Small-scale disturbance in a northern hardwoods forest: effects on tree species abundance and distribution

1993 ◽  
Vol 23 (7) ◽  
pp. 1347-1360 ◽  
Author(s):  
Jan W. McClure ◽  
Thomas D. Lee
Keyword(s):  
Tree Species ◽  
Species Abundance ◽  
Root Competition ◽  
Northern Hardwoods ◽  
Soil Conditions ◽  
Small Scale ◽  
Gap Size ◽  
Old Growth Forest ◽  
Tolerant Species ◽  
Shade Tolerant Species

Sampling of 24-, 34-, and 44-year-old patch cuts (324–2400 m2) in the Bartlett Experimental Forest, New Hampshire, was undertaken to assess the effect of gap size and location within a gap on tree species abundance (relative basal area and relative density). Shade-tolerant species, especially eastern hemlock (Tsugacanadensis (L.) Carr.) and American beech (Fagusgrandifolia Ehrh.), were relatively more abundant in small gaps and gap edges and generally decreased with increasing gap size. Shade-intolerant species, including paper birch (Betulapapyrifera Marsh.) and pin cherry (Prunuspensylvanica L.f.), were relatively more abundant in large gaps and gap centers and increased with increasing gap size. Intermediately shade-tolerant species, especially yellow birch (Betulaalleghaniensis Britt.) and red maple (Acerrubrum L.), were relatively more abundant in gap centers. Striped maple (Acerpensylvanicum L.) was relatively more abundant in gap edges. Many of these relationships were complex due to interactions with gap age and slope. Sugar maple (Acersaccharum Marsh.) relative abundance was not associated with gap size or location within a gap. Analyses isolating irradiance as a factor influencing species composition were inconclusive. Instead, other effects of gap disturbance and characteristics associated with different locations in the gap, such as soil conditions and root competition, may play an important role in the gap dynamics of this northern hardwoods forest. Gap age had a strong effect on species relative abundances and these patterns reflected typical successional sequences in northern hardwood forests. The gap disturbances increased species richness and diversity in this forest. Gaps contained species not present in the old-growth forest, and the species compositional variations among different gap sizes suggest that a forest with a range of gap sizes will have high diversity. Competitive exclusion appeared to be prevented by the gap disturbances, a likely consequence of the release of previously unavailable resources.

scholarly journals HEIGHT STRUCTURE AND SPATIAL PATTERN OF FIVE TROPICAL TREE SPECIES IN TWO SEASONAL SEMIDECIDUOUS FOREST FRAGMENTS WITH DIFFERENT CONSERVATION HISTORIES

2016 ◽  
Vol 40 (3) ◽  
pp. 395-405 ◽  
Author(s):  
Diego Resende Rodrigues ◽  
Yves Rafael Bovolenta ◽  
José Antonio Pimenta ◽  
Edmilson Bianchini
Keyword(s):  
Spatial Pattern ◽  
Tree Species ◽  
Forest Fragments ◽  
Semideciduous Forest ◽  
Old Growth Forest ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
The Stability ◽  
Height Data ◽  
Seasonal Semideciduous Forest

ABSTRACT Anthropogenic disturbances in forests modify survival conditions and development of plants, which has direct effect on the height and spatial structure of tree populations. This study aimed to compare the height structure and spatial pattern of five tree species in two distinct fragments of seasonal semideciduous forest with different histories of conservation. We studied shade-intolerant (Astronium graveolens Jacq., Gallesia integrifolia (Spreng.) Harms) and shade-tolerant species (Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl., Euterpe edulis Mart. and Holocalyx balansae Micheli). Sixty plots of 100 m2 (10 m x 10 m) were allocated, being 30 contiguous plots in each fragment. All individuals of five species were marked, assessed for total height data and mapped using Cartesian coordinates. We observed differences in height structure between fragments. All populations had a random spatial pattern, except to H. balansae in the less conserved fragment and E. edulis in the conserved fragment that showed a clumped spatial pattern. There were evidences of forest regeneration due to the establishment of shade-tolerant species in less conserved fragment and coexistence of functional groups in both fragments. The height structure and spatial pattern analyses indicating that anthropogenic exploitation changed the environment and population structure in the less conserved area when compared to conserved area. The anthropic exploitation was ceased few years ago, so it is expected that the less conserved fragment reach the stability of an old-growth forest.

Canopy tree growth responses following selection harvest in seven species varying in shade tolerance

2009 ◽  
Vol 39 (2) ◽  
pp. 430-440 ◽  
Author(s):  
Trevor A. Jones ◽  
Grant M. Domke ◽  
Sean C. Thomas
Keyword(s):  
Community Dynamics ◽  
Time Lag ◽  
Species Abundance ◽  
Basal Area ◽  
Maximum Growth ◽  
Forest Community ◽  
Growth Responses ◽  
Canopy Tree ◽  
Tolerant Species ◽  
Shade Tolerant Species

We used tree ring measurements to investigate the temporal response of basal area increment (BAI) of canopy trees following selection harvests by sampling across a chronosequence of stands with known harvest dates in tolerant hardwood (Great Lakes – St. Lawrence) stands in central Ontario. Seven tree species of various shade tolerances ranged widely in their responses to reduced competition. The more shade-tolerant species responded more positively: shade-tolerant species showed an average increase in BAI of 35% 4–15 years postharvest compared with 16% for mid-tolerant species and –7.5% for intolerant species. All species showed a time-lag in postharvest growth responses, with maximum growth responses occurring between 3 and 15 years postharvest. Tree size was the most important factor determining the magnitude of BAI response, with smaller trees consistently responding more than larger trees. We suggest that higher growth responses to selection harvests among shade-tolerant species may contribute to declines in mid-tolerant species abundance in selection-managed stands. More broadly, interspecific variability in canopy tree responses to forest disturbance appears to follow patterns distinct from seedling and sapling responses, with important implications to forest community dynamics in both managed and unmanaged forests.

scholarly journals Floristic Change at the Drought Limit of European Beech (Fagus sylvatica L.) to Downy Oak (Quercus pubescens) Forest in the Temperate Climate of Central Europe

2017 ◽  
Vol 45 (2) ◽  
pp. 646-654 ◽  
Author(s):  
Albert REIF ◽  
Fotios XYSTRAKIS ◽  
Stefanie GÄRTNER ◽  
Uwe SAYER
Keyword(s):  
Fagus Sylvatica ◽  
Tree Species ◽  
European Beech ◽  
Temperate Climate ◽  
Soil Conditions ◽  
Quercus Pubescens ◽  
Drought Tolerant ◽  
Tolerant Species ◽  
Fagus Sylvatica L ◽  
Shallow Soils

An increase in drought could cause shifts in species composition and vegetation structure. In forests it limits the occurrence of drought sensitive tree species which become replaced by drought tolerant tree species and forest communities. Under temperate macroclimatic conditions, European beech (Fagus sylvatica L.) naturally dominates the forested landscape, except on extremely shallow soil in combination with high irradiation. On these sites beech reaches its drought limit, and is replaced by forests dominated by species like downy Oak (Quercus pubescens s.l.) and English Oak (Quercus petraea L). Phytosociological and ecological data were collected in the transition (ecotone) between European beach stands and stands of more drought tolerant species in order to quantify the drought intensity threshold, above which beech is replaced by drought tolerant species. It was shown that favourable topographic and soil conditions partially compensated the unsuitable climatic conditions for beech. The ecotone between these forest types was found to be characterized by shallow soils with an available soil water storage capacity of 73 l/m² or less, and an irradiation intensity of 6000 MJ/m2 or more during the growing season. This indicates that under conditions of climate change beech would naturally still remain the dominant tree species on the majority of central European forest sites.

Effects of suppression and release on sapling growth for 11 tree species of northern, interior British Columbia

2000 ◽  
Vol 30 (10) ◽  
pp. 1571-1580 ◽  
Author(s):  
Elaine F Wright ◽  
Charles D Canham ◽  
K D Coates
Keyword(s):  
British Columbia ◽  
Populus Tremuloides ◽  
Tree Species ◽  
Light Level ◽  
Long Term Effects ◽  
Partial Cutting ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
Sapling Growth ◽  
Over Time

Saplings of canopy tree species frequently undergo alternating periods of suppression and release before reaching canopy size. In this study, we document the effects of periods of suppression and release on current responses to variation in light by saplings of the 11 major tree species of northwestern, interior British Columbia. We were specifically interested in the degree to which increasing length of suppression had long-term effects on subsequent response to release in gaps or following partial cutting, and the degree to which the effects of suppression were ameliorated with time following release. At least some saplings of all 11 species had undergone alternating periods of suppression and release. The most shade-tolerant species generally did not show either a decline in growth over time during suppression or a gradual increase in growth at a given light level over time during release. The least shade-tolerant species exhibited significant declines in growth rate during suppression; however, in all of the species except trembling aspen (Populus tremuloides Michx.), the effects of suppression disappeared over time during release. Failure to account for the effects of past suppression and release leads to significant overestimates of the initial responses of shade-intolerant species to release. Our results suggest that competitive balances between species shift substantially over time as a result of growth history and that these shifts have significant effects on successional patterns.

scholarly journals Effect of Gap Size And Elevation On The Regeneration And Coexistence of Three Tree Species In A Subalpine Coniferous Forest

2021 ◽  
Author(s):  
Wangya Han ◽  
Li Chen ◽  
G. Geoff Wang ◽  
Dan Liu ◽  
Guohua Liu
Keyword(s):  
Community Assembly ◽  
Tree Species ◽  
Species Coexistence ◽  
Elevation Gradient ◽  
Coniferous Forest ◽  
Photon Flux ◽  
Gap Size ◽  
Stem Size ◽  
Subalpine Coniferous Forest ◽  
Old Growth Forest

Abstract Background: Gap size and environmental gradient have fundamental influence on the tree species coexistence and community assembly. We studied the regeneration and coexistence of three co-dominant tree species in three different gap size (large gap, 201-402 m2; medium gap, 101-200 m2; small gap, 38.8-100 m2) along an elevation gradient (between 3000m and 3500m) in an old-growth forest, on Mount Nadu in southwest China. Results: We found that the photosynthetic photon flux density (PPFD) was positively affected by gap size during the growing season. All three species had a higher regeneration density in large gaps, but the detailed response to treatments for each species depended on its stem size. Gap size had a significant positive effect on the regeneration density of Abies faxoniana small trees and Betula utilis saplings, but had no significant effect on Acer maximowiczii regeneration density. Saplings regeneration density is more sensitive to elevation compared to small trees regeneration density. Large gaps magnified the negative effects of elevation on regeneration density. Our findings indicated that Abies may maintain its regeneration advantage with low-intensity canopy disturbance, and large gap may provide excellent opportunities for broadleaf species (Betula and Acer) establishment and regeneration in this subalpine coniferous forest. Conclusion: Microhabitats heterogeneity controlled by characteristics of forest gaps along an elevation affected regeneration niche difference of tree species, which contributed to species coexistence and community assembly processes.

scholarly journals Structure, composition and diversity of restored forest ecosystems on mine-spoils in South-Western Ghana

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252371
Author(s):  
Bertrand Festus Nero
Keyword(s):  
Stand Structure ◽  
Species Abundance ◽  
Species Abundance Distribution ◽  
Abundance Distribution ◽  
Mixed Species ◽  
Climax Species ◽  
Mine Spoils ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
And Control

In response to national policy obligations, many mining companies in Ghana have restored/reclaimed degraded mined out sites through revegetation. The area extent of such restored areas is unknown and there is also paucity of data on success of restoration, species diversity and compositional dynamics of such restored landscapes, particularly using mixed species. This study assessed stand structure, diversity and composition dynamics of sites restored with mixed species and models species abundance distribution on these sites. Three reclaimed and one control site (adjacent natural forest) were inventoried using 27, 30 x 30 m plots on the Hwini-Butre and Benso concession of the Golden Star Wassa Limited. Overall 3057 (per 24 plots) and 150 (per 3 plots) individual trees were recorded in the overstorey of the reclaimed and control sites, respectively. In all, 31 species in 13 families occurred on the reclaimed site while 61 species in 29 families occurred on the control. Species richness, abundance and diversity were significantly lower in the reclaimed sites than the control in the overstorey (p≤0.018), mid-storey (p ≤ 0.032), and understorey (p≤ 0.031). Species composition of the reclaimed and control sites were mostly dissimilar in the overstorey, midstorey, and understorey. However, the midstorey and overstorey of the reclaimed sites showed high similarity in composition (Jaccard’s index = 0.817). Pioneer and shade-tolerant species were most dominant in the understorey of the control while only shade-tolerant species (mostly herbs and grasses) dominated the reclaimed sites. Species abundance distribution of both reclaimed and control sites followed the geometric series model, indicating that both sites are disturbed but at different intensities. It is concluded that reclamation with mixed species does not necessarily lead to rapid restoration of indigenous climax species on mine spoils. Nonetheless, it may lead to accomplishments of short-term goals of stabilizing and protecting landscapes while conditioning the sites for colonisation of the climax species.

Long-term permanent plot observations of vegetation dynamics in Budongo, a Ugandan rain forest

2000 ◽  
Vol 16 (6) ◽  
pp. 865-882 ◽  
Author(s):  
DOUGLAS SHEIL ◽  
STEPHEN JENNINGS ◽  
PETER SAVILL
Keyword(s):  
Mortality Rate ◽  
Tree Species ◽  
Size Structure ◽  
Series Data ◽  
Forest Plot ◽  
Stem Size ◽  
Tolerant Species ◽  
Large Trees ◽  
Shade Tolerant Species

Species composition and turnover that have occurred in a series of permanent sample plots established during the 1930s and 1940s in Budongo, a semi-deciduous Ugandan forest, are reported. The plots were established as part of a sequence first used to describe forest succession, five of which have been maintained and which were last measured in 1992-1993. One plot (plot 7) provides 53 y of data from old-growth pristine forest. Plot 15 was established in wooded grassland at the forest edge and is now closed high forest. Evaluation of the remaining three plots is complicated by silvicultural interventions carried out in the 1950s. Forty species have been added since the first evaluations and a total of 188 tree species (over 80% of Budongo's forest tree flora, and including two exotics) has now been recorded from within the plots. The pattern of shade-tolerance in the original plot series conforms to patterns expected for succession with an increasing proportion of shade-tolerant species with development, and large stems appearing to ‘lag behind’ smaller stems in this respect. The time series data are less consistent, and while plot 7 increased in the proportion of shade-tolerant stems through time, the proportion of shade-tolerant species actually declines. Stem-turnover (the mean of mortality and recruitment) slowed with implied successional stage. Most species have a higher recruitment than mortality rate and stem numbers have thus increased in all plots. This is most pronounced in the putatively ‘early successional’ plot. Stem size structure has changed within the plots, with an increased proportion of smaller stems. Species show different rates of turnover and these vary from plot to plot and period to period. In plot 7, the overall mortality rate decreased with initial stem size. Estimates imply that some tree species may easily live longer than 500 y after reaching 10 cm DBH, and that 1000 y is possible. The importance of large trees in determining forest dynamics is illustrated by the finding that death of only seven stems in plot 7 contributed over 60% of net basal area losses recorded over the 53-y observation period. Many of the observed patterns were not predicted and could only have been found by long-term studies.

scholarly journals Traits controlling shade tolerance in tropical montane trees

2019 ◽  
Vol 40 (2) ◽  
pp. 183-197 ◽  
Author(s):  
Elisée Bahati Ntawuhiganayo ◽  
Félicien K Uwizeye ◽  
Etienne Zibera ◽  
Mirindi E Dusenge ◽  
Camille Ziegler ◽  
...  
Keyword(s):  
Tree Species ◽  
Shade Tolerance ◽  
Plant Traits ◽  
Plant Biomass ◽  
Leaf Traits ◽  
Interspecific Variation ◽  
Clear Understanding ◽  
Tolerant Species ◽  
Whole Plant ◽  
Shade Tolerant Species

Abstract Tropical canopies are complex, with multiple canopy layers and pronounced gap dynamics contributing to their high species diversity and productivity. An important reason for this complexity is the large variation in shade tolerance among different tree species. At present, we lack a clear understanding of which plant traits control this variation, e.g., regarding the relative contributions of whole-plant versus leaf traits or structural versus physiological traits. We investigated a broad range of traits in six tropical montane rainforest tree species with different degrees of shade tolerance, grown under three different radiation regimes (under the open sky or beneath sparse or dense canopies). The two distinct shade-tolerant species had higher fractional biomass in leaves and branches while shade-intolerant species invested more into stems, and these differences were greater under low radiation. Leaf respiration and photosynthetic light compensation point did not vary with species shade tolerance, regardless of radiation regime. Leaf temperatures in open plots were markedly higher in shade-tolerant species due to their low transpiration rates and large leaf sizes. Our results suggest that interspecific variation in shade tolerance of tropical montane trees is controlled by species differences in whole-plant biomass allocation strategy rather than by difference in physiological leaf traits determining leaf carbon balance at low radiation.

scholarly journals Accuracy of Regeneration Surveys in New England Northern Hardwoods

2007 ◽  
Vol 24 (3) ◽  
pp. 227-229 ◽  
Author(s):  
William B. Leak
Keyword(s):  
Species Composition ◽  
New England ◽  
New Hampshire ◽  
Northern Hardwoods ◽  
Harvest Intensity ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
Small Plot ◽  
Bartlett Experimental Forest ◽  
Current Species

Abstract Four 5-ac demonstration harvests were initiated in 1951 on the Bartlett Experimental Forest, New Hampshire: light selection, moderate selection, diameter limit, and liquidation. In 1952 and 1959, regeneration surveys were conducted that measured several different attributes of the seedlings and saplings in the cutover stands. In 2005, the stands were remeasured to determine the relationships of the various regeneration measures to current species composition of the pole-timber portion of the stands. Although predictions were somewhat variable and imperfect, the best measures for shade-tolerant species were those that took account of the sapling layer, and measures based on the dominant stem per small plot were best for less-tolerant species. Combining both attributes, these results suggest that the best approach would be a small-plot survey (milacre or slightly larger) that simply records the dominant stem per plot including stems up through the sapling size classes (less than 4.5-in. dbh). This could be taken before harvest, to predict the effects of a light partial cut, or 5–7 years after harvest, to predict future species composition after any harvest intensity.

scholarly journals Leaf optical properties as affected by shade in saplings of six tropical tree species differing in successional status

2003 ◽  
Vol 15 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Rogéria Pereira Souza ◽  
Ivany F. M. Válio
Keyword(s):  
Optical Properties ◽  
Chlorophyll Content ◽  
Tree Species ◽  
Tropical Tree ◽  
Successional Status ◽  
Tropical Tree Species ◽  
Leaf Chlorophyll ◽  
Tolerant Species ◽  
Leaf Optical Properties ◽  
Shade Tolerant Species

Tree species differing in successional status may present different responses to shade. Adjustments at leaf level may affect their optical properties, leading to changes in PAR (photosynthetically active radiation) absorbance. The aim of this study was to evaluate leaf optical properties as affected by understory shade in saplings of six tropical tree species differing in successional status and degree of shade tolerance. Chlorophyll content and specific leaf area (SLA) were also evaluated. The effects of shade on leaf optical properties and chlorophyll content differed among the studied species, whereas increased SLA was a common response for all species, reflecting the occurrence of thinner leaves under shade. The three studied shade-tolerant species - Esenbeckia leiocarpa, Myroxylon peruiferum and Hymenaea courbaril - presented a greater PAR absorbance under shade. The response of the shade-intolerant species was varied. While Schizolobium parahyba also showed a greater PAR absorbance under shade, Chorisia speciosa did not alter its spectral properties and Cecropia pachystachya presented an opposite pattern, with smaller absorbance under shade. Increases in leaf chlorophyll content were significant in the shade-tolerant species, whereas they were absent or of small magnitude in the shade-intolerant ones. Although the shade-induced decrease of leaf reflectance was the only response that safely discriminated tolerant from intolerant species, the adjustments in leaf chlorophyll content and optical properties were more consistent for the tolerant species.

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