Nitrogen Fertilization, Stand Age, and Overstory Tree Species Impact the Herbaceous Layer in a Central Appalachian Hardwood Forest

Research Highlights: Herb-layer community composition, abundance, species richness, and Shannon–Wiener diversity index are shaped by nitrogen fertilization, disturbance history, and the overstory tree species in its immediate vicinity. Background and Objectives: While the herbaceous layer in deciduous forests is increasingly recognized for its importance in various aspects of forest ecosystem function, this study sought to describe the factors impacting the herbaceous layer. Specifically, this study’s objective was to quantify and compare herb-layer species composition, cover, and other community indices in watersheds with (a) different levels of N deposition, (b) different stand ages due to differing disturbance histories, and (c) different watershed aspects. This study also tested the hypothesis that herb-layer characteristics vary beneath tree species with contrasting nutrient dynamics (i.e., red and sugar maple). Materials and Methods: At the Fernow Experimental Forest in West Virginia (USA), the cover of all herb-layer species was recorded directly under nine red maple and nine sugar maple trees in each of four watersheds (WS): long-term fertilized WS3 and unfertilized WS7, both with a stand age of about 50 years, and two unmanaged watersheds with 110-year-old stands and opposite watershed aspects (south-facing WS10, north-facing WS13). Community composition and plot-level indices of diversity were evaluated with multivariate analysis and ANOVA for watershed-level differences, effects of the maple species, and other environmental factors. Results: In the fertilized watershed (WS3), herb-layer diversity indices were lower than in the unfertilized watershed of the same stand age (WS7). In the unfertilized watershed with the 50-year-old stand (WS7), herb-layer diversity indices were higher than in the watershed with the 110-year-old stand of the same watershed aspect (WS13). WS10 and WS13 had similar herb-layer characteristics despite opposite watershed aspects. The presence of sugar maple corresponded to higher cover and diversity indices of the herb-layer in some of the watersheds. Conclusions: Despite the limitations of a case study, these findings bear relevance to future forest management since the forest herb layer plays important roles in deciduous forests through its influence on nutrient cycling, productivity, and overstory regeneration.

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Developing Species-Age Cohorts from Forest Inventory and Analysis Data to Parameterize a Forest Landscape Model

International Journal of Forestry Research ◽

10.1155/2021/6650821 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Richard H. Odom ◽

W. Mark Ford

Keyword(s):

Tree Species ◽

Forest Inventory ◽

Sugar Maple ◽

Stand Age ◽

Forest Landscape ◽

Landscape Model ◽

Forest Stands ◽

Forest Inventory And Analysis ◽

Fort Drum ◽

Forest Landscape Model

Simulating long-term, landscape level changes in forest composition requires estimates of stand age to initialize succession models. Detailed stand ages are rarely available, and even general information on stand history often is lacking. We used data from USDA Forest Service Forest Inventory and Analysis (FIA) database to estimate broad age classes for a forested landscape to simulate changes in landscape composition and structure relative to climate change at Fort Drum, a 43,000 ha U.S. Army installation in northwestern New York. Using simple linear regression, we developed relationships between tree diameter and age for FIA site trees from the host and adjacent ecoregions and applied those relationships to forest stands at Fort Drum. We observed that approximately half of the variation in age was explained by diameter breast height (DBH) across all species studied (r2 = 0.42 for sugar maple Acer saccharum to 0.63 for white ash Fraxinus americana). We then used age-diameter relationships from published research on northern hardwood species to calibrate results from the FIA-based analysis. With predicted stand age, we used tree species life histories and environmental conditions represented by ecological site types to parameterize a stochastic forest landscape model (LANDIS-II) to spatially and temporally model successional changes in forest communities at Fort Drum. Forest stands modeled over 100 years without significant disturbance appeared to reflect expected patterns of increasing dominance by shade-tolerant mesophytic tree species such as sugar maple, red maple (Acer rubrum), and eastern hemlock (Tsuga canadensis) where soil moisture was sufficient. On drier sandy soils, eastern white pine (Pinus strobus), red pine (P. resinosa), northern red oak (Quercus rubra), and white oak (Q. alba) continued to be important components throughout the modeling period with no net loss at the landscape scale. Our results suggest that despite abundant precipitation and relatively low evapotranspiration rates for the region, low soil water holding capacity and fertility may be limiting factors for the spread of mesophytic species on excessively drained soils in the region. Increasing atmospheric temperatures projected for the region could alter moisture regimes for many coarse-textured soils providing a possible mechanism for expansion of xerophytic tree species.

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Prescribed fire alters structure and composition of a mid-Atlantic oak forest up to eight years after burning

Fire Ecology ◽

10.1186/s42408-021-00093-5 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Cody L. Dems ◽

Alan H. Taylor ◽

Erica A. H. Smithwick ◽

Jesse K. Kreye ◽

Margot W. Kaye

Keyword(s):

Prescribed Fire ◽

Forest Structure ◽

Tree Species ◽

Structural Changes ◽

The United States ◽

Tree Density ◽

Deciduous Forests ◽

Forest Composition ◽

In Fire ◽

Overstory Tree

Abstract Background Prescribed fire in Eastern deciduous forests has been understudied relative to other regions in the United States. In Pennsylvania, USA, prescribed fire use has increased more than five-fold since 2009, yet forest response has not been extensively studied. Due to variations in forest composition and the feedback between vegetation and fire, Pennsylvania deciduous forests may burn and respond differently than forests across the eastern US. We measured changes in forest structure and composition up to eight years after prescribed fire in a hardwood forest of the Ridge and Valley region of the Appalachian Mountains in central Pennsylvania. Results Within five years post fire, tree seedling density increased more than 72% while sapling density decreased by 90%, midstory density decreased by 46%, and overstory response varied. Following one burn in the mixed-oak unit, overstory tree density decreased by 12%. In the aspen–oak unit, where pre-fire harvesting and two burns occurred, overstory tree density increased by 25%. Not all tree species responded similarly and post-fire shifts in species relative abundance occurred in sapling and seedling size classes. Abundance of red maple and cherry species decreased, whereas abundance of sassafras, quaking aspen, black oak, and hickory species increased. Conclusions Forest composition plays a key role in the vegetation–fire relationship and localized studies are necessary to measure forest response to prescribed fire. Compositional shifts in tree species were most pronounced in the aspen–oak unit where pre-fire overstory thinning and two prescribed fires were applied and significant structural changes occurred in all stands after just one burn. Increases in fire-tolerant tree species combined with reductions in fire-intolerant species highlight the role of prescribed fire in meeting management objectives such as altering forest structure and composition to improve game habitat in mid-Atlantic hardwood forests.

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Effects of clearcut logging and tree species composition on the diversity and community composition of epigeous fruit bodies formed by ectomycorrhizal fungi

Canadian Journal of Botany ◽

10.1139/b06-045 ◽

2006 ◽

Vol 84 (6) ◽

pp. 966-980 ◽

Cited By ~ 43

Author(s):

Daniel M. Durall ◽

Sharmin Gamiet ◽

Suzanne W. Simard ◽

Lenka Kudrna ◽

Stacey M. Sakakibara

Keyword(s):

Species Composition ◽

Community Composition ◽

Tree Species ◽

Forest Tree ◽

Douglas Fir ◽

Stand Age ◽

Fungal Community Composition ◽

Mixed Forests ◽

Tree Species Composition ◽

Russula Brevipes

The objective of this study was to examine the effects of stand age and tree species composition on the abundance, diversity, and community composition of epigeous fruit bodies formed by ectomycorrhizal (ECM) fungi in the Interior Cedar Hemlock zone of British Columbia. Fruit bodies were collected and identified in May, June, August, September, and October of 1996, 1997, 1998, and 1999 from transects located in new (5 year old) plantations and mature (75–125 year old) wild forests composed of relatively pure Betula papyrifera Marsh. (paper birch), relatively pure Pseudotsuga menziesii var. glauca (Beissn.) Franco (interior Douglas-fir), and mixtures of the two tree species. A total of 187 fungal taxa were collected during the study, of which 185 occurred in mature forests and only 17 occurred in the plantations. Thirty-four taxa were unique to mature predominantly birch forests, 35 were unique to mature predominantly Douglas-fir forests, 17 were unique to mixed mature forests, and 68 taxa were found in all three mature forest types. The abundance of fruit bodies in mature forests varied widely among sampling years and generally increased with annual precipitation. ECM species richness differed between stand ages but not among forest compositions in both plantations and mature forests. Lactarius glyciosmus , Hygrophorus eburneus var. eburneus , and Cortinarius armillatus were more abundant in mature birch than mature Douglas-fir forests. Lactarius torminosus , Leccinum scabrum var. scabrum , and Rozites caperatus were also found predominantly in mature birch and mixed forests, whereas Gomphidius subroseus was more abundant in Douglas-fir forests than in birch and mixed mature forests. Russula brevipes was also found predominantly in mature Douglas-fir and mixed forests. Our results indicate that clearcutting has a profound effect on abundance and composition of ECM fruit bodies, and that changes in forest tree species composition may lead to shifts in ECM fungal community composition.

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Climate resilience through natural regeneration in degraded natural forests of south-eastern hilly region of Bangladesh

Bangladesh Journal of Botany ◽

10.3329/bjb.v48i3.47720 ◽

2019 ◽

Vol 48 (3) ◽

pp. 417-425

Author(s):

Md Khayrul Alam Bhuiyan ◽

Md Akhter Hossain ◽

Abdul Kadir Ibne Kamal ◽

Mohammed Kamal Hossain ◽

Mohammed Jashimuddin ◽

...

Keyword(s):

Tree Species ◽

Natural Regeneration ◽

Diversity Indices ◽

Acacia Auriculiformis ◽

Quantitative Structure ◽

Natural Forests ◽

Climate Resilience ◽

Hilly Region ◽

Major Cluster ◽

Ecological Dominance

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.

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Storage of Nutrients In Different Components of Selected Tree Species, Shrubs and Herb Layer Under the Tree Species

International Journal of Scientific Research ◽

10.15373/22778179/july2014/147 ◽

2012 ◽

Vol 3 (7) ◽

pp. 469-471

Author(s):

Dr.Beena Sharma ◽

Keyword(s):

Tree Species ◽

Herb Layer

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Tree Diversity Conservation Initiatives in Sacred Groves of Kathmandu Valley, Nepal

Nepal Journal of Science and Technology ◽

10.3126/njst.v19i1.29768 ◽

2020 ◽

Vol 19 (1) ◽

pp. 60-68

Author(s):

Laxmi Joshi Shrestha ◽

Mohan Devkota ◽

Bhuvan Keshar Sharma

Keyword(s):

Tree Species ◽

Management System ◽

Survey Methods ◽

Belief Systems ◽

Decisive Role ◽

Diversity Indices ◽

Kathmandu Valley ◽

Sacred Grove ◽

Sacred Groves ◽

The Government

The study was conducted in two sacred groves of Kathmandu Valley, Pashupati Sacred Grove, and Bajrabarahi Sacred Grove, aiming to analyze the diversity of tree species and their role in conserving biodiversity. Parallel transects with concentric circular plot survey methods were applied for data collection. During the study, 23 tree species belonging to 22 genera and 15 families were recorded in Pashupati sacred grove, whereas only 19 tree species belonging to 16 genera and 13 families were recorded from Bajrabarahi Sacred Grove. The Shannon-Weiner diversity indices were higher (H=1.91) in Pashupati Sacred Grove compared to Bajrabarahi Sacred Grove, with 1.80 Shanon-Weiner Indices. Three types of forest were recorded from Pashupati Sacred Grove, namely the Schima-Pyrus forest, Myrsine-Persea forest, and Quercus-Myrsine forest, and only one Neolitsiacuipala forest from Bajrabarahi Sacred Grove. The sacred grove is one of the pioneers and community-based management regimes of the forest resource management system. It plays a decisive role in biodiversity conservation as it associated with many taboos and belief systems, thus providing a better opportunity for conservation compared to that of the government management system.

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Growth responses of seven major co-occurring tree species of the northeastern United States to elevated CO2

Canadian Journal of Forest Research ◽

10.1139/x90-195 ◽

1990 ◽

Vol 20 (9) ◽

pp. 1479-1484 ◽

Cited By ~ 99

Author(s):

F. A. Bazzaz ◽

J. S. Coleman ◽

S. R. Morse

Keyword(s):

Tree Species ◽

Sugar Maple ◽

Growth Enhancement ◽

Black Cherry ◽

Red Maple ◽

Growth Responses ◽

White Pine ◽

American Beech ◽

Harvard Forest ◽

Paper Birch

We examined how elevated CO2 affected the growth of seven co-occurring tree species: American beech (Fagusgrandifolia Ehrh.), paper birch (Betulapapyrifera Marsh.), black cherry (Prunusserotina Ehrh.), white pine (Pinusstrobus L.), red maple (Acerrubrum L.), sugar maple (Acersaccharum Marsh.), and eastern hemlock (Tsugacanadensis (L.) Carr). We also tested whether the degree of shade tolerance of species and the age of seedlings affected plant responses to enhanced CO2 levels. Seedlings that were at least 1 year old, for all species except beech, were removed while dormant from Harvard Forest, Petersham, Massachusetts. Seeds of red maple and paper birch were obtained from parent trees at Harvard Forest, and seeds of American beech were obtained from a population of beeches in Nova Scotia. Seedlings and transplants were grown in one of four plant growth chambers for 60 d (beech, paper birch, red maple, black cherry) or 100 d (white pine, hemlock, sugar maple) under CO2 levels of 400 or 700 μL•L−1. Plants were then harvested for biomass and growth determinations. The results showed that the biomass of beech, paper birch, black cherry, sugar maple, and hemlock significantly increased in elevated CO2, but the biomass of red maple and white pine only marginally increased in these conditions. Furthermore, there were large differences in the magnitude of growth enhancement by increased levels of CO2 between species, so it seems reasonable to predict that one consequence of rising levels of CO2 may be to increase the competitive ability of some species relative to others. Additionally, the three species exhibiting the largest increase in growth with increased CO2 concentrations were the shade-tolerant species (i.e., beech, sugar maple, and hemlock). Thus, elevated CO2 levels may enhance the growth of relatively shade-tolerant forest trees to a greater extent than growth of shade-intolerant trees, at least under the light and nutrient conditions of this experiment. We found no evidence to suggest that the age of tree seedlings greatly affected their response to elevated CO2 concentrations.

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Tree Species Diversity, Composition and Aboveground Biomass Across Dry Forest Land-Cover Types in Coastal Ecuador

Tropical Conservation Science ◽

10.1177/1940082921995415 ◽

2021 ◽

Vol 14 ◽

pp. 194008292199541

Author(s):

Xavier Haro-Carrión ◽

Bette Loiselle ◽

Francis E. Putz

Keyword(s):

Species Diversity ◽

Land Cover ◽

Community Composition ◽

Aboveground Biomass ◽

Tree Species ◽

Dry Forest ◽

Stem Density ◽

Tree Species Diversity ◽

Land Cover Types ◽

Schizolobium Parahyba

Tropical dry forests (TDF) are highly threatened ecosystems that are often fragmented due to land-cover change. Using plot inventories, we analyzed tree species diversity, community composition and aboveground biomass patterns across mature (MF) and secondary forests of about 25 years since cattle ranching ceased (SF), 10–20-year-old plantations (PL), and pastures in a TDF landscape in Ecuador. Tree diversity was highest in MF followed by SF, pastures and PL, but many endemic and endangered species occurred in both MF and SF, which demonstrates the importance of SF for species conservation. Stem density was higher in PL, followed by SF, MF and pastures. Community composition differed between MF and SF due to the presence of different specialist species. Some SF specialists also occurred in pastures, and all species found in pastures were also recorded in SF indicating a resemblance between these two land-cover types even after 25 years of succession. Aboveground biomass was highest in MF, but SF and Tectona grandis PL exhibited similar numbers followed by Schizolobium parahyba PL, Ochroma pyramidale PL and pastures. These findings indicate that although species-poor, some PL equal or surpass SF in aboveground biomass, which highlights the critical importance of incorporating biodiversity, among other ecosystem services, to carbon sequestration initiatives. This research contributes to understanding biodiversity conservation across a mosaic of land-cover types in a TDF landscape.

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