Effects of forest plantation management on herbaceous-layer composition and diversity

2002 ◽  
Vol 80 (4) ◽  
pp. 378-389 ◽  
Author(s):  
Mark R Roberts
Keyword(s):  
Species Composition ◽  
Diversity Indices ◽  
Forest Harvesting ◽  
Herbaceous Layer ◽  
Age Classes ◽  
Forest Habitat ◽  
Total Species Richness ◽  
Plantation Age ◽  
Intensively Managed ◽  
Natural Stands

I compared the species composition and diversity of vascular plants in the herbaceous layer from a chronosequence of intensively managed spruce (Picea) plantations in three age-classes (5–7, 10–12, 14–16 years) with natural, mature stands (ca. 90 years) in southeastern New Brunswick, Canada. Total species richness (stand level) averaged 81–84 species in the three plantation age-classes compared with 64 species in the natural stands; richness of forest habitat species alone was 33–36 in the plantations and 37 in the natural stands. More fertile sites had significantly higher values for Hill's diversity indices (N0, N1, N2). Mean N0, N1, and N2 (subplot level) did not differ among stand types for all species, but N1 and N2 were significantly greater in the natural stands than in one or two plantation age-classes for forest habitat species alone. The two younger age-classes of plantations differed significantly in composition from the natural stands and the plantations became slightly more similar (Sørensen's index) to the natural stands with increasing age. One forest habitat species was lost and 24 others decreased in cover in the plantations. Tracking of plantations over a longer time period will be needed to determine whether these forest habitat species eventually regain their former abundance.Key words: chronosequence, forest harvesting, herbaceous layer, plantations, species diversity, species composition.

scholarly journals Evaluation of the corridor method for oak (Quercus sp.) cultivation using research objects in the Mircze and Kościan Forest Districts as an example

2018 ◽  
Vol 79 (1) ◽  
pp. 29-35
Author(s):  
Rafał Paluch ◽  
Wojciech Gil
Keyword(s):  
Species Composition ◽  
Quality Index ◽  
Oak Regeneration ◽  
Age Classes ◽  
Good Production ◽  
Corridor Method ◽  
Research Objects ◽  
Predicted Values ◽  
19Th And 20Th Century ◽  
Very High

Abstract The corridor method of oak (Quercus sp) cultivation is an old, forgotten silvicultural method. It was developed around the turn of the 19th and 20th century on the south-eastern borders of Poland (Podole, Wołyń) and Russia and made use of other species such as hornbeam, linden and birch as a cover for oak, which is a tree species sensitive to frosts. The nowadays recurring phenomenon of oak disease initiated a search for silvicultural alternatives and thus the usefulness of reviving the corridor method for oak regeneration was investigated by examining existing tree stands established in this way. Our research plots were located in five young stands and two in mature as well as old stands. In the stands of the 2nd and 3rd age classes, the density of oaks was observed to be 1500–3500/ha, which accounted for 30–50%. The density of oak in old stands (7th age class) was similar to model-predicted values. Furthermore, the corridor method gave very good production results as exemplified by the oak stands growing on the fresh broadleaved site, which had a very high stand quality index. In addition, the species composition was observed to diversify throughout these oak stands’ development, thus supporting arguments for the conservation and preservation of oak-hornbeam forests. To summarise, the prerequisites for the success of the corridor method are systematic cuts of young stands (forest cultures and thickets) to inhibit the growth of accompanying undesired species and limiting the number of grazing animals.

scholarly journals Floristic composition and phytodiversity status of Sitakunda Ecopark, Chittagong, Bangladesh

2016 ◽  
Vol 5 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Md Anwarul Islam ◽  
Mohammad Mahfuzur Rahman ◽  
Gazi Mosharof Hossain
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Monsoon Season ◽  
Vascular Plant ◽  
Floristic Composition ◽  
Diversity Indices ◽  
Vascular Plant Species ◽  
Plant Groups ◽  
Plant Families

The present study dealt with the exploration and documentation of the floristic composition and phyto-diversity of Sitakunda Eco-park, Chittagong, Bangladesh. A total of 412 vascular plant species under 315 genera belonging to 94 plant families have been recorded from the study area during February, 2013 to April, 2015. Out of these recorded taxa, 330 were dicotyledons, 62 were monocotyledons, 5 were gymnosperms and 15 were pteridophytes. Among those, the maximum 144 species belonged to herbs followed by 138, 75 and 55 species as trees, shrubs and climbers, respectively. The species composition among the plant families varied in plant groups. In dicotyledonous group, Euphorbiaceae appeared to be the largest family with 35 species, whereas Poaceae showed the largest family containing 30 species among monocotyledonous group. The highest values of both Shannon-Weiner and Simpson diversity indices have been observed as 3.82 and 0.98, respectively to site D during monsoon season, whereas the lowest values 3.19 and 0.95, respectively of these indices were recorded in site A during summer season.Jahangirnagar University J. Biol. Sci. 5(1): 29-45, 2016 (June)

Powerline easements through forests: a case study of impacts on avifauna

1998 ◽  
Vol 4 (1) ◽  
pp. 79 ◽  
Author(s):  
Jack Baker ◽  
Ross L. Goldingay ◽  
Robert J. Whelan
Keyword(s):  
Species Richness ◽  
Bird Community ◽  
Forest Habitat ◽  
Bird Abundance ◽  
Point Counts ◽  
Southeastern Australia ◽  
Total Species Richness ◽  
New Type ◽  
Forest Values

Powerline easements are typically a strip cleared of trees and tall vegetation to a width of approximately 50 m. They may affect avifauna by modification and fragmentation of forest habitat. We investigated the responses of the bird community to easements at three sites in southeastern Australia using 25 m radius point-counts spaced at 50 m intervals from the easement to 300 m inside the forest. The easements caused an absolute loss of habitat for forest avifauna, with abundance and species richness at the easement less than 20% of the forest values. Four species of easement opportunist and one easement specialist provided evidence that the easement represented a new type of habitat for avifauna. A barrier effect of fragmentation may occur for four species of easement avoiders. These were small to medium-sized terrestrial birds associated with dense ground and/or understorey cover. The edge effect of fragmentation was an adverse impact on forest avifauna. At the margin (25?125 m from the easement) of the forest, bird abundance, mean species richness and total species richness were significantly less than the corresponding values for the interior (225?325 m) of the forest. The mean abundance at the sites varied from 13.0?17.7 birds/ha and the species richness varied significantly among sites. The adverse impacts of powerline easements on native avifauna could be minimized by site-specific management which includes strategies to minimize the loss of forest habitat and to ameliorate the effects of fragmentation.

Conservation value of koa (Acacia koa) reforestation areas on Hawaii Island

2018 ◽  
Vol 24 (1) ◽  
pp. 35
Author(s):  
Laurie Strommer ◽  
Sheila Conant
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Native Species ◽  
Canopy Cover ◽  
Basal Area ◽  
Forest Tree ◽  
Native Forest ◽  
Acacia Koa ◽  
Total Species Richness ◽  
Hawaii Island

Efforts to restore forests for ecological and economic benefit in Hawaii are converging on koa (Acacia koa), an endemic dominant or codominant canopy tree common across broad elevation and moisture gradients. We quantified plant species composition and forest structure in koa reforestation areas (KRAs) and in nearby intact native forest on Hawaii Island. Total species richness and percentage native species richness were lower in the plantation forests than in the intact forests, although species richness in the KRAs at one site was not significantly different from that in intact forest. Tree, sapling, and seedling densities differed between KRAs and forest sites at one site. At another, the native forest and one KRA had similar tree and seedling densities and similar canopy height and percentage canopy cover. Total stand basal area was greatest in the intact forest at both sites, although the basal area for the KRAs at one site exceeded those for intact forest at the other. Koa plantings can be structurally similar to intact forests though species composition differs. Our results suggest that koa forestry can facilitate native understorey development in some cases.

Pine Growth-Rate Changes in the Southeast: A Summary of Key Issues for Forest Managers

1988 ◽  
Vol 12 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Alan A. Lucier
Keyword(s):  
Atmospheric Pollutants ◽  
Managed Forest ◽  
Land Use Patterns ◽  
Usda Forest Service ◽  
Use Patterns ◽  
The Past ◽  
Key Issues ◽  
Intensively Managed ◽  
Natural Stands ◽  
Stand Conditions

Abstract Forest inventory data collected by the USDA Forest Service shows that pine forests in the Southeast have changed in many ways since the 1950s. The average age and density of natural stands has increased substantially over the past 30 years, perhaps reflecting the maturation of a large number of stands established between 1945 and 1965. Growth rates of some classes of trees and stands have decreased, but it is not known whether increases in age and density are largely responsible. The existence of growth reductions in natural stands is an expected consequence of the documented changes in stand conditions. The magnitude of the growth reductions, however, cannot be objectively defined as normal or abnormal on the basis of existing data. Researchers are attempting to define the contributions of stand conditions, drought, land-use patterns, atmospheric pollutants, and other factors to observed growth reductions. There is at present no demonstrated link between air pollutants and growth reductions in natural pine stands and no evidence of growth reductions on intensively managed forest industry lands. South. J. Appl. For. 12(2):84-89.

The effects of silvicultural disturbances on cryptogam diversity in the boreal-mixedwood forest

2002 ◽  
Vol 32 (1) ◽  
pp. 38-51 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell
Keyword(s):  
Species Richness ◽  
Species Abundance ◽  
Diversity Indices ◽  
Forest Harvesting ◽  
Aerial Application ◽  
Forest Diversity ◽  
Four Blocks ◽  
Abundance And Diversity ◽  
Species Richness And Abundance ◽  
And Function

In northern forests, cryptogams (spore producing plants) occupy a key position in forest ecosystem diversity and function. Forest harvesting and silvicultural practices have the potential to reduce cryptogam diversity. This project uses four blocks that were mechanically site prepared, planted with a single conifer species, and subsequently subjected to five conifer release treatments: (1) motor-manual cleaning, (2) mechanical brush cutting, (3) aerial application of triclopyr, (4) aerial application of glyphosate, and (5) control (untreated clearcut). Five 10 × 10 m subplots were installed in each of the five treatment plots and the uncut forest on the four blocks. Botanical surveys were conducted before and 1–5 years after treatments. Species richness and abundance, Shannon's and Heip's indices, and rank abundance diagrams clearly show that richness and abundance were affected by silvicultural treatments. Vegetation management treatments resulted in significant reductions in cryptogam diversity, to the point that only a few colonists and drought-tolerant species remained. Cryptogam diversity was ranked in the following order: forest > clearcut > mechanical clearing > herbicide treatment. Herbicide treatments had the greatest initial effect on species richness, species abundance, and diversity indices. Cryptogam diversity showed signs of recovery 5 years after treatments. Missed strips (untreated areas) within a clearcut provided a refuge for remnant communities of forest cryptogams that could play a key role in the rehabilitation forest diversity.

Spatial patterns of meiofauna and diversity of nematode species assemblages in the Uvea lagoon (Loyalty Islands, South Pacific)

2008 ◽  
Vol 88 (5) ◽  
pp. 931-940 ◽  
Author(s):  
Y. Guo ◽  
M.-N. Helleouet ◽  
G. Boucher
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Environmental Parameters ◽  
Nematode Species ◽  
Abundant Species ◽  
Diversity Indices ◽  
Species Assemblages ◽  
Leeward Side ◽  
Local Composition ◽  
Total Species Richness

Meiofauna assemblages were investigated at 15 stations on triplicated samples in the Uvea Atoll (Loyalty Islands) in relation to 9 selected environmental parameters. Spatial patterns and variability of meiofauna density were quantified according to location, macrofauna and nematode species assemblages. Meiofauna was dominated by ciliates and nematodes. Densities of total meiofauna and of most of the meiofauna taxa were significantly higher in the back reef North Pléiades stations than the leeward side of the Island. The highest correlation between biotic patterns and environmental parameters that best explains the pattern was with sediment thickness and to a lesser extent organic matter, C/N ratio and depth. One hundred and thirty-four nematode species were identified with four dominant species Chromadora macrolaimoides, an undescribed species of Bolbonema, Daptonema svalbardense and Prochromadorella septempapillata. Three significantly different nematode species assemblages were detected in two of the previously described macrofauna assemblages by cluster analysis and multidimensional scaling methods suggesting that nematodes are more sensible ecological indicators than macrofauna. Diversity indices based on dominance were not significantly different among the three nematode species assemblages but indices based on species richness and rarefaction were significantly higher leeward of Uvea Island. Estimates of total species richness showed no sign of stabilizing with sample size. However, rare species stabilized very quickly, whereas abundant species were added with increasing sampling coverage, indicating a high spatial variability of the local composition of nematodes.

Forest harvesting impacts on soil properties and vegetation communities in the Northwest Territories

2002 ◽  
Vol 32 (4) ◽  
pp. 713-724 ◽  
Author(s):  
Michael D Bock ◽  
Ken CJ Van Rees
Keyword(s):  
Species Composition ◽  
Soil Properties ◽  
Forest Harvesting ◽  
Understory Vegetation ◽  
Vegetation Community ◽  
Clear Cut ◽  
Mixedwood Forests ◽  
Crown Cover ◽  
Composition And Structure ◽  
Harvesting Systems

Management of boreal mixedwood forests in Canada has traditionally relied almost exclusively on the clear-cut silvicultural system. In recent years, greater utilization of the hardwood component of boreal mixedwoods and increased societal concerns over maintenance of the integrity and sustainability of these ecosystems has provided impetus for forest managers to consider alternative silvicultural practices in boreal mixedwood forests. Little is currently known, however, concerning the response of soils and vegetation to forest harvesting systems in the mixedwood forests of the Liard River valley, Northwest Territories (NWT). Therefore, the objective of this study was to quantify the effects of patch clear-cut, strip clear-cut, and clear-cut harvesting systems on soil properties and understory vegetation composition and structure. Treatment sites with 3 or 4 years of recovery since harvesting and adjacent uncut forest sites were sampled using transect methodology. Soil samples were collected and understory vegetation community species composition and percent crown cover were assessed in 1-m2 quadrats. Compared with the range of conditions present in the uncut forest, increases in mineral soil bulk density (2%), exchangeable calcium (7%), LFH horizon thickness (13%), pH (0.2 units), and total organic carbon (5%) and decreases in LFH horizon total nitrogen (6%) and exchangeable potassium (22%) were observed following harvesting. Harvesting resulted in the reduction in crown cover of feathermoss species and increased abundance of shrub and herb species and minimal changes to species composition. Multivariate analysis of the data indicated that the method of harvesting did not result in significant differences in species composition and structure of the understory vegetation community. Overall, winter harvesting of these boreal mixedwood sites did not have a major impact on the majority of soil properties evaluated or on the species composition of the understory vegetation community.

scholarly journals Variations in Total Species Richness and the Unevenness of Species Abundance Distribution between Two Distant Conus Communities (Neogastropoda): A Case Study in Mannar Gulf (India)

2019 ◽  
pp. 1-18
Author(s):  
Jean Béguinot
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Species Abundance ◽  
Species Abundance Distribution ◽  
Abundance Distribution ◽  
Marine Gastropods ◽  
Total Species Richness ◽  
Species Recruitment ◽  
Total Species

The genus Conus forms a conspicuous and rather homogeneous group within marine Gastropods. This makes it all the more interesting to focus on the sub-communities formed by Conus species and to analyze the potential specificities in the internal organization of species in these communities, in particular species richness, species abundance distribution and the effect of geographical distance between communities on differences in their respective species composition. Accordingly, two Conus communities along the coast in Mannar Gulf (India), separated by 80 km, are considered. Reliable analysis requires, first, to treat exhaustive data from complete samplings or, else – as here – to implement an appropriate extrapolation procedure to complete numerically the partial samplings. After numerical completion, substantial differences were highlighted between the two communities, not only in terms of true (total) species richness but, even more, as regards the profile and the average unevenness of the distributions of species abundance. Also, significant dissimilarity in species composition was found between the two communities, that may be tentatively attributed to either deterministic distance decay in similarity of species composition or, alternatively, to the persistence in the stochastic process of species recruitment from the regional stock of Conus planktonic larvae. This preliminary study yet requests to be complemented by other similar case studies, before drawing any safer interpretative conclusions.

Sign in / Sign up

Export Citation Format

Share Document