Comparing power among three sampling methods for monitoring forest vegetation

2008 ◽  
Vol 38 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Sarah E. Johnson ◽  
E. L. Mudrak ◽  
E. A. Beever ◽  
S. Sanders ◽  
D. M. Waller
Keyword(s):  
National Parks ◽  
Basal Area ◽  
Forest Vegetation ◽  
Forest Understory ◽  
Individual Species ◽  
Sampling Effort ◽  
Understory Composition ◽  
Tree Communities ◽  
Understory Communities ◽  
Composite Variables

We compared three methods of sampling forest vegetation for their ability to reliably estimate changes in species richness, plant abundance, and overstory basal area and composition. Methods include the US Forest Service’s Forest Inventory and Analysis (FIA) method and two other methods being considered for use in monitoring National Parks in the Northern Great Lakes ecoregion. All methods were successful at detecting changes in composite variables but lacked sufficient enough power to detect a 20% change in the abundance of most individual species. All three methods had high power for detecting changes in overstory tree communities but differed greatly in their ability to track shifts in understory composition and diversity. Although complete walk-through surveys of all species present provided adequate power for tracking changes in diversity, sampling only 12 ground layer quadrats limited the power of the FIA method. Methods that sample the understory more intensively provide a better balance of sampling effort and provide higher power to detect changes in forest understory communities. Aggregating data across sites of similar habitat also provides more powerful estimates of change.

scholarly journals Accuracy and Precision of 10 Year Predictions for Forest Vegetation Simulator—Lake States

2000 ◽  
Vol 17 (2) ◽  
pp. 62-70 ◽  
Author(s):  
Seal J. Canavan ◽  
Carl W. Ramm
Keyword(s):  
Basal Area ◽  
Forest Vegetation ◽  
Individual Species ◽  
Diameter Growth ◽  
Forest Vegetation Simulator ◽  
White Oak ◽  
Individual Tree ◽  
Projection System ◽  
Accuracy And Precision ◽  
Lake States

Abstract This study is a followup to the 5 yr validation of the Lake States TWIGS (The Woodsman's Ideal Growth Projection System) projection system by Guertin and Ramm (1996). Accuracy and precision of 10 yr diameter growth, basal area growth and mortality predicted by the Lake States variant of the Forest Vegetation Simulator (FVS) were evaluated for seven upland hardwood species in Michigan's northern Lower Peninsula. The robustness of FVS predictions was examined by varying projection cycle length and the level of detail of stand and tree-information included in growth projections.The data used in the analysis consisted of individual tree measurements from 44 stands across 10 ecological land type phases in the Manistee National Forest. FVS-Lake States was found to consistently overpredict 10 yr diameter growth across all seven species. Ten year diameter growth was predicted within ±0.5 in. across all projections for nearly all species and size-class combinations for the seven species examined. Basal area and mortality errors were less consistent. Mean errors for trees per acre ranged from -24 for red maple to +14 for white oak. These errors led to a consistent overprediction of basal area per acre for all species combined, while prediction errors for individual species were less than ±8 ft²/ac. Precision was variable, especially for mortality predictions. The most accurate predictions were obtained with longer cycle lengths and with projections using tree diameter, tree height, and crown ratio along with site index and individual tree past diameter growth. North. J. Appl. For. 17(2):62-70.

Floristic Variation of Tree Communities and Their Association with Soil Properties in Pulau Jerejak, Penang, Peninsular Malaysia

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi
Keyword(s):  
Tree Species ◽  
Diversity Index ◽  
Basal Area ◽  
Peninsular Malaysia ◽  
Importance Value ◽  
Conservation Action ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Tree Communities ◽  
Floristic Variation

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

scholarly journals Diferentes distúrbios antrópicos na paisagem podem influenciar padrões florísticos e estruturais da Mata Atlântica?

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Elisa Morais Paschoal ◽  
Arthur Duarte Vieira ◽  
Thiago José Ornelas Otoni ◽  
Aglaia Maciel Gripp ◽  
Jessica Pereira Freire ◽  
...  
Keyword(s):  
Structural Component ◽  
Basal Area ◽  
Floristic Composition ◽  
Semideciduous Forest ◽  
Floristic Similarity ◽  
Alpha And Beta Diversity ◽  
Intermediate Disturbance ◽  
Tree Communities ◽  
Environmental Variations ◽  
Tree Component

This study aimed to describe and compare the floristic and structural component of the tree component, as well as the alpha and beta diversity, as well as the floristic similarity of a remnant of Semideciduous Forest. The tree vegetation was sampled at two edges in contact with pasture (BP) and coffee growing (BC), and inside the fragment (INT). 2.840 individuals were sampled, identified in 56 families, 144 genera and 271 species (94 BC, 128 BP and 178 INT). The border stretches were characterized by higher density and smaller basal area than the interior, indicating the occurrence of disturbances. The variations in the structural floristic composition of the tree communities wereinfluenced by regional and local environmental variations, as well as the historical use of the area, according to Niche and Intermediate Disturbance Theories.

scholarly journals The legacy of fire: long-term changes to the forest understory from periodic burns in a New England oak-hickory forest

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Caroline G. Borden ◽  
Marlyse C. Duguid ◽  
Mark S. Ashton
Keyword(s):  
New England ◽  
Plant Density ◽  
Forest Understory ◽  
Tree Seedlings ◽  
Floristic Diversity ◽  
Plant Structure ◽  
Burn Treatment ◽  
Prescribed Burns ◽  
Southern New England ◽  
Understory Composition

Abstract Background Over the last century, fire exclusion has caused dramatic structural and compositional changes to southern New England forests, highlighting the need to reintroduce fires into the historically pyrogenic landscape to study the response. We investigated the effects of a single overstory thinning and midstory removal to create an open oak-hickory woodland structure, followed by repeated prescribed burns. We hypothesized that burning would create greater floristic diversity comprising fire-tolerant woody regeneration and shade-intolerant herbaceous flora. We followed shifts in plant structure, composition, and diversity over a 23-year period, using a before-after-control-impact design with data collected once prior to burning and twice after burn treatments had begun and with soil samples collected after nearly 20 years of burning. Results We observed a dense ingrowth of saplings on unburned plots that were largely absent from burned plots and a shift in midstory composition to favor mesic sweet birch (Betula lenta L.) in the unburned treatment, as opposed to the hickories (Carya Nutt. spp.) and oaks (Quercus L. spp.) that dominated the burned treatment. Burning resulted in a significantly greater density, richness, Shannon diversity, and evenness of understory vegetation (forbs, shrubs, tree seedlings). These four measures remained high on burned plots, despite a decrease in both floristic diversity and evenness on unburned plots and a reduction in unburned site-level richness. Understory composition varied significantly by year and burn treatment, with unburned plots largely characterized by shade-tolerant species while burned plots showed an enhanced abundance of heliophilic plants. Conclusions Our results suggest that periodic burning increases nutrient microsite heterogeneity and periodically maintains greater understory light, both of which in turn increase understory plant density and diversity and cause a shift in understory composition. This study shows that repeated prescribed burns in an open New England woodland have lasting structural and compositional effects capable of restoring pre-settlement, pyrogenic vegetation patterns.

scholarly journals Disturbance intensity, disturbance extent and ocean climate modulate kelp forest understory communities

2020 ◽  
Vol 651 ◽  
pp. 57-69
Author(s):  
T Wernberg ◽  
M Couraudon-Réale ◽  
F Tuya ◽  
M Thomsen
Keyword(s):  
Functional Groups ◽  
Kelp Forest ◽  
Forest Understory ◽  
Small Scale ◽  
Kelp Forests ◽  
Ocean Climate ◽  
Disturbance Regimes ◽  
Disturbance Intensity ◽  
Control Community ◽  
Understory Communities

Disturbances often control community structure by removing large dominant species, allowing new species to colonize. Disturbances vary in intensity and extent, and their effects on resident communities can depend on local environmental conditions. We tested the effects of disturbance intensity and extent on different functional groups of understory species in kelp forests at 4 locations along an ocean climate gradient in Western Australia. We hypothesized that, compared to intact canopies, increasing disturbance intensities (50 and 100% of kelp removal) and extents (2, 4 and 8 m diameter) would promote light-dependent competitors (turf, foliose, articulated coralline and fucoid seaweeds) at the expense of less light-dependent functional groups (invertebrates and encrusting seaweeds). We also hypothesized that these effects would be most pronounced at warmer relative to cooler locations, where metabolic and ecological rates are faster. The first hypothesis was supported; light-dependent understory groups (turfs, in particular) increased, while less light-dependent groups (crusts in particular) decreased with increasing disturbance regimes. However, the second hypothesis was not supported; even though understory communities differed between locations and turf covers were highest at the warmest location, we found no significant interactions between locations and disturbance regimes. Importantly, our results revealed that even small-scale partial canopy loss can have significant effects on kelp-associated communities. The implied community-wide, density-dependent effects have implications for the management and conservation of kelp forests, because restoration of ecological functions must also consider the density of kelp forests, not simply their presence or absence.

scholarly journals Did the Ambient Ozone Affect Stem Increment of Scots Pines (Pinus sylvestrisL.) on Territories under Regional Pollution Load? Step III of Lithuanian Studies

2007 ◽  
Vol 7 ◽  
pp. 58-66 ◽  
Author(s):  
Algirdas Augustaitis ◽  
Ingrida Augustaitiene ◽  
Gintautas Cinga ◽  
Juozapas Mazeika ◽  
Romualdas Deltuvas ◽  
...  
Keyword(s):  
National Parks ◽  
Negative Impact ◽  
Basal Area ◽  
Pollution Load ◽  
Integrated Monitoring ◽  
Ambient Ozone ◽  
Pine Tree ◽  
Crown Defoliation ◽  
The Impact ◽  
Stem Increment

This study aimed to explore if changes in stem increment of Scots pines (Pinus sylvestrisL.) could be related to changes in ambient ozone concentration when the impact of tree dendrometric parameters (age, diameter) and crown defoliation are accounted for. More than 200 dominant and codominant trees from 12 pine stands, for which crown defoliation had been assessed since 1994, were chosen for increment boring and basal area increment computing. Stands are located in Lithuanian national parks, where since 1994–95 Integrated Monitoring Stations have been operating. Findings of the study provide statistical evidence that peak concentrations of ambient ozone (O3) can have a negative impact on pine tree stem growth under field conditions where O3exposure is below phytotoxic levels.

scholarly journals A Phylogenetic Perspective on the Individual Species-Area Relationship in Temperate and Tropical Tree Communities

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e63192 ◽  
Author(s):  
Jie Yang ◽  
Nathan G. Swenson ◽  
Min Cao ◽  
George B. Chuyong ◽  
Corneille E. N. Ewango ◽  
...  
Keyword(s):  
Tropical Tree ◽  
Individual Species ◽  
Tree Communities ◽  
Species Area ◽  
Phylogenetic Perspective ◽  
Species Area Relationship ◽  
The Individual

Status, diversity and trends of the bird communities in Volcanoes National Park and surrounds, Rwanda

2019 ◽  
Vol 30 (1) ◽  
pp. 1-20 ◽  
Author(s):  
MIA A. DERHÉ ◽  
DEO TUYISINGIZE ◽  
WINNIE ECKARDT ◽  
FAIDA EMMANUEL ◽  
TARA STOINSKI
Keyword(s):  
National Parks ◽  
National Park ◽  
Mixed Forest ◽  
Basal Area ◽  
Bird Community ◽  
Bird Communities ◽  
Population Pressure ◽  
Bird Diversity ◽  
Albertine Rift ◽  
1960S And 1970S

SummaryThe Volcanoes National Park (VNP) in Rwanda, part of the Virunga massif in the Albertine Rift region, boasts some of Rwanda’s best remaining natural vegetation and is home to many endangered and endemic species. The park has suffered from high levels of degradation and destruction, reducing in size by 50% during the 1960s and 1970s, and remains under threat from illegal activities, human population pressure and climate change. This study is the first to investigate the status and trends of bird communities in the VNP, using a multi-year dataset. We use a five-year dataset, totalling over 3,200 point-counts, both within and around the VNP, to assess the conservation value of the VNP for birds in comparison with other national parks and non-protected areas. We assess bird communities and population trends within and around the parks and identify important habitat factors for birds within the VNP. We found that the VNP hosts a unique bird community compared to other localities, with several Albertine Rift endemics and threatened species occurring in the VNP. Hagenia/ Hypericum woodland, herbaceous vegetation, brush ridge and mixed forest host the highest levels of bird diversity in the VNP, whilst the park’s waterbodies provide key habitat for the endangered Albertine Rift endemic Grauer’s Swamp-warbler (Bradypterus graueri). Elevation had a negative effect on bird diversity in the VNP, whilst the basal area of dead trees, Hagenia and vines had a positive effect. Both inside and outside the VNP, there was a significant decline in abundance and species richness over the sampling years; however, we advocate for further monitoring to confirm these trends. Based on our findings, we recommend effective, targeted management of key habitats for birds within the park, including those identified in this study, in order to mitigate bird declines and conserve the unique bird communities in the VNP.

Growth of Uneven-Aged Stands in New York's Adirondack Mountains

1987 ◽  
Vol 4 (3) ◽  
pp. 136-139
Author(s):  
Thomas J. Temple ◽  
Ralph D. Nyland ◽  
Philip J. Craul
Keyword(s):  
Basal Area ◽  
Community Type ◽  
Individual Species ◽  
Forest Site ◽  
Adirondack Mountains ◽  
Soil Series ◽  
Annual Increment ◽  
Periodic Treatment ◽  
Community Types ◽  
Species Groups

Abstract Prediction equations are presented for total standing volume and periodic annual increment among unevenaged stands in New York's Adirondacks. These use stand basal area, plus selected physical site and vegetal characteristics of the stand. Few plots located across a range of community types or soil series differed significantly in volume increment, suggesting that neither the community type nor soil series provides a reliable basis for forest site productivity classification. Hardwoods grow better than conifers on the deeper less podzolized soils, and individual species or species groups grow differently from one community type to another. Yet, the superior growth of one tends to compensate for the mediocre performance of others within some community types, resulting in similar levels of total stand growth between communities. Findings indicate which species to favor in marking different stands for periodic treatment. North. J. Appl. For. 4:136-139, Sept. 1987.

scholarly journals Tree structure and richness in an Atlantic Forest fragment: distance from anthropogenic and natural edges

2009 ◽  
Vol 33 (6) ◽  
pp. 1123-1132 ◽  
Author(s):  
Maíra Taquiguthi Ribeiro ◽  
Flavio Nunes Ramos ◽  
Flavio Antonio Maës Dos Santos
Keyword(s):  
Atlantic Forest ◽  
Rio De Janeiro ◽  
Basal Area ◽  
The State ◽  
Forest Fragment ◽  
Dead Trees ◽  
Tree Communities ◽  
Standing Dead ◽  
Total Study Area ◽  
Tree Branch

Approximately 7.2% of the Atlantic rainforest remains in Brazil, with only 16% of this forest remaining in the State of Rio de Janeiro, all of it distributed in fragments. This forest fragmentation can produce biotic and abiotic differences between edges and the fragment interior. In this study, we compared the structure and richness of tree communities in three habitats - an anthropogenic edge (AE), a natural edge (NE) and the fragment interior (FI) - of a fragment of Atlantic forest in the State of Rio de Janeiro, Brazil (22°50'S and 42°28'W). One thousand and seventy-six trees with a diameter at breast height > 4.8 cm, belonging to 132 morphospecies and 39 families, were sampled in a total study area of 0.75 ha. NE had the greatest basal area and the trees in this habitat had the greatest diameter:height allometric coefficient, whereas AE had a lower richness and greater variation in the height of the first tree branch. Tree density, diameter, height and the proportion of standing dead trees did not differ among the habitats. There was marked heterogeneity among replicates within each habitat. These results indicate that the forest interior and the fragment edges (natural or anthropogenic) do not differ markedly considering the studied parameters. Other factors, such as the age from the edge, type of matrix and proximity of gaps, may play a more important role in plant community structure than the proximity from edges.

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