scholarly journals A contribution to the sessile oak site and beech site defining in central Serbia

2009 ◽  
pp. 143-158
Author(s):  
Milun Krstic ◽  
Bojana Cevrljakovic
Keyword(s):  
Tree Species ◽  
Local Heat ◽  
Mixed Stands ◽  
Mixed Forests ◽  
Altitudinal Belt ◽  
Sessile Oak ◽  
Heat Potential ◽  
Tree Number ◽  
Broadleaf Species ◽  
Weighted Values

The study was carried out in sessile oak forests and beech forests in the region central Serbia. The stands are classified as pure stands with the percentage of other species up to 10% per tree number, mixed forests of sessile oak with other species, and mixed forests of beech with other species, whose percentage does not exceed 50%. Altogether 257 stands were monitored - 202 beech stands and 55 sessile oak stands. By the applied method of defining the local heat potential (Lujic, 1960), modified by Ratknic et al. (2001) and Krstic (2004, 2008), which represents possibility of soil heating without vegetation, were determined. In this way, a scale of 162 possible combinations of local heat potential was obtained, which explains more precisely the dependence of beech stands and sessile oak stands on the topographic conditions. By applying the weighted values of the thermal co-ordinates of aspect and slope (E) for each altitudinal belt of 100 m, it was concluded that pure stands have the widest ecological range. Pure beech stands occur at the sites with 34 combinations of thermal co-ordinates E.V=4.6 to 8.12. Pure sessile oak stands occur at the sites with 12 combinations of thermal co-ordinates E.V=5.10 to 8.11. The percentage of mixed beech stands with other broadleaf species is the highest at the sites with the co-ordinate V=10-11 (at the altitudes between 700 and 900 m) is about 60 %. Mixed stands of sessile oak and beech are located on the terrains with combinations of thermal co-ordinates E.V=7.9 to 8.12. By using the local heat potential of a region, it can be identified which sites, i.e. which combinations of exposure, slope and altitude belong to the particular tree species. Consequently, a more reliable selection of tree species can be done for the bio-reclamation of barrens and other deforested terrains.

scholarly journals Accumulation of soil organic C and N in planted forests fostered by tree species mixture

2017 ◽  
Author(s):  
Yan Liu ◽  
Pifeng Lei ◽  
Wenhua Xiang ◽  
Wende Yan ◽  
Xiaoyong Chen
Keyword(s):  
Tree Species ◽  
Soil Depth ◽  
Pinus Massoniana ◽  
Stand Age ◽  
Cinnamomum Camphora ◽  
Mixed Stands ◽  
Pure Species ◽  
Mixed Forests ◽  
Organic C ◽  
The Impact

Abstract. With the increasing trend of converting monocultures into mixed forests, more and more studies were carried out to investigate the admixing effects on the tree growth and aboveground carbon storage. However, few studies have considered the impact of mixed forests on the belowground carbon sequestration, and changes of soil carbon and nitrogen stock as forest grows in particular. In this study, paired pure Pinus massoniana plantations, Cinnamomum camphora plantations and mixed Pinus massoniana-Cinnamomum camphora plantations at ages of 10, 24 and 45 years were selected to test whether the mixed plantations sequestrate more organic carbon (OC) and nitrogen (N) in soils and whether this admixing effect becomes more pronounced with stand ages. The results showed that tree species identity and composition as well as stand age significantly affect soil OC and N stock. The soil OC and N stocks were the highest in mixed Pinus-Cinnamomum stands compared to those in counterpart monocultures within the same age in the whole soil profiles or specific soil depth layers (0–10 cm, 10–20 cm and 20–30 cm) for most cases, followed by Cinnamomum stands, and the Pinus stands the lowest. And these positive admixing effects were mostly non-additive. Along chronosequence, the soil OC stock capacity peaked at 24-yr-old stand and maintained relatively stable thereafter. The admixing effects were also the highest at this stage. However, at topsoil layer, the admixing effects increased with stand ages in terms of soil OC stocks. When comparing mixed Pinus-Cinnamomum plantations with corresponding monocultures within the same age, the soil N stock in mixed stands was 8.30 %, 11.17 % and 31.45 % higher than the predicted mean value estimated from counterpart pure species plantations in 10-yr-old, 24-yr-old and 45-yr-old stands, respectively, suggesting these admixing effects were more pronounced along chronosequence.

scholarly journals Accumulation of soil organic C and N in planted forests fostered by tree species mixture

2017 ◽  
Vol 14 (17) ◽  
pp. 3937-3945 ◽  
Author(s):  
Yan Liu ◽  
Pifeng Lei ◽  
Wenhua Xiang ◽  
Wende Yan ◽  
Xiaoyong Chen
Keyword(s):  
Tree Species ◽  
Soil Depth ◽  
Pinus Massoniana ◽  
Stand Age ◽  
Cinnamomum Camphora ◽  
Mixed Stands ◽  
Pure Species ◽  
Mixed Forests ◽  
Organic C ◽  
The Impact

Abstract. With the increasing trend of converting monocultures into mixed forests, more and more studies have been carried out to investigate the admixing effects on tree growth and aboveground carbon storage. However, few studies have considered the impact of mixed forests on belowground carbon sequestration, particularly changes in soil carbon and nitrogen stocks as a forest grows. In this study, paired pure Pinus massoniana plantations, Cinnamomum camphora plantations and mixed Pinus massoniana–Cinnamomum camphora plantations at ages of 10, 24 and 45 years were selected to test whether the mixed plantations sequestrate more organic carbon (OC) and nitrogen (N) in soils and whether this admixing effect becomes more pronounced with stand ages. The results showed that tree species identification, composition and stand age significantly affected soil OC and N stocks. The soil OC and N stocks were the highest in mixed Pinus–Cinnamomum stands compared to those in counterpart monocultures with the same age in the whole soil profile or specific soil depth layers (0–10, 10–20 and 20–30 cm) for most cases, followed by Cinnamomum stands and Pinus stands with the lowest. These positive admixing effects were mostly nonadditive. Along the chronosequence, the soil OC stock peaked in the 24-year-old stand and was maintained as relatively stable thereafter. The admixing effects were also the highest at this stage. However, in the topsoil layer, the admixing effects increased with stand ages in terms of soil OC stocks. When comparing mixed Pinus–Cinnamomum plantations with corresponding monocultures within the same age, the soil N stock in mixed stands was 8.30, 11.17 and 31.45 % higher than the predicted mean value estimated from counterpart pure species plantations in 10-, 24- and 45-year-old stands, respectively. This suggests that these admixing effects were more pronounced along the chronosequence.

Contribution to the automation of the calculations involving the forest inventory with the aid of an office computer

1970 ◽  
Vol 20 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Tree Species ◽  
Forest Inventory ◽  
Basal Area ◽  
Annual Increment ◽  
Mixed Stands ◽  
Mean Values ◽  
Standing Trees ◽  
General Program ◽  
Magnetic Card ◽  
The Right

Contribution to the automation of the calculations involving  the forest inventory with the aid of an office computer - In this contribution an attempt was made to perform the  calculations involving the forest inventory by means of an office computer  Olivetti P203.     The general program (flowchart 1), identical for all tree species except  for the values of the different parameters, occupies the tracks A and B of a  magnetic card used with this computer. For each tree species one magnetic  card is required, while some supplementary cards are used for the  subroutines. The first subroutine (flowchart 1) enables us to preserve  temporarily the subtotals between two tree species (mixed stands) and so  called special or stand cards (SC). After the last tree species the totals  per ha are calculated and printed on the former, the average trees occuring  on the line below. Appendix 1 gives an example of a similar form resulting  from calculations involving a sampling in a mixed stand consisting of Oak  (code 11), Red oak (code 12), Japanese larch (code 24) and Beech (code 13).  On this form we find from the left to the right: the diameter class (m), the  number of trees per ha, the basal area (m2/ha), the current annual increment  of the basal area (m2/year/ha), current annual volume increment (m3/year/ha),  the volume (m3/ha) and the money value of the standing trees (Bfr/ha). On the  line before the last, the totals of the quantities mentioned above and of all  the tree species together are to be found. The last line gives a survey of  the average values dg, g, ig, ig, v and w.     Besides this form each stand or plot has a so-called 'stand card SC' on  wich the totals cited above as well as the area of the stand or the plot and  its code are stored. Similar 'stand card' may replace in many cases  completely the classical index cards; moreover they have the advantage that  the data can be entered directly into the computer so that further  calculations, classifications or tabling can be carried out by means of an  appropriate program or subroutine. The subroutine 2 (flowchart 2) illustrates  the use of similar cards for a series of stands or eventually a complete  forest, the real values of the different quantities above are calculated and  tabled (taking into account the area). At the same time the general totals  and the general mean values per ha, as well as the average trees are  calculated and printed. Appendix 2 represents a form resulting from such  calculations by means of subroutine 2.

scholarly journals Distribution of the timber quality attribute ‘knot surface’ in logs of Fagus sylvatica L. from pure and mixed forest stands

2021 ◽  
Author(s):  
Kirsten Höwler ◽  
Torsten Vor ◽  
Peter Schall ◽  
Peter Annighöfer ◽  
Dominik Seidel ◽  
...  
Keyword(s):  
Fagus Sylvatica ◽  
Mixed Forest ◽  
European Beech ◽  
Forest Stands ◽  
Species Identity ◽  
Mixed Stands ◽  
Mixed Forests ◽  
Climate Conditions ◽  
Timber Quality ◽  
Positive Effects

AbstractResearch on mixed forests has mostly focused on tree growth and productivity, or resistance and resilience in changing climate conditions, but only rarely on the effects of tree species mixing on timber quality. In particular, it is still unclear whether the numerous positive effects of mixed forests on productivity and stability come at the expense of timber quality. In this study, we used photographs of sawn boards from 90 European beech (Fagus sylvatica L.) trees of mixed and pure forest stands to analyze internal timber quality through the quality indicator knot surface that was quantitatively assessed using the software Datinf® Measure. We observed a decrease in knot surface with increasing distance from the pith as well as smaller values in the lower log sections. Regarding the influence of neighborhood species identity, we found only minor effects meaning that timber qualities in mixed stands of beech and Norway spruce (Picea abies (L.) H. Karst.) tended to be slightly worse compared to pure beech stands.

scholarly journals Object Oriented Classification for Mapping Mixed and Pure Forest Stands Using Very-High Resolution Imagery

2021 ◽  
Vol 13 (13) ◽  
pp. 2508
Author(s):  
Loredana Oreti ◽  
Diego Giuliarelli ◽  
Antonio Tomao ◽  
Anna Barbati
Keyword(s):  
High Resolution ◽  
Spatial Scales ◽  
Parametric Method ◽  
Mixed Forest ◽  
Mixed Stands ◽  
Mapping Unit ◽  
Mixed Forests ◽  
High Resolution Imagery ◽  
Very High Resolution Imagery ◽  
Very High

The importance of mixed forests is increasingly recognized on a scientific level, due to their greater productivity and efficiency in resource use, compared to pure stands. However, a reliable quantification of the actual spatial extent of mixed stands on a fine spatial scale is still lacking. Indeed, classification and mapping of mixed populations, especially with semi-automatic procedures, has been a challenging issue up to date. The main objective of this study is to evaluate the potential of Object-Based Image Analysis (OBIA) and Very-High-Resolution imagery (VHR) to detect and map mixed forests of broadleaves and coniferous trees with a Minimum Mapping Unit (MMU) of 500 m2. This study evaluates segmentation-based classification paired with non-parametric method K- nearest-neighbors (K-NN), trained with a dataset independent from the validation one. The forest area mapped as mixed forest canopies in the study area amounts to 11%, with an overall accuracy being equal to 85% and K of 0.78. Better levels of user and producer accuracies (85–93%) are reached in conifer and broadleaved dominated stands. The study findings demonstrate that the very high resolution images (0.20 m of spatial resolutions) can be reliably used to detect the fine-grained pattern of rare mixed forests, thus supporting the monitoring and management of forest resources also on fine spatial scales.

Impact of Deer Browsing on Regeneration in Mixed Stands in Southern New England

1995 ◽  
Vol 12 (3) ◽  
pp. 115-120 ◽  
Author(s):  
David B. Kittredge ◽  
P. Mark S. Ashton
Keyword(s):  
New England ◽  
Tree Species ◽  
Sugar Maple ◽  
Red Maple ◽  
White Pine ◽  
Mixed Stands ◽  
Tree Species Composition ◽  
Southern New England ◽  
Pine Seedlings ◽  
Species Specific

Abstract Browsing preferences by white-tailed deer were evaluated for 6 tree species in northeastern Connecticut. Deer density averaged 23/mile². Deer exhibited no species-specific preferences for seedlings greater than 19 in. For seedlings less than 19 in., hemlock and black birch were preferred. Red maple, sugar maple, and white pine seedlings were avoided. Red oak seedlings were neither preferred nor avoided. A much higher proportion of seedlings greater than 19.7 in. in height was browsed, regardless of species. Browsing preferences for species in the smaller seedling class, combined with a lack of preference for species in the larger class may result in future stands with less diverse tree species composition. Deer densities in excess of 23/mile² may be incompatible with regeneration of diverse forests in southern New England. North. J. Appl. For. 12(3):115-120.

Diversification of tree stands as a means to manage pests and diseases in boreal forests: myth or reality?

2006 ◽  
Vol 36 (2) ◽  
pp. 324-336 ◽  
Author(s):  
Julia Koricheva ◽  
Harri Vehviläinen ◽  
Janne Riihimäki ◽  
Kai Ruohomäki ◽  
Pekka Kaitaniemi ◽  
...  
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Boreal Forests ◽  
Tree Mortality ◽  
Tree Species Diversity ◽  
Mixed Stands ◽  
Tree Species Composition ◽  
Pests And Diseases ◽  
Pest Outbreaks ◽  
Disease Epidemics

Pure forest stands are widely believed to be more prone to pest outbreaks and disease epidemics than mixed stands, leading to recommendations of using stand diversification as a means of controlling forest pests and pathogens. We review the existing evidence concerning the effects of stand tree-species diversity on pests and pathogens in forests of the boreal zone. Experimental data from published studies provide no overall support for the hypothesis that diversification of tree stands can prevent pest outbreaks and disease epidemics. Although beneficial effects of tree-species diversity on stand vulnerability are observed in some cases, in terms of reductions in damage, these effects are not consistent over time and space and seem to depend more on tree-species composition than on tree-species diversity per se. In addition, while mixed stands may reduce the densities of some specialized herbivores, they may be more attractive to generalist herbivores. Given that generalist mammalian herbivores cause considerable tree mortality during the early stages of stand establishment in boreal forests, the net effect of stand diversification on stand damage is unlikely to be positive.

scholarly journals General regularities of height-diameter curves in Hungarian oak, sessile oak and Turkey oak high forests

2020 ◽  
Vol 21 (2) ◽  
pp. 71-82
Author(s):  
Roumen Petrin
Keyword(s):  
Tree Species ◽  
Oak Forests ◽  
Relative Height ◽  
Sessile Oak ◽  
Turkey Oak

The height-diameter curves of natural even-aged Hungarian oak, sessile oak and Turkey oak forests in the regions of Staro Oryahovo, Sherba, Tsonevo and Aytos Forestry Districts have been studied. In order to explore the shape of the curves and, in particular, their steepness, the steepness index SI of Douhovnikov (“the method of natural indicators”) was applied. The curves were divided into three groups according to it: flat curves, medium steep curves and steep curves. Both the traditional height-diameter curves and the corresponding relative curves of Tyurin were studied. Consideration of the traditional height-diameter curves gives a certain ground for investigating to-gether the height-diameter curves of Hungarian oak and sessile oak, disregarding the tree species. This inference was confirmed by comparing the relative height-diameter curves for Hungarian oak, sessile oak and Turkey oak with Tyurin’s uniform curve of relative heights. For these comparisons we used the Willcoxon test. A statistically significant great proximity in their shapes was found. As a uniform average curve of relative heights has been established for all tree species, this proximity indicates a possibility of creating a single fan of height-diameter curves for high Hungarian, sessile and Turkey oak.

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