An attempt to explain the distribution of the tree species composing the riparian forests of Lake Duparquet, southern boreal region of Quebec, Canada

2000 ◽  
Vol 77 (12) ◽  
pp. 1744-1755 ◽  
Author(s):  
Bernhard Denneler ◽  
Yves Bergeron ◽  
Yves Bégin
Keyword(s):  
Tree Species ◽  
Elevation Gradient ◽  
Great Part ◽  
Morphological Differentiation ◽  
Basal Area ◽  
Stepwise Logistic Regression ◽  
Minor Importance ◽  
Rock Outcrops ◽  
Data Set ◽  
Boreal Region

The objective of this study was to evaluate the most important environmental factors determining the distribution of tree species within the riparian zone of Lake Duparquet, located in the southern boreal region of Quebec, Canada. Occurrence and relative basal area of 10 species were recorded within an altitudinal range of 200 cm above mean water level along 95 transects. Stepwise logistic regression and canonical correspondence analyses were performed on the overall data set as well as separately for the five geomorphological shore types distinguished (depositional flats, floodplains, beaches, terraces, and rock outcrops). The elevation gradient, representing seasonal floodings, is the main factor determining the distribution of the species. The differences between the geomorphological shore types with respect to composition and arrangement of the arborescent vegetation along the elevation gradient are at least partially explained by surficial substratum, topography, aspect, and fire. Exposure to wave activity seems to be of minor importance only. However, since they are the driving force of erosion and sedimentation, the waves are to a great part responsible for the morphological differentiation of the shoreline. The distribution of the tree species along a characteristic physiographic cross-section is illustrated for each geomorphological shore type.

scholarly journals Stand Structure, Regeneration Status and Distribution Patterns of Six Important Tree Species along Altitudinal Gradients at the Kilum-Ijim Forest Reserve, Cameroon

2020 ◽  
pp. 41-57
Author(s):  
Franklin Bantar Nworo ◽  
Njoh Roland Ndah ◽  
Egbe Enow Andrew
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Anthropogenic Activities ◽  
Elevation Gradient ◽  
Basal Area ◽  
Tree Height ◽  
Distribution Patterns ◽  
Forest Reserve ◽  
Altitudinal Gradients ◽  
Regeneration Status

Tropical montane forests are considered to be one of the most species diverse ecosystems. These areas pose specific edaphic and environmental characteristics which enable these areas to harbour wide varieties of organisms. Some of these organisms are threatened and others are endemic to the area. The quest for food and other resources has resulted to indiscriminate exploitation of these montane forest. This study aimed to investigate the stand structure, distribution patterns and regeneration status of six tree species (Nuxia congesta, Pittosporum mannii, Podocarpu slatifolius, Prunus africana, Schefflera abyssinica and Syzygium guineense) along altitudinal gradients in the Kilum-Ijim Forest Reserve, Cameroon. A total of six study plots of one hectare (100 x100 m) each were laid across a 120 m elevation gradient. Two plots were established at each altitudinal gradient with elevations 2377 m, 2437 m and 2497 m. Measurements were taken for tree height, diameter at breast height (DBH 1.3 m) for the tree and poles. The digital Vernier callipers were used to measure collar diameters of seedlings and saplings. The highest tree density of 385 stems/ha was recorded for N. congesta at altitude 2497 m while the least was 20 stems/ha for S. abyssinica at altitude 2377m. The highest seedling density was 1563 stems/ha recorded for P. mannii at altitude 2377m and the least was noted for S. abyssinica at all the three altitudinal gradients.  Nuxia congesta had the highest basal area of 8809.23m2/ha at altitude 2437 m and the least of 74.82m2/ha for P. latifolius at altitude 2437 m.  The highest IVI occurred in N. congesta (131.91) was recorded at altitude 2377 m and the least (24.91) occurred in P. latifolius at altitude 2437 m. The spatial distributions of studied tree species were generally clumped and irregular. The regenerations of species were generally poor, though fair regenerations were noticed for N. congesta and P. mannii. The results showed that the six tree species were highly disturbed by anthropogenic activities. It is therefore imperative to develop and implement effective conservation measures to sustain the biodiversity of this reserve.

Floristic Variation of Tree Communities and Their Association with Soil Properties in Pulau Jerejak, Penang, Peninsular Malaysia

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi
Keyword(s):  
Tree Species ◽  
Diversity Index ◽  
Basal Area ◽  
Peninsular Malaysia ◽  
Importance Value ◽  
Conservation Action ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Tree Communities ◽  
Floristic Variation

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

Live tree species basal area of the contiguous United States (2000-2009)

2013 ◽  
Author(s):  
Barry T. Wilson ◽  
Andrew J. Lister ◽  
Rachel I. Riemann ◽  
Douglas M. Griffith
Keyword(s):  
United States ◽  
Tree Species ◽  
Basal Area ◽  
Live Tree

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 Soil carbon and nutrient stocks under Scots pine plantations in comparison to European beech forests: a paired-plot study across forests with different management history and precipitation regimes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Marco Diers ◽  
Robert Weigel ◽  
Heike Culmsee ◽  
Christoph Leuschner
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
European Beech ◽  
Organic Layer ◽  
Species Identity ◽  
Data Set ◽  
Nutrient Pools ◽  
Total N ◽  
Precipitation Regimes ◽  
Pine Stands

Abstract Background Organic carbon stored in forest soils (SOC) represents an important element of the global C cycle. It is thought that the C storage capacity of the stable pool can be enhanced by increasing forest productivity, but empirical evidence in support of this assumption from forests differing in tree species and productivity, while stocking on similar substrate, is scarce. Methods We determined the stocks of SOC and macro-nutrients (nitrogen, phosphorus, calcium, potassium and magnesium) in nine paired European beech/Scots pine stands on similar Pleistocene sandy substrates across a precipitation gradient (560–820 mm∙yr− 1) in northern Germany and explored the influence of tree species, forest history, climate, and soil pH on SOC and nutrient pools. Results While the organic layer stored on average about 80% more C under pine than beech, the pools of SOC and total N in the total profile (organic layer plus mineral soil measured to 60 cm and extrapolated to 100 cm) were greater under pine by about 40% and 20%, respectively. This contrasts with a higher annual production of foliar litter and a much higher fine root biomass in beech stands, indicating that soil C sequestration is unrelated to the production of leaf litter and fine roots in these stands on Pleistocene sandy soils. The pools of available P and basic cations tended to be higher under beech. Neither precipitation nor temperature influenced the SOC pool, whereas tree species was a key driver. An extended data set (which included additional pine stands established more recently on former agricultural soil) revealed that, besides tree species identity, forest continuity is an important factor determining the SOC and nutrient pools of these stands. Conclusion We conclude that tree species identity can exert a considerable influence on the stocks of SOC and macronutrients, which may be unrelated to productivity but closely linked to species-specific forest management histories, thus masking weaker climate and soil chemistry effects on pool sizes.

scholarly journals Determinants of prepaid systems of healthcare financing: a worldwide country-level perspective

2021 ◽  
Author(s):  
Andrea M. Leiter ◽  
Engelbert Theurl
Keyword(s):  
Health Care ◽  
Panel Data ◽  
Health Care Financing ◽  
Value Added ◽  
The Elderly ◽  
Dynamic Panel Data ◽  
Individual Characteristics ◽  
Minor Importance ◽  
Data Set ◽  
Country Level

AbstractIn this paper we examine determinants of prepaid modes of health care financing in a worldwide cross-country perspective. We use three different indicators to capture the role of prepaid modes in health care financing: (i) the share of total prepaid financing as percent of total current health expenditures, (ii) the share of voluntary prepaid financing as percent of total prepaid financing, and (iii) the share of compulsory health insurance as percent of total compulsory prepaid financing. In the econometric analysis, we refer to a panel data set comprising 154 countries and covering the time period 2000–2015. We apply a static as well as a dynamic panel data model. We find that the current structure of prepaid financing is significantly determined by its different forms in the past. The significant influence of GDP per capita, governmental revenues, the agricultural value added, development assistance for health, degree of urbanization and regulatory quality varies depending on the financing structure we look at. The share of the elderly and the education level are only of minor importance for explaining the variation in a country’s share of prepaid health care financing. The importance of the mentioned variables as determinants for prepaid health care financing also varies depending on the countries’ socio-economic development. From our analysis we conclude that more detailed information on indicators which reflect the distribution of individual characteristics (such as income, family size and structure and health risks) within a country’s population would be needed to gain deeper insight into the decisive determinants for prepaid health care financing.

Tekstura drzewostanów naturalnych w polskich parkach narodowych na tle teorii dynamiki lasu

2021 ◽  
Author(s):  
Leszek Bartkowicz ◽  
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Basal Area ◽  
Site Conditions ◽  
Gap Dynamics ◽  
Old Growth ◽  
Mosaic Pattern ◽  
Spruce Forests ◽  
Old Growth Forest ◽  
Patch Mosaic

The aim of the study was to compare a patch-mosaic pattern in the old-growth forest stands developed in various climate and soil conditions occurring in different regions of Poland. Based on the assumption, that the patch-mosaic pattern in the forest reflect the dynamic processes taking place in it, and that each type of forest ecosystem is characterized by a specific regime of natural disturbances, the following hypotheses were formulated: (i) the patches with a complex structure in stands composed of latesuccessional, shade-tolerant tree species are more common than those composed of early-successional, light-demanding ones, (ii) the patch-mosaic pattern is more heterogeneous in optimal forest site conditions than in extreme ones, (iii) in similar site conditions differentiation of the stand structure in distinguished patches is determined by the successional status of the tree species forming a given patch, (iv) the successional trends leading to changes of species composition foster diversification of the patch structure, (v) differentiation of the stand structure is negatively related to their local basal area, especially in patches with a high level of its accumulation. Among the best-preserved old-growth forest remaining under strict protection in the Polish national parks, nineteen research plots of around 10 ha each were selected. In each plot, a grid (50 × 50 m) of circular sample subplots (with radius 12,62 m) was established. In the sample subplots, species and diameter at breast height of living trees (dbh ≥ 7 cm) were determined. Subsequently, for each sample subplot, several numerical indices were calculated: local basal area (G), dbh structure differentiation index (STR), climax index (CL) and successional index (MS). Statistical tests of Kruskal- Wallis, Levene and Generalized Additive Models (GAM) were used to verify the hypotheses. All examined forests were characterized by a large diversity of stand structure. A particularly high frequency of highly differentiated patches (STR > 0,6) was recorded in the alder swamp forest. The patch mosaic in the examined plots was different – apart from the stands with a strongly pronounced mosaic character (especially subalpine spruce forests), there were also stands with high spatial homogeneity (mainly fir forests). The stand structure in the distinguished patches was generally poorly related to the other studied features. Consequently, all hypotheses were rejected. These results indicate a very complex, mixed pattern of forest natural dynamics regardless of site conditions. In beech forests and lowland multi-species deciduous forests, small-scale disturbances of the gap dynamics type dominate, which are overlapped with less frequent medium-scale disturbances. In more difficult site conditions, large-scale catastrophic disturbances, which occasionally appear in communities formed under the influence of gap dynamics (mainly spruce forests) or cohort dynamics (mainly pine forests), gain importance.

Structure and Regeneration of Sal (Shorea robusta Gaertn. f.) Forests in Shiwalik Region of Kumaun Himalaya, India

2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Tree Canopy ◽  
Canopy Density ◽  
Kumaun Himalaya ◽  
Shorea Robusta ◽  
Canopy Trees ◽  
Dense Forest ◽  
Open Forest ◽  
Sal Forest

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.

scholarly journals Tree Diversity and Their Regeneration in the Sacred Groves of Virajpet, Central Western Ghats, India

2016 ◽  
Vol 8 (3) ◽  
pp. 360-369
Author(s):  
Devi A.G. PRASAD ◽  
Shwetha BHARATHI
Keyword(s):  
Tree Species ◽  
Western Ghats ◽  
Basal Area ◽  
Sacred Groves ◽  
Forest Patches ◽  
Tree Species Composition ◽  
Rich Diversity ◽  
Central Western Ghats ◽  
Undisturbed Forest ◽  
The Rich

Sacred groves are one of the finest examples of informal way of conserving the forest wealth. Baseline data collection of their diversity, distribution and regeneration capacity becomes necessary for the management and conservation of these undisturbed forest patches. In this context, the present investigation was carried out using random quadrat method in the sacred groves of Virajpet, Karnataka, India. A total of 132 tree species belonging to 113 genera and 45 families were identified within five sacred groves. Higher basal area (51.73-85.65 m2/ha) and tree density (453.33-515.9 individuals/ha) were observed as compared to other forests of Western Ghats region. The present investigation has revealed a healthy regeneration of tree species. Seedling and sapling composition differed to some extent from the mature tree species composition which could be used in predicting the future possibilities. Protection and conservation of such sacred groves should be of interest, for better regeneration of the rich diversity they harbour.

Ray fractions and carbohydrate dynamics of tree species along a 2750 m elevation gradient indicate climate response, not spatial storage limitation

2020 ◽  
Vol 225 (6) ◽  
pp. 2314-2330
Author(s):  
Jessie M. Godfrey ◽  
Jason Riggio ◽  
Jessica Orozco ◽  
Paula Guzmán‐Delgado ◽  
Alana R. O. Chin ◽  
...  
Keyword(s):  
Tree Species ◽  
Elevation Gradient ◽  
Climate Response ◽  
Carbohydrate Dynamics
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