  
Pine Wood ◽  
Clear Cutting ◽  
Regeneration Period ◽  
Site Characteristics ◽  
The Impact

The Scots pine (Pinus sylvestris Linnaeus) is one of the most important commercial tree species in Central Europe, yet we know very little about the variability of its wood properties. The aim of this study is to primarily analyse the impact of different tree growth rates and site characteristics on the shrinkage of Scots pine wood. The investigated forest stands are located at two sites of the Czech Republic that are characteristic for Scots pine silviculture. At each site, sample trees were selected from two stands representing two variants of the silvicultural treatment, i.e. a clear-cutting and shelterwood system with long regeneration period. Wood shrinkage in radial and tangential directions and volumetric shrinkage were determined in accordance with Czech standards. Lower values of shrinkage were found out in forest stands regenerated by the shelterwood method. The wood in the central part of the trunk shows lower shrinkage values than in the basal part in both stands. The unambiguous effect of the horizontal position in the trunk stem was demonstrated in forest stands regenerated by the clear-cutting method, whilst stands regenerated by the shelterwood method showed a more even distribution of shrinkage along the trunk width. Furthermore, it was found that the shrinkage of the Scots pine has a medium dependence on wood density.

scholarly journals Kuivenduse mõju rabamänniku arengule Järvselja Õppe- ja Katsemetskonna kuivendatud puistu näitel / Effect of drainage on the development of an oligotrophic bog Scots pine (P. sylvestris L.) stand in Järvselja

2013 ◽  
Vol 58 (1) ◽  
pp. 12-25
Author(s):  
Silver Sisask
Keyword(s):  
Scots Pine ◽  
Stand Structure ◽  
Measurement Data ◽  
Basal Area ◽  
Growth Conditions ◽  
Site Class ◽  
Growing Stock ◽  
Actual Change ◽  
Forest Drainage ◽  
Stand Characteristics

Abstract The effect of drainage in peatland forests has been studied in Estonia but research on bog pine (Pinus sylvestris L.) stands is lacking and mixed opinions on the expediency of amelioration in this site type are found. In order to obtain more information on the post drainage effects, measurements were conducted in a drained oligotrophic bog Scots pine stand (with a relatively thin peat layer) in Järvselja. Relationship between stand characteristics and distance from the drainage ditch was described and measurement data was compared with data that had been collected 59 years earlier in the same stand. Over time the stand structure and productivity had changed. Due to lengthy drainage, increase in several stand characteristics became evident: mean height 84% (8.60 ± 0.39 m), mean DBH 48% (6.55 ± 0.59 cm), basal area 59% (10.6 ± 3.4 m2 ha-1) and growing stock 179% (169 ± 32 m3 ha-1). Growth conditions had improved (site class improvement 1.8 units) and since earlier comparison data was from an already drained stand, actual change in stand characteristics and productivity compared to pre-drained state, has to be even greater. The studied stand is a good example of successful forest drainage in a bog pine forest and these results contribute to a better understanding of post drainage developments in these types of forests

scholarly journals Evaluating tree-to-tree competition during stand development in a relict Scots pine forest: how much does climate matter?

Trees ◽  
2021 ◽  
Author(s):  
Laura Marqués ◽  
J. Julio Camarero ◽  
Miguel A. Zavala ◽  
Markus Stoffel ◽  
Juan A. Ballesteros-Cánovas ◽  
...  
Keyword(s):  
Scots Pine ◽  
Stand Structure ◽  
Climatic Variability ◽  
Basal Area ◽  
Climatic Conditions ◽  
Climate Impacts ◽  
Stand Development ◽  
Relict Population ◽  
Competition Effects ◽  
Over Time

Abstract Key message Competitive interactions change over time and their influence on tree growth is intensified during drought events in marginal Scots pine populations. Abstract Competition is a key factor driving forest dynamics and stand structure during the course of stand development. Although the role of neighbourhood competition on stand dynamics has received increasing attention, the response of competition to environmental fluctuations and stand development remains poorly explored. We evaluated changes in competition during stand development in a dry-edge Scots pine relict population located in Central Spain. Typically, tree-to-tree interactions have been investigated through static competition measurements, which usually lack the temporal variation associated to natural forest development and environmental conditions. Here, we assessed how individual and neighbourhood components of competition evolved along a 35-year period, and we related competition dynamics to population structure and drought levels. On six plots, 508 trees were mapped and diameters at breast height (DBH) were measured. Two increment cores were taken from target trees to derive basal area increment (BAI), and neighbourhood was reconstructed back to 1980. Results provide insights into inter-annual variability in competition effects and their role on tree radial growth depending on climatic conditions. From the year 2005 onwards, both individual and neighbourhood components of competition showed a decoupled pattern over time. This effect was particularly pronounced during the extreme drought in 2012, in which the individual component decreased, whereas the neighbourhood component increased. In addition, climatic variability modulated the competition effects during stand development. This approach of evaluating competition dynamics proves to be promising for studying forest stand development and the influence of climate impacts on tree populations subjected to xeric conditions.

scholarly journals Neighbourhood and stand structure affect stemflow generation in a heterogeneous deciduous temperate forest

2019 ◽  
Author(s):  
Johanna C. Metzger ◽  
Jens Schumacher ◽  
Markus Lange ◽  
Anke Hildebrandt
Keyword(s):  
Fixed Effects ◽  
Stand Structure ◽  
Diversity Index ◽  
Temporal Stability ◽  
Basal Area ◽  
Beech Forest ◽  
Tree Size ◽  
Species Number ◽  
Forest Patches ◽  
Individual Tree

Abstract. Although stemflow oftentimes represents only a small portion of net precipitation in forests, it creates hot spots of water input that can affect subsurface stormflow dynamics. The distribution of stemflow over different trees is assumed to be temporally stable, yet often unknown. Therefore, it is essential to know the systematic factors driving stemflow patterns. Several drivers have been identified in the past, mainly related to tree traits. Less attention has yet been paid to tree neighbourhood interactions impacting stemflow generation and creating stand patches with enhanced or reduced stemflow. We recorded stemflow in 26 precipitation events on 65 trees, growing in 11 subplots (100 m² each), in a temperate mixed beech forest in the Hainich National Park, Germany. We used linear mixed effects models to investigate how traits of individual trees (tree size, tree species, number of neighbouring trees, their basal area, and their relative height) affect stemflow and how stemflow is affected by stand properties (stand, biomass and diversity metrics). As expected, stemflow increased with event and tree size. Stemflow was highly variable at both tree and subplot scale. Especially in large rainfall events (> 10 mm), tree/subplot ranking was almost identical between events, probably due to fully developed flow paths bringing out the full stemflow potential for each tree. Neighbourhood and stand structure were increasingly important with event size (15 % of fixed effects on the tree scale, ca. 65 % on the subplot scale for large events). Subplot scale stemflow was especially enhanced by a higher proportion of woody surface, expressed by a high number of trees, low leaf area and a large maximum tree size. Simpson’s diversity index contributed positively to stemflow yield in large events, probably by allowing more efficient space occupation. Also, our models suggest that neighbourhood impacts individual tree morphology, which may additionally increase stemflow in dense, species diverse neighbourhoods. Unexpectedly, rain shading within the canopy had little impact on stemflow spatial variation. Overall, we find a strong cross-scale temporal stability. Tree size and tree density were the main drivers, independently increasing stemflow, creating forest patches with strongly enhanced or reduced stemflow. Our results show that, besides tree metrics, also forest structure and potentially diversity affect stemflow patterns and associated potentially biogeochemical hotspots.

scholarly journals Neighbourhood and stand structure affect stemflow generation in a heterogeneous deciduous temperate forest

2019 ◽  
Vol 23 (11) ◽  
pp. 4433-4452 ◽  
Author(s):  
Johanna C. Metzger ◽  
Jens Schumacher ◽  
Markus Lange ◽  
Anke Hildebrandt
Keyword(s):  
Hot Spots ◽  
Fixed Effects ◽  
Stand Structure ◽  
Diversity Index ◽  
Temporal Stability ◽  
Basal Area ◽  
Beech Forest ◽  
Tree Size ◽  
Species Number ◽  
Individual Tree

Abstract. Although stemflow oftentimes only represents a small portion of net precipitation in forests, it creates hot spots of water input that can affect subsurface storm-flow dynamics. The distribution of stemflow over different trees is assumed to be temporally stable, yet often unknown. Therefore, it is essential to know the systematic factors driving stemflow patterns. Several drivers have been identified in the past, mainly related to tree traits. However, less attention has been paid to tree neighbourhood interactions impacting stemflow generation and creating stand patches with enhanced or reduced stemflow. We recorded stemflow during 26 precipitation events on 65 trees, growing in 11 subplots (100 m2 each), in a temperate mixed beech forest in the Hainich National Park, Germany. We used linear mixed effects models to investigate how traits of individual trees (tree size, tree species, number of neighbouring trees, their basal area and their relative height) affect stemflow and how stemflow is affected by stand properties (stand, biomass and diversity metrics). As expected, stemflow increased with event and tree size. Stemflow was highly variable at both the tree and subplot scale. Especially in large rainfall events (>10 mm), the tree/subplot ranking was almost identical between events, probably due to fully developed flow paths bringing out the full stemflow potential of each tree. Neighbourhood and stand structure were increasingly important with event size (15 % of fixed effects on the tree scale and ca. 65 % on the subplot scale for large events). Subplot-scale stemflow was especially enhanced by a higher proportion of woody surface, expressed by a high number of trees, low leaf area and a large maximum tree size. The Simpson diversity index contributed positively to stemflow yield for large events, probably by allowing more efficient space occupation. Furthermore, our models suggest that the neighbourhood impacts individual tree morphology, which may additionally increase stemflow in dense, species diverse neighbourhoods. Unexpectedly, rain shading within the canopy had little impact on the stemflow spatial variation. Overall, we find a strong cross-scale temporal stability. Tree size and tree density were the main drivers, independently increasing stemflow, creating forest patches with strongly enhanced or reduced stemflow. Our results show that, besides tree metrics, forest structure and tree diversity also affect stemflow patterns and the potentially associated biogeochemical hot spots.

Comparing individual-tree growth models using principles of stand growth for Norway spruce, Scots pine, and European beech

2015 ◽  
Vol 45 (8) ◽  
pp. 1006-1018 ◽  
Author(s):  
Sonja Vospernik ◽  
Robert A. Monserud ◽  
Hubert Sterba
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Tree Growth ◽  
Growth Models ◽  
Basal Area ◽  
European Beech ◽  
Growth And Yield ◽  
Individual Tree ◽  
Individual Tree Growth ◽  
Volume Increment

We examined the relationship between thinning intensity and volume increment predicted by four commonly used individual-tree growth models in Central Europe (i.e., BWIN, Moses, Prognaus, and Silva). We replicated conditions of older growth and yield experiments by selecting 34 young, dense plots of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and European beech (Fagus sylvatica L.). At these plots, we simulated growth, with mortality only, to obtain the maximum basal area. Maximum basal area was then decreased by 5% or 10% steps using thinning from below. Maximum density varied considerably between simulators; it was mostly in a reasonable range but partly exceeded the maximum basal area observed by the Austrian National Forest Inventory or the self-thinning line. In almost all cases, simulated volume increment was highest at maximum basal area and then decreased with decreasing basal area. Critical basal area, at which 95% of maximum volume increment can be achieved, ranged from 0.46 to 0.96. For all simulators, critical basal area was lower for the more shade-tolerant species. It increased with age, except for Norway spruce, when simulated with the BWIN model. Age, where mean annual increment culminated, compared well with yield tables.

Predicting tree crown ratio for unthinned and thinned Scots pine stands

1995 ◽  
Vol 25 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Jari Hynynen
Keyword(s):  
Scots Pine ◽  
Basal Area ◽  
Tree Height ◽  
Tree Crown ◽  
Thinning Intensity ◽  
Tree Diameter ◽  
Dominant Height ◽  
The Difference ◽  
Thinning Effect ◽  
Experimental Plots

A nonlinear model that yields logical predictions for tree crown ratio is presented. The model is based on data from permanent experimental plots located in even-aged Scots pine (Pinussylvestris L.) stands in southern and central Finland. Regressor variables in the model are stand dominant height, stand basal area, tree diameter, and tree height. The effect of thinning on tree crown ratio is modelled by incorporating a thinning response variable into the model. Thinning effect is dependent on thinning intensity and time elapsed from thinning, the latter of which is represented by the difference between current stand dominant height and dominant height at the time of thinning.

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