Bryophyte relationships with environmental and structural variables in Tasmanian old-growth mixed eucalypt forest

2006 ◽  
Vol 54 (3) ◽  
pp. 239 ◽  
Author(s):  
P. A. M. Turner ◽  
J. B. Kirkpatrick ◽  
E. J. Pharo
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Canopy Cover ◽  
Basal Area ◽  
Mean Annual Temperature ◽  
Old Growth ◽  
Moss Species ◽  
Eucalypt Forest ◽  
Structural Variables ◽  
Negative Predictor

The species richness and species composition of bryophytes (mosses and liverworts) was recorded at 33 sites in Tasmanian old growth mixed eucalypt forest. A total of 202 bryophyte taxa were recorded, consisting of 115 liverworts and 87 mosses. This constitutes approximately one third of the total bryophyte flora for Tasmania. Mean liverwort species richness per site was higher than moss species richness. Latitude was found to be a positive predictor in all multiple regression models of bryophyte, moss and liverwort species richness. Mean annual temperature and rainfall of the driest month were positive predictors for bryophyte and liverwort species richness. Basal area of the treefern Dicksonia antarctica Labill. was a negative predictor of liverwort species richness. Latitude, variables relating to moisture, mean annual temperature, rainfall of the driest month and basal area of Dicksonia antarctica were the most significant components in predicting variation in bryophyte, moss and liverwort species composition. There were few relationships between the variables of canopy cover and soil nutrients and bryophyte species richness and composition. Substrate variables were found to be important components in predicting variation in moss and bryophyte species composition.

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.

Effects of biomass extraction on vegetation structure, diversity and composition of forests in Sariska Tiger Reserve, India

2005 ◽  
Vol 32 (3) ◽  
pp. 248-259 ◽  
Author(s):  
RAMAN KUMAR ◽  
GHAZALA SHAHABUDDIN
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Vegetation Structure ◽  
Riparian Forest ◽  
Canopy Cover ◽  
Basal Area ◽  
Vegetation Types ◽  
Tiger Reserve ◽  
Scrub Forest ◽  
Structure Diversity

Despite the fact that tropical dry forests are being exploited on a large scale for various forest products, there has been limited evaluation of the accompanying ecological impacts. In particular, there is no information on the effects of widespread biomass extraction such as grazing and firewood collection. A study was carried out in Sariska Tiger Reserve in northern India, to investigate the effects of biomass extraction on forest vegetation composition, diversity and structure. Biomass extraction caused significant changes in forest vegetation structure and species composition in the tree layer but the extent of these changes varied across the three major vegetation types found in the Reserve. Anogeissus-dominated slope forest showed significantly lower mean canopy cover, tree density, tree basal area and height of trees in disturbed sites in comparison to undisturbed sites. Riparian forest showed lower mean canopy cover, tree basal areas and number of recorded tree species in disturbed sites. Scrub forest had lower mean canopy cover, tree basal area and tree height. There were fewer tall trees but greater number of short trees in disturbed sites of all three vegetation types. Girths of trees similarly shifted towards lower values in riparian and scrub forest. In Anogeissus-dominated forest, disturbed and undisturbed sites did not differ in proportions of trees in various girth-classes. Tree species richness was substantially lower in disturbed sites of Anogeissus-dominated and riparian forest in comparison to undisturbed sites, but was not affected by disturbance in scrub forest. Understorey species richness was higher in disturbed sites of all three vegetation types but understorey changed structurally only in Anogeissus-dominated forest. Overall tree and understorey species composition was significantly different between disturbed and undisturbed sites of Anogeissus-dominated forest, but was unchanged in scrub and riparian forest. Observed changes in vegetation structure, diversity and composition of the different vegetation types due to biomass extraction have implications for biodiversity conservation in tropical dry forest ecosystems, and need to be addressed in future forest management planning.

Forest Regrowth on the Cumberland Plateau and Implications for Productive Management

1983 ◽  
Vol 7 (4) ◽  
pp. 208-212 ◽  
Author(s):  
Robert N. Muller
Keyword(s):  
Species Composition ◽  
Basal Area ◽  
Stand Density ◽  
Cumberland Plateau ◽  
Old Growth ◽  
Nutrient Pools ◽  
Old Growth Forest ◽  
Composition And Structure ◽  
Second Growth ◽  
Commercial Species

Abstract An old-growth forest and a 35-year-old, second-growth forest on the Cumberland Plateau were studied to compare species composition and structure. Species composition and total basal area of the two stands did not differ, although total stand density was 19 percent lower and basal area of commercial species was 25 percent higher in the old-growth than in the second-growth stand. Analysis of size-class distributions showed that both stands were best represented by an inverse J-shaped distribution, which best describes old-age stands. The rapid regeneration of the second-growth stand seems to be the result of minimal disturbance to accumulated nutrient pools in the soil. The importance of these accumulated nutrient pools and implications for forest management on the Cumberland Plateau are discussed.

scholarly journals Identifying Variables to Discriminate between Conserved and Degraded Forest and to Quantify the Differences in Biomass

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1020
Author(s):  
Yan Gao ◽  
Margaret Skutsch ◽  
Diana Laura Jiménez Rodríguez ◽  
Jonathan V. Solórzano
Keyword(s):  
Aboveground Biomass ◽  
Tropical Dry Forest ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Dry Forest ◽  
Rank Test ◽  
Degraded Forest ◽  
Forest Survey ◽  
Structural Variables

The purpose of this work was to determine which structural variables present statistically significant differences between degraded and conserved tropical dry forest through a statistical study of forest survey data. The forest survey was carried out in a tropical dry forest in the watershed of the River Ayuquila, Jalisco state, Mexico between May and June of 2019, when data were collected in 36 plots of 500 m2. The sample was designed to include tropical dry forests in two conditions: degraded and conserved. In each plot, data collected included diameter at breast height, tree height, number of trees, number of branches, canopy cover, basal area, and aboveground biomass. Using the Wilcoxon signed-rank test, we show that there are significant differences in canopy cover, tree height, basal area, and aboveground biomass between degraded and conserved tropical dry forest. Among these structural variables, canopy cover and mean height separate conserved and degraded forests with the highest accuracy (both at 80.7%). We also tested which variables best correlate with aboveground biomass, with a view to determining how carbon loss in degraded forest can be quantified at a larger scale using remote sensing. We found that canopy cover, tree height, and density of trees all show good correlation with biomass and these variables could be used to estimate changes in biomass stocks in degraded forests. The results of our analysis will help to increase the accuracy in estimating aboveground biomass, contribute to the ongoing work on REDD+, and help to reduce the great uncertainty in estimation of emissions from forest degradation.

The effects of partial cutting on forest plant communities of western hemlock – Sitka spruce stands in southeast Alaska

2001 ◽  
Vol 31 (12) ◽  
pp. 2067-2079 ◽  
Author(s):  
Robert L Deal
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Plant Species Richness ◽  
Plant Community Structure ◽  
Old Growth ◽  
Partial Cutting ◽  
Southeast Alaska ◽  
Clear Cutting

The effects of partial cutting on plant species richness, community structure, and several understory species that are important for deer forage were evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12–96 years ago when 16–96% of the former stand basal area was removed. The species richness and community structure of understory plants were similar in uncut and partially cut plots. However, plots where more than 50% of the basal area was cut had a significantly different plant community structure. Species composition and abundance also appeared to be distinctly different between hemlock-dominated and spruce-dominated stands. Partial cutting did not significantly change abundance for most of the important forage species for deer. The similarity in plant community structure between partially cut and uncut old-growth stands may be related to forest stand structures. The heterogeneous stand structures that develop after partial cutting are more similar to old-growth stands than to the uniform young-growth stands that develop after stand replacing disturbances such as clear-cutting.

scholarly journals Biodiversity recovery of Neotropical secondary forests

2019 ◽  
Vol 5 (3) ◽  
pp. eaau3114 ◽  
Author(s):  
Danaë M. A. Rozendaal ◽  
Frans Bongers ◽  
T. Mitchell Aide ◽  
Esteban Alvarez-Dávila ◽  
Nataly Ascarrunz ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Tree Species ◽  
Anthropogenic Disturbance ◽  
Secondary Forests ◽  
Old Growth ◽  
Rarefaction Analysis ◽  
Old Growth Forest ◽  
Dual Strategy ◽  
Tropical Landscapes

Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes.

scholarly journals Diversity and composition of moss guilds on uprooted trees in Central European mountain forests: effects of uprooting components and environmental variables

2021 ◽  
Vol 78 (2) ◽  
Author(s):  
Monika Staniaszek-Kik ◽  
Jan Żarnowiec ◽  
Ewa Stefańska-Krzaczek
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Type ◽  
Species Traits ◽  
Common Species ◽  
Forest Community ◽  
Moss Species ◽  
Component Type ◽  
Species Cover ◽  
Tree Uprooting

Abstract Key message The size of the structural components of the root–pit–mound complex was crucial for high moss species richness. Root plates, pits, and mounds were similar in terms of moss species composition, which was mostly determined by forest type. Context Uprooted trees may be colonized by different terricolous mosses including common species and specialists. Aims The main aim of the present study was to analyze the relative effects of tree uprooting on mosses. Methods We used the parametric ZIGLMM and GLMM models to explain the richness and abundance of the moss species and double constrained correspondence analysis (dc-CA) to analyze species composition. Results The size of components of RPM complexes had a positive effect on moss species richness. The species cover of mosses was positively correlated with elevation. Species richness was partly dependent on forest type and species cover on component type and age of the RPM complex. The most important factor diversifying species composition was the type of forest. Species traits were also related to forest communities. Conclusion Uprooted trees are worth keeping in forest community, especially large ones. Moreover, the conservation value of uprooted trees in woodlands is higher if they are dispersed in different forest types.

scholarly journals The long-term dynamics of the old-growth structure in the National Nature Reserve Badínsky prales

2020 ◽  
Vol 66 (No. 12) ◽  
pp. 501-510
Author(s):  
Ladislav Šumichrast ◽  
Jaroslav Vencurik ◽  
Ján Pittner ◽  
Stanislav Kucbel
Keyword(s):  
Species Composition ◽  
Relative Density ◽  
Detrended Correspondence Analysis ◽  
Basal Area ◽  
Importance Value ◽  
Old Growth ◽  
Stand Volume ◽  
Structure Dynamics ◽  
Old Growth Forest

The main goal of this paper was to evaluate structure dynamics in the fir-beech, old-growth forest Badínsky prales. Measurements were taken on four permanent research plots (0.5 ha each) between 1970 and 2018, typically in ten-year intervals. In order to assess long-term structure dynamics, this study used basic stand characteristics and selected structural indices – the relative density (RD), coefficient of homogeneity (H), and structural complexity index (SCI). Species composition was quantified by the relative importance value (RIV), and a detrended correspondence analysis was carried out for the visualisation of long-term changes. The long-term mean of the stand volume reached 634 ± 99 m3·ha−1, and the mean of the basal area was 36.6 ± 4.0 m2·ha–1. Calculated values of the coefficient of homogeneity (1.46–2.54) were similar to values in other old-growth forests with a comparable tree species composition. An increasing trend in beech RIV values was observed; on the other hand, fir RIV values fell by approximately 20%–25%. In 2018, maximal values of the basal area, stand volume and relative density were recorded. These high values may indicate better growth conditions due to climate change, as well as fewer disturbance events in the last few decades.

scholarly journals Effects of Forest Regeneration on Crickets: Evaluating Environmental Drivers in a 300-Year Chronosequence

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Neucir Szinwelski ◽  
Cassiano S. Rosa ◽  
José H. Schoereder ◽  
Carina M. Mews ◽  
Carlos F. Sperber
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Regeneration ◽  
Canopy Cover ◽  
Environmental Drivers ◽  
Patch Area ◽  
Forest Patch ◽  
Regeneration Time ◽  
Explanatory Variables ◽  
Litter Depth

We evaluated the relation of cricket species richness and composition with forest regeneration time, evaluating canopy and litter depth as environmental drivers. Effects of forest patch area, nearest distance to the 300-year patch, cricket abundance, sampling sufficiency, and nestedness were also evaluated. We collected 1174 individuals (five families, 19 species). Species richness increased asymptotically with regeneration time and linearly with canopy cover and litter depth. Canopy cover increased linearly, while litter depth increased asymptotically. Richness was not affected by patch area and nearest distance to the 300-year patch. Richness increased with cricket abundance, and this explanation could not be distinguished from regeneration time, evidencing collinearity of these two explanatory variables. Rarefaction curve slopes increased with regeneration time. Species composition differed among patches, with no nested pattern. We suggest that regeneration and consequent increases in canopy and litter promote recovery of cricket biodiversity, abundance, and changes in species composition. We conclude that the recovery of cricket diversity involves an increase along the spatial scale of complementarity, together with a change in species composition.

Riparian bryophyte vegetation in the Cascade mountain range, Northwest U.S.A.: patterns at different spatial scales

1997 ◽  
Vol 75 (5) ◽  
pp. 744-761 ◽  
Author(s):  
Bengt Gunnar Jonsson
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Environmental Gradients ◽  
Woody Debris ◽  
Spatial Scales ◽  
Regional Distribution ◽  
Mountain Range ◽  
Old Growth ◽  
Old Growth Forest ◽  
Stream Size

Riparian forests are productive and species rich ecosystems where the vegetation is structured by sharp environmental gradients. The study describes community patterns of bryophytes in stream-side forests, relates these patterns to major environmental gradients, and compares within-site factors with site level variables. Samples were collected from 360 plots 2 × 4 m in size distributed among 42 sites in old-growth Pseudotsuga–Tsuga forests. The sites ranged from 420 to 1250 m asl and stream size from 1st to 5th order streams. There were significant changes in species richness and composition along several environmental gradients. Richness within sites varied among different geomorphic surfaces with the highest number of species on areas periodically flooded. Richness was also higher in plots with high abundance of woody debris. No site level factors influenced richness at the sample plot level, while the highest species number at the site level was for large streams. The main gradients in the species composition within sites were changes with increasing distance from the stream and amount of woody debris. Both elevation and stream size significantly influenced species composition. The complex set of factors that influenced species richness and composition implies that management of riparian vegetation must be based on both coarse scale considerations such as regional distribution of different stream types and fine scale factors such as spatial availability of different substrate types. Key words: old-growth forest; CCA analysis; fluvial disturbance; bryophytes; elevation effects; coarse woody debris.

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