Elevational gradients of bryophyte diversity, life forms, and community assemblage in the southern Appalachian Mountains

2010 ◽  
Vol 40 (11) ◽  
pp. 2164-2174 ◽  
Author(s):  
Sarah E. Stehn ◽  
Christopher R. Webster ◽  
Janice M. Glime ◽  
Michael A. Jenkins
Keyword(s):  
Community Composition ◽  
Elevation Gradient ◽  
Light Availability ◽  
Basal Area ◽  
Life Forms ◽  
High Elevation ◽  
Canopy Openness ◽  
Fine Scale ◽  
Elevational Gradients ◽  
Community Assemblage

We investigated the influence of fine-scale elevational gradients and overstory disturbance on bryophyte distribution, diversity, and community composition. Bryophyte species cover and richness were sampled across 60 randomly selected plots within high-elevation spruce–fir ( Picea – Abies ) forests of Great Smoky Mountains National Park. Ordination and regression analyses revealed a fine-scale elevation gradient (700 m) in bryophyte community composition. Observed changes in bryophyte diversity and community composition were also associated with variation in deciduous basal area and thus litter composition, the prevalence of herbaceous plants, and the degree of canopy openness resulting from balsam woolly adelgid ( Adelges piceae Ratz.) infestation. Although overstory disturbances, such as those caused by the adelgid, create suitable substrate for bryophyte colonization, the corresponding increase in light availability and deciduous basal area may alter bryophyte diversity and community assemblages.

scholarly journals Quantifying Understory Complexity in Unmanaged Forests Using TLS and Identifying Some of Its Major Drivers

2021 ◽  
Vol 13 (8) ◽  
pp. 1513
Author(s):  
Dominik Seidel ◽  
Peter Annighöfer ◽  
Christian Ammer ◽  
Martin Ehbrecht ◽  
Katharina Willim ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Structural Equation Models ◽  
Light Availability ◽  
Structural Complexity ◽  
Basal Area ◽  
Ecosystem Functions ◽  
Canopy Openness ◽  
Seasonal Precipitation ◽  
Wide Range ◽  
Precipitation And Temperature

The structural complexity of the understory layer of forests or shrub layer vegetation in open shrublands affects many ecosystem functions and services provided by these ecosystems. We investigated how the basal area of the overstory layer, annual and seasonal precipitation, annual mean temperature, as well as light availability affect the structural complexity of the understory layer along a gradient from closed forests to open shrubland with only scattered trees. Using terrestrial laser scanning data and the understory complexity index (UCI), we measured the structural complexity of sites across a wide range of precipitation and temperature, also covering a gradient in light availability and basal area. We found significant relationships between the UCI and tree basal area as well as canopy openness. Structural equation models (SEMs) confirmed significant direct effects of seasonal precipitation on the UCI without mediation through basal area or canopy openness. However, annual precipitation and temperature effects on the UCI are mediated through canopy openness and basal area, respectively. Understory complexity is, despite clear dependencies on the available light and overall stand density, significantly and directly driven by climatic parameters, particularly the amount of precipitation during the driest month.

scholarly journals Bird assemblages in natural and urbanized habitats along elevational gradient in Nainital district (western Himalaya) of Uttarakhand state, India

2011 ◽  
Vol 57 (3) ◽  
pp. 318-329 ◽  
Author(s):  
Dinesh Bhatt ◽  
Kamal Kant Joshi
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Community Composition ◽  
Bird Species ◽  
High Elevation ◽  
Urban Habitat ◽  
Western Himalayas ◽  
Avian Community ◽  
Elevational Gradients ◽  
Bird Assemblages

Abstract The Indian subcontinent is amongst the biologically better known parts of the tropics and its bird fauna has been well documented. However, avian community composition and diversity along elevational gradients and amongst habitat types remains unclear in India. We attempted to estimate bird assemblages in terms of diversity, species composition, status and abundance in urban and forest habitats of Nainital district of Uttarakhand (350–2450 m asl; 29°N), Western Himalayas. We sampled different elevational gradients and to understand the effect of urbanization and season on avian community composition. Field studies were conducted during January 2005 to January 2007. Results indicated that the forest had more complex bird community structure in terms of higher species richness (14.35 vs 8.69), higher species diversity (Shannon’s index 4.00 vs 3.54), higher evenness (0.838 vs 0.811) and more rare species (17 vs 5) as compared to urban habitat. However, the abundance of 11 species was higher in urban habitats. Bird Species Richness (BSR) varied considerably among study areas (91 to 113 species), was highest (113 species) at mid elevation (1450–1700 m asl) and decreased (22 species) at high elevation (1900–2450 m asl). It seems that high BSR at mid altitudes is not caused by the presence of a group of mid altitude specialists but rather that there is an overlap in the distribution of low land and high elevation specialists at this altitude. BSR and Bird Species Diversity fluctuated across seasons but not habitat type.

Tallow tree allocates contrasting secondary chemicals in response to varying environments along elevational gradients

2020 ◽  
Vol 13 (3) ◽  
pp. 295-303
Author(s):  
Li Xiao ◽  
Jialiang Zhang ◽  
Wei Huang ◽  
Juli Carrillo ◽  
Evan Siemann ◽  
...  
Keyword(s):  
Elevation Gradient ◽  
Elevational Gradient ◽  
High Elevation ◽  
Feeding Guilds ◽  
Ecological Strategies ◽  
Elevational Gradients ◽  
Chinese Tallow ◽  
Tallow Tree ◽  
Secondary Chemicals ◽  
Varying Environments

Abstract Aims Understanding how tree species regulate multiple types of secondary chemicals along elevational gradients is critical for elucidating the physiological and ecological strategies of plants in response to varying biotic and/or abiotic environments. This study aims to examine how Chinese tallow tree (Triadica sebifera) allocates resources to the production of different secondary chemicals in response to varying environments across elevational gradients. Methods We conducted field surveys of different herbivore feeding guilds and their damage rates on Chinese tallow trees along an elevational gradient in China and measured secondary chemicals (tannins and flavonoids) in damaged and undamaged leaves. Important Findings The odds of a leaf being damaged (chewing or scarring) decreased with elevation. Flavonoid concentrations increased with elevation in undamaged leaves but decreased with elevation in damaged leaves, with quercitrin contributing most strongly to this pattern, likely as results of plant responding to changing biotic or abiotic stresses along elevational gradients. Tannin concentrations did not vary with elevation, so undamaged leaves had relatively lower tannin to flavonoid ratios at high elevation than at low elevation. Our study reveals variation in herbivory and contrasting trends in plant secondary metabolism along an elevation gradient and highlights the importance of simultaneously considering multiple types of secondary chemicals in plant physiological and ecological strategies.

scholarly journals Tree Diversity and Community Composition of the Tutong White Sands, Brunei Darussalam: A Rare Tropical Heath Forest Ecosystem

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hazimah Din ◽  
Faizah Metali ◽  
Rahayu Sukmaria Sukri
Keyword(s):  
Community Composition ◽  
Forest Ecosystem ◽  
Tree Species ◽  
Basal Area ◽  
Iucn Red List ◽  
Stem Diameter ◽  
Canopy Openness ◽  
Total N ◽  
Brunei Darussalam ◽  
White Sands

Bornean heath (Kerangas) forests are a unique and increasingly rare tropical forest ecosystem that remains little studied. We quantified tree floristic diversity inKerangasforests in the Tutong White Sands, Brunei Darussalam, and investigated the influence of soil and environmental variables on community composition. Six 20 m × 20 m plots were established, where all trees of ≥5 cm diameter at breast height (DBH) were identified and measured to determine stem diameter and basal area. We determined pH, gravimetric water content, and concentrations of total nitrogen (N) and phosphorus (P) in topsoil, as well as litter depth and percentage canopy openness. A total of 296 trees were recorded, representing 78 species in 59 genera and 38 families. Stem diameter, basal area, species richness, and species diversity differed significantly among the six plots. The NMDS ordination revealed that differences in tree community compositions were significantly associated with total N concentrations and percentage canopy openness. Despite the small sampling area, we recorded several Bornean endemic tree species (16/78 tree species; 20.5%), including several IUCN Red List endangered and vulnerable species. Our results illustrate the potentially high conservation value of theKerangasforests in the Tutong White Sands and highlight the urgent need to protect and conserve this area.

scholarly journals How Does Radial Growth of Water-Stressed Populations of European Beech (Fagus sylvatica L.) Trees Vary under Multiple Drought Events?

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Tamalika Chakraborty ◽  
Albert Reif ◽  
Andreas Matzarakis ◽  
Somidh Saha
Keyword(s):  
Soil Water ◽  
Fagus Sylvatica ◽  
Tree Growth ◽  
Radial Growth ◽  
Basal Area ◽  
European Beech ◽  
Canopy Openness ◽  
Fagus Sylvatica L ◽  
The Impact ◽  
Neighborhood Competition

European beech (Fagus sylvatica L.) trees are becoming vulnerable to drought, with a warming climate. Existing studies disagree on how radial growth varies in European beech in response to droughts. We aimed to find the impact of multiple droughts on beech trees’ annual radial growth at their ecological drought limit created by soil water availability in the forest. Besides, we quantified the influence of competition and canopy openness on the mean basal area growth of beech trees. We carried out this study in five near-natural temperate forests in three localities of Germany and Switzerland. We quantified available soil water storage capacity (AWC) in plots laid in the transition zone from oak to beech dominated forests. The plots were classified as ‘dry’ (AWC < 60 mL) and ‘less-dry’ (AWC > 60 mL). We performed dendroecological analyses starting from 1951 in continuous and discontinuous series to study the influence of climatic drought (i.e., precipitation-potential evapotranspiration) on the radial growth of beech trees in dry and less-dry plots. We used observed values for this analysis and did not use interpolated values from interpolated historical records in this study. We selected six drought events to study the resistance, recovery, and resilience of beech trees to drought at a discontinuous level. The radial growth was significantly higher in less-dry plots than dry plots. The increase in drought had reduced tree growth. Frequent climatic drought events resulted in more significant correlations, hence, increased the dependency of tree growth on AWC. We showed that the recovery and resilience to climatic drought were higher in trees in less-dry plots than dry plots, but it was the opposite for resistance. The resistance, recovery, and resilience of the trees were heterogeneous between the events of drought. Mean growth of beech trees (basal area increment) were negatively impacted by neighborhood competition and positively influenced by canopy openness. We emphasized that beech trees growing on soil with low AWC are at higher risk of growth decline. We concluded that changes in soil water conditions even at the microsite level could influence beech trees’ growth in their drought limit under the changing climate. Along with drought, neighborhood competition and lack of light can also reduce beech trees’ growth. This study will enrich the state of knowledge about the ongoing debate on the vulnerability of beech trees to drought in Europe.

Dispersal of Goeppertia marantifolia clonal offspring increases with greater canopy openness and larger plant size

2017 ◽  
Vol 33 (2) ◽  
pp. 107-113 ◽  
Author(s):  
David P. Matlaga ◽  
Rachel K. Snyder ◽  
Carol C. Horvitz
Keyword(s):  
Leaf Area ◽  
Light Availability ◽  
Plant Size ◽  
Dispersal Distance ◽  
Permanent Plots ◽  
Canopy Openness ◽  
Parent Plant ◽  
Analysis Model ◽  
Corcovado National Park ◽  
Positive Effect

Abstract:Many plants within the neotropical understorey produce both seeds and clonal offspring. Plant attributes (i.e. size) and variability in light can influence seed dispersal but it is not known if these factors influence the dispersal of clonal offspring. Our goal was to determine if canopy openness and plant size influence clonal-offspring dispersal of the herb Goeppertia marantifolia, which produces clonal bulbils on above-ground shoots. We monitored plants in permanent plots with varying levels of canopy openness in Corcovado National Park, Costa Rica. We recorded canopy openness, leaf area and the distance clonal offspring travelled from their parent plant (N = 283). Our path analysis model demonstrated that canopy openness had a strong positive effect on dispersal distance, while the association between clonal-offspring dispersal distance and parent plant leaf area was only weakly positive. On average, plants experiencing high canopy openness dispersed their clonal offspring further than plants under low canopy openness (124 cm vs. 79 cm, respectively). Contrary to studies on species that utilize rhizomes and stolons for clonal reproduction, we found that in this bulbil-producing species light availability is positively associated with clonal dispersal distance. Therefore, the influence of resource availability on spatial population dynamics of clonal species may be influenced by the species’ growth-form.

Spatial variation in CO2 efflux from the soil in a mature beech forest ecosystem.

2021 ◽  
Author(s):  
Yihan Cai ◽  
Takahiro Nishimura ◽  
Hideyuki Ida ◽  
Mitsuru Hirota
Keyword(s):  
Spatial Variation ◽  
Temporal Variation ◽  
Forest Ecosystem ◽  
Linear Regression Analysis ◽  
Basal Area ◽  
Beech Forest ◽  
Controlling Factors ◽  
Spatial And Temporal Variation ◽  
Canopy Openness ◽  
Co2 Efflux

&lt;p&gt;&amp;#160;Soil respiration (Rs) is the second largest carbon flux between the atmosphere and terrestrial ecosystem. Because of the large proportion, even small change in Rs would considerably impact the global carbon cycle. Therefore, it is important to accurately estimate Rs by taking its spatial and temporal variation into consideration. While the temporal variation of Rs and its controlling factors have been well-described, large unexplainable part still has been remained in the spatial variation of Rs especially in the forest ecosystems with complex structures. The objective of this study is to fill the knowledge gap about spatial variation of Rs and its controlling factors in a typical mature beech forest in Japan. Hypotheses of this study were, 1) Rs would show large spatial variation in the mature beech forest, 2) the spatial variation of Rs was mainly influenced by soil water content (SWC) and soil temperature (ST), 3) the two key factors were determined by the forest structures. This study was conducted in a 1- ha permanent study plot in the mature beech forest with significant gap-mosaic structures. To examine these hypotheses, Rs, SWC, ST and parameters related to forest structure, i.e. sum of basal area, diameter at breast height, number of trees, number of species within a radius of 5 m from the Rs measurement points, and canopy openness were measured at 121 points in different season between 2012 to 2013. In this study, all the measurements of Rs were conducted by using alkali-absorption technique.&lt;/p&gt;&lt;p&gt;&amp;#160;Coefficient of variation of Rs was between 25 - 28 % which was similar to that of SWC in all the measurements. The spatial variation of Rs was relatively higher in July, August and September than that in June and October. There was no significant relationship in the spatial variation between Rs and ST in all the measurements, meanwhile, Rs was well explained by SWC in measurements conducted in August, September and October. Multiple linear regression analysis indicated that canopy openness and sum of basal area showed significant positive and negative correlation with SWC, respectively. And canopy openness explained SWC much more than sum of basal area did. This result suggested that SWC, the key factor determined the spatial variation of Rs, cannot be only explained by stems distribution and their characteristics, but also canopy architecture in the forest ecosystem.&lt;/p&gt;

scholarly journals Similar understorey structure in spite of edaphic and floristic dissimilarity in Amazonian forests

2015 ◽  
Vol 45 (4) ◽  
pp. 393-404 ◽  
Author(s):  
Lassi SUOMINEN ◽  
Kalle RUOKOLAINEN ◽  
Timo PITKÄNEN ◽  
Hanna TUOMISTO
Keyword(s):  
Satellite Imagery ◽  
Forest Structure ◽  
Satellite Image ◽  
Light Availability ◽  
Floristic Composition ◽  
Structural Features ◽  
Canopy Openness ◽  
Understorey Plants ◽  
Amazonian Forests ◽  
Geological Formations

Forest structure determines light availability for understorey plants. The structure of lowland Amazonian forests is known to vary over long edaphic gradients, but whether more subtle edaphic variation also affects forest structure has not beenresolved. In western Amazonia, the majority of non-flooded forests grow on soils derived either from relatively fertile sediments of the Pebas Formation or from poorer sediments of the Nauta Formation. The objective of this study was to compare structure and light availability in the understorey of forests growing on these two geological formations. We measured canopy openness and tree stem densities in three size classes in northeastern Peru in a total of 275 study points in old-growth terra firme forests representing the two geological formations. We also documented variation in floristic composition (ferns, lycophytes and the palm Iriartea deltoidea) and used Landsat TM satellite image information to model the forest structural and floristic features over a larger area. The floristic compositions of forests on the two formations were clearly different, and this could also be modelled with the satellite imagery. In contrast, the field observations of forest structure gave only a weak indication that forests on the Nauta Formation might be denser than those on the Pebas Formation. The modelling of forest structural features with satellite imagery did not support this result. Our results indicate that the structure of forest understorey varies much less than floristic composition does over the studied edaphic difference.

Vegetation responses to conifer encroachment in a western Cascade meadow: a chronosequence approach

2007 ◽  
Vol 85 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Ryan D. Haugo ◽  
Charles B. Halpern
Keyword(s):  
Forest Structure ◽  
Vegetation Change ◽  
Light Availability ◽  
Basal Area ◽  
Tree Age ◽  
Long Term Effects ◽  
Conifer Encroachment ◽  
Forest Herbs ◽  
Meadow Species ◽  
Chronosequence Approach

Conifer invasion of mountain meadows is pervasive in western North America, but its consequences for plant composition and diversity have not been studied. We used a chronosequence approach to reconstruct temporal patterns of vegetation change in response to ~200 years of conifer encroachment of a dry, montane meadow in the western Cascade Range, Oregon. Tree age distributions, forest structure, light, and vegetation composition were determined for three hundred and fifty-six 10 m × 10 m samples representing a gradient from open meadow to old forest (>90 years). Nonmetric multidimensional scaling revealed strong turnover in species composition from open meadow to old forest. Ordination axes were highly correlated with light availability and density/basal area of encroaching grand fir, Abies grandis (Dougl. ex D. Don) Lindl., and lodgepole pine, Pinus contorta Dougl. ex Loud. Cover of meadow species declined steeply with establishment of A. grandis ; richness declined more gradually and extirpations of meadow species were rare. Forest herbs colonized within two decades of tree establishment and within 60–80 years dominated the understory flora. In contrast with meadow species, changes in richness and cover of forest herbs were weakly related to changes in forest structure. Rapid replacement of meadow by forest species and long-term effects of trees on soils may limit potential for restoration of these unique habitats.

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