scholarly journals Regeneration Dynamics Following the Formation of Understory Gaps in a Slovakian Beech Virgin Forest

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 585 ◽  
Author(s):  
Eike Feldmann ◽  
Jonas Glatthorn ◽  
Christian Ammer ◽  
Christoph Leuschner
Keyword(s):  
Diffuse Radiation ◽  
Height Growth ◽  
Tree Regeneration ◽  
Shoot Length ◽  
Virgin Forest ◽  
Length Growth ◽  
Spatial Differences ◽  
Closed Canopy ◽  
Sapling Density ◽  
Density And Biomass

The frequency and size of canopy gaps largely determine light transmission to lower canopy strata, controlling structuring processes in the understory. However, quantitative data from temperate virgin forests on the structure of regeneration in gaps and its dynamics over time are scarce. We studied the structure and height growth of tree regeneration by means of sapling density, shoot length growth and cumulative biomass in 17 understory gaps (29 to 931 m2 in size) in a Slovakian beech (Fagus sylvatica L.) virgin forest, and compared the gaps with the regeneration under closed-canopy conditions. Spatial differences in regeneration structure and growth rate within a gap and in the gap periphery were analyzed for their dependence on the relative intensities of direct and diffuse radiation (high vs. low). We tested the hypotheses that (i) the density and cumulative biomass of saplings are higher in gaps than in closed-canopy patches, (ii) the position in a gap influences the density and height growth of saplings, and (iii) height growth of saplings increases with gap size. Sapling density and biomass were significantly higher in understory gaps than under closed canopy. Density of saplings was positively affected by comparatively high direct, but low diffuse radiation, resulting in pronounced spatial differences. In contrast, sapling shoot length growth was positively affected by higher levels of diffuse radiation and also depended on sapling size, while direct radiation intensity was not influential. Conclusively, in this forest, regeneration likely becomes suppressed after a short period by lateral canopy expansion in small gaps (<100 m2), resulting in a heterogeneous understory structure. In larger gaps (≥100 m2) saplings may be capable even at low plant densities to fill the gap, often forming a cohort-like regeneration layer. Thus, gaps of different sizes imprint on the resulting canopy structure in different ways, enhancing spatial heterogeneity.

scholarly journals Structural diversity and regeneration patterns of the Norway spruce (Picea abies (L.) Karst) dominated virgin forest in NNR Zadná Poľana

Beskydy ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 127-134 ◽  
Author(s):  
M. Saniga ◽  
Miroslav Balanda ◽  
J. Pittner ◽  
S. Kucbel ◽  
P. Jaloviar
Keyword(s):  
Gini Index ◽  
Nature Reserve ◽  
Structural Diversity ◽  
Height Growth ◽  
Forest Stand ◽  
Virgin Forest ◽  
Old Growth Forest ◽  
Tree Generation ◽  
Evans Index ◽  
Structural Indices

The paper analyzes the structural diversity of the spruce dominated old-growth forest in National Nature Reserve (NNR) Zadná Poľana on the series of three permanent research plots (PRP) with the area of 0.5 ha each. The height and diameter diversity as well as the spatial distribution were expressed using standard structural indices (Füldner’s TH and TD index, Gini index, Clark-Evans index). Obtained results confirmed the low structural diversity regardless of the developmental stage of investigated forest. The extensive ungulate browsing retards the height growth of the subsequent tree generation and leads toward to the structural homogenization of the future forest stand.

The influence of the bamboo Yushania microphylla on regeneration of Abies densa in central Bhutan

1999 ◽  
Vol 29 (10) ◽  
pp. 1518-1527 ◽  
Author(s):  
G Gratzer ◽  
P B Rai ◽  
G Glatzel
Keyword(s):  
Forest Floor ◽  
Height Growth ◽  
Tree Regeneration ◽  
Average Height ◽  
Seedling Density ◽  
Tree Seedling ◽  
Term Survival ◽  
Light Levels ◽  
Gap Fraction ◽  
The Impact

To assess the impact of a dense understory of the bamboo Yushania microphylla Munro on tree regeneration in monospecific Abies densa Griff. stands of the central Bhutan Himalayas, the age-class distribution of fir regeneration, the microsite preferences, and height growth as well as the relationship between height of the bamboo, gap fraction, and tree seedling density were studied. Seedling densities were much lower on sites with bamboo. Recruitment was more or less continuous, and there was no indication of overall synchronized single-cohort regeneration in bamboo plots. On sites with bamboo understory, the light regime at the forest floor is strongly influenced by the height of the bamboo. A large portion of the variance of tree seedling density could be explained by the height of the bamboo. The mortality of fir seedlings is considerably reduced at elevated microsites. Fir establishment on the forest floor is restricted to sites where bamboo density is low and light levels are higher. On sites with dense, unbrowsed bamboo, light levels are too low for long-term survival of fir seedlings, resulting in a lack of suppressed regeneration with minimal height growth. Because of the absence of this fraction, the average height increment of fir seedlings is higher on sites with bamboo.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Coreopsis verticillata ‘Moonbeam’

2007 ◽  
Vol 25 (4) ◽  
pp. 229-233
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Maleic Hydrazide ◽  
Growth Index ◽  
Height Growth ◽  
Growth Retardant ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Quality Ratings ◽  
Quality Rating

Abstract This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

scholarly journals Interference to Hardwood Regeneration in Northeastern North America: The Effects of Raspberries (Rubus spp.) Following Clearcutting and Shelterwood Methods

2006 ◽  
Vol 23 (4) ◽  
pp. 288-296 ◽  
Author(s):  
Pablo J. Donoso ◽  
Ralph D. Nyland
Keyword(s):  
North America ◽  
Tree Regeneration ◽  
Rubus Idaeus ◽  
Tree Seedlings ◽  
Northeastern North America ◽  
Northern Hardwood ◽  
Hardwood Species ◽  
Closed Canopy ◽  
Shallow Soils ◽  
A Site

Abstract Rubus often becomes the most prominent vegetation within 2–3 years following heavy overstory disturbances at mesic sites within temperate forests of northeastern North America. This review draws together available literature about its dynamics and effects, focusing primarilyon raspberry (Rubus idaeus L.) and blackberry (Rubus allegheniensis Porter). It covers some key ecologic functions of raspberries related to nutrient leaching, microclimate near the ground, and organic matter decomposition. It also summarizes published information about the potentialinterference with desirable tree regeneration at northern hardwood sites within the region. The review concentrates on raspberry (Rubus spp.) dynamics and effects following clearcutting, shelterwood method, and other heavy overstory disturbances. Findings indicate that raspberries commonlydevelop into a dense cover after cutting and other overstory disturbances reduce the stocking of northern hardwood stands by 40% or more. Ecologically, they shade the ground, intercept and transpire water, and reduce the rate of litter decomposition and nutrient cycling, all of whichreduce leaching from a site. On poorly drained, droughty, and shallow soils, raspberries have reportedly delayed the development of hardwood regeneration. However, by 5–7 years, rapidly developing hardwood species have normally grown through the Rubus at most other sites, andthe emerging tree community has formed a closed canopy by 10–15 years. The presence of abundant, well-developed, and well-distributed advance tree regeneration ensures prompt restocking of new hardwoods, seems to minimize the potential for interference by raspberries, and precludes anyneed to release the tree seedlings from a raspberry cover. North. J. Appl. For. 23(4):288 –296.

Effect of light and humus on survival and height growth of ash (Fraxinus excelsior L.) seedlings

1998 ◽  
Vol 63 ◽  
Author(s):  
M. Tabari ◽  
M. Lust ◽  
J. Neirynck
Keyword(s):  
Survival Rate ◽  
Light Intensity ◽  
Growing Season ◽  
Height Growth ◽  
Fraxinus Excelsior ◽  
High Survival ◽  
Light Intensities ◽  
Stem Quality ◽  
Humus Type ◽  
Closed Canopy

In  1997, 300 3-month-old ash (Fraxinus excelsior L.) seedlings were removed out of the three    different humus types (100 seedlings from each humus type) in the  experimental forest of    Aelmoeseneie (University of Ghent) with a closed canopy, in north of  Belgium. Humus types were    described as active mull with pH of 5.3-6.5, acid mull with pH of 4.4-5.2  and moder mull with pH of    3.8-4.3. Seedlings were transplanted in plastic pots, filled by the  original soil, and placed under five    levels of light intensity (2.5, 10, 18,28 and 92%), inside and outside the  forest. Only with 92% light    intensity seedlings were watered as necessary to avoid any appreciable  water deficit.    The results after 1 growing season revealed that seedlings attained a very  high survival rate    (95.3%). Survival was the highest when seedlings grew under semi-closed  canopy (10, 18, and    28%) and also outside the forest at the 92% light intensity, compared with  those under closed    canopy (2.5%). It also confirmed that ash seedlings are shade tolerant, but  with little growth.    Height growth indicated an increasing growth response to nutrient  availability with increasing light    intensity. In fact, minimum height growth was observed in lower light  intensities (2.5 and 10%) and    the maximum value in higher light intensities (28 and 92%). Height growth  of ash seedlings    increased at humus types of active and acid mull, compared with moder  mull.    At the end of the first growing season, lack of differences in survival  rate and height growth,    produced under 18, 28 and 92% light intensity, revealed that training the  seedlings under semiclosed    canopy (18 and 26%) has a preference to those under relatively full  daylight (92%)    associated with watering. Therefore, the first year observations showed  that ash seedlings, either in    view of stem quality and growth or with regard to the facilities of  maintenance, are preferable to be    trained under intermediate light intensities (preferably 28%), at the high  nutritional humus (active    and acid mull).

Crown architecture of Larix laricina saplings: sylleptic branching on the main stem

1985 ◽  
Vol 63 (7) ◽  
pp. 1296-1302 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Growth Increment ◽  
Height Growth ◽  
Shoot Length ◽  
Larix Laricina ◽  
Crown Architecture ◽  
Branching Patterns ◽  
Architectural Model ◽  
Long Shoots ◽  
Lateral Branches ◽  
Architectural Characteristics

Sylleptic branching occurred on the current (1983) height-growth increment in 44% of Larix laricina (Du Roi) K. Koch (tamarack) saplings sampled from a natural population near Fredericton, N.B. Although variable, the occurrence and amount of syllepsis tended to increase with parental shoot length. Sylleptic shoots were generally located on the proximal halves of parental shoots. In most cases, the proximally and distally situated sylleptic shoots were somewhat shorter than those in between. The lengths of terminal shoots arising from sylleptic shoots were significantly correlated with parental shoot length, current tree leader length, and location of the branch on its parental shoot. The lengths and elevation angles of terminal extensions from sylleptic shoots tended to be greater than those from nonsylleptic (proleptic) lateral long shoots borne in the same region of the height-growth increment. Architectural characteristics of the extensions resembled those of the more distal proleptic shoots, which develop into major branches. Thus, an additional complement of major lateral branches appeared to be developing where syllepsis occurred. Quantitative relationships depicting sylleptic branching patterns were incorporated into a previous architectural model and simulations of crown architecture which included syllepsis were obtained.

scholarly journals The effect of nitrogen on growth and architecture of Fraxinus pennsylvanica 'Patmore' (green ash) in Field-grow containers at two sites in Manitoba, Canada

1996 ◽  
Vol 76 (4) ◽  
pp. 825-833 ◽  
Author(s):  
W. R. Remphrey ◽  
C. G. Davidson
Keyword(s):  
Growth And Development ◽  
Growth Increment ◽  
Height Growth ◽  
Shoot Length ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Growing Seasons ◽  
Lateral Shoots ◽  
N Treatment ◽  
Four Levels

Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern. 'Patmore' green ash was established at two sites in southern Manitoba. Four levels of N fertilizer (4.5–400 ppm) were applied during two growing seasons. Growth and development of the trees was dependent on the site and local environmental conditions. At Morden, the annual height growth increment was greater with lower levels of N applications and declined at higher levels, while at Winnipeg higher levels resulted in greater growth. Stem diameter changes followed a similar pattern. The numbers of lateral shoots per parent shoot were only weakly affected by N treatment and any differences appeared to be an indirect effect of parental shoot length. The Field-grow containers at the Winnipeg site were installed in crass-sod which penetrated the containers and appeared to result in competition for N resources. The Morden site was kept cultivated and thus there was no such competition. At Morden, it is possible that wicking from the surrounding soil may have moved excessive salts into the containers resulting in high conductivity values and toxicity. Key words: Field-grow, biomass, roots, architecture, fertilization, Fraxinus pennsylvanica

scholarly journals Abschätzung des Einflusses von Verbiss durch wildlebende Huftiere auf die Baumverjüngung

2019 ◽  
Vol 170 (3) ◽  
pp. 125-134
Author(s):  
Andrea D. Kupferschmid ◽  
Peter Brang ◽  
Harald Bugmann
Keyword(s):  
Relative Number ◽  
Height Growth ◽  
Tree Regeneration ◽  
Height Increment ◽  
Wild Ungulates ◽  
Ungulate Browsing ◽  
The Impact

Assessment of the impact of ungulate browsing on tree regeneration Browsing percentage is an objective and reproducible measure of the frequency of browsing by wild ungulates on tree regeneration. However, this relative number of browsed terminal shoots accounts for little of the effective long-term influence of browsing on tree regeneration. Apart from browsing percentage, the following four factors are important for estimating the influence of browsing: the density of tree regeneration, the within-tree browsing intensity, the height growth of the tree regeneration (and thus the time needed to grow out of the reach of browsers and the browsing-induced loss of height increment), and the mortality induced by browsing. At least the first three of these factors can be obtained easily and should thus be included in future browsing inventories.

Effects of cutting intensity, deer browsing, and liming on Allegheny hardwood tree regeneration

1979 ◽  
Vol 9 (3) ◽  
pp. 362-368
Author(s):  
J. R. McClenahen ◽  
R. J. Hutnik
Keyword(s):  
Height Growth ◽  
Tree Regeneration ◽  
Clear Cut ◽  
Clear Cutting ◽  
Growing Seasons ◽  
Hardwood Tree ◽  
Cutting Intensity ◽  
Nonsignificant Effect ◽  
Growth Of Seedlings ◽  
Survival Of Seedlings

Survival, height growth, and abundance of Prunusserotina Ehrh. and other species of tree reproduction were studied during two growing seasons after the trees were cut to residual basal areas of 0 (clear-cut), 16 (partial cut), and 28 (uncut) m2/ha. Portions of each cutting treatment were fenced to exclude deer and (or) amended with 0.91 t/ha of dolomitic limestone. Survival of advance P. serotina seedlings was best among initially older, taller stems. Mortality among 1st-year P. serotina seedlings was higher on clear-cut and uncut plots than on partially cut plots, but cutting had no effect on survival of seedlings older than 2 years. Acersaccharum Marsh, survival was poorest on clear-cuttings. The intermediate level of cutting initially favored a greater abundance of more species than either clear-cutting or no cutting. Rates of height growth of dominant P. serotina seedlings were greatest on clear-cuttings, less on partially cut plots, and lowest in uncut plots. Browsing by deer had a large but statistically nonsignificant effect on height of dominant reproduction after 6 years. Slash generally reduced abundance but enhanced height growth of seedlings. Overall, partial (shelterwood) cutting appeared to be a viable alternative to clear-cutting as a means for regenerating even-aged Allegheny hardwood stands.

Effects of soil acidity and phosphorus on the growth and nodule development of black alder

1982 ◽  
Vol 12 (3) ◽  
pp. 576-581 ◽  
Author(s):  
John R. Seiler ◽  
L. H. McCormick
Keyword(s):  
Soil Acidity ◽  
Response Pattern ◽  
Height Growth ◽  
Shoot Length ◽  
Nodule Development ◽  
Black Alder ◽  
Mine Spoils ◽  
Acid Mine ◽  
Phosphorus Levels

Nodulated and nonnodulated black alder, Alnusglutinosa (L.) Gaertn., seedlings were grown in two acid mine spoils amended with five rates of lime (0.0, 1.0, 2.0, 4.0, and 8.0 g/kg of soil size particles) and three rates of phosphorus (0.0, 25.0, and 50.0 mg/kg of soil size particles). Height growth of nodulated seedlings was enhanced by lime and phosphorus. A significant lime X phosphorus interaction occurred for height growth of nodulated seedlings in both spoils: response to liming increased as the level of phosphorus was increased. Best height growth occurred at the highest lime and phosphorus levels. Nonnodulated seedlings failed to respond to either of the spoil amendments. Nodule weights of seedlings also were affected by lime and phosphorus and followed the same response pattern as shoot length.

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