Assessment of Disturbances across Forest Inventory Plots in the Southeastern United States for the Period 1995–2018

2019 ◽  
Vol 66 (2) ◽  
pp. 242-255 ◽  
Author(s):  
Santosh K Ojha ◽  
Kozma Naka ◽  
Luben D Dimov
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Forest Inventory ◽  
Stand Structure ◽  
Forest Type ◽  
Southeastern United States ◽  
Forest Types ◽  
Forest Inventory And Analysis ◽  
Silvicultural Treatments ◽  
Structure And Functions

Abstract Disturbances of varying frequency and intensity shape the species composition, stand structure, and functions of forests. This study assessed the frequency and distribution of disturbances caused by eight agents (insects, diseases, fire, animals, weather, other vegetation, human, and unknown) in the forests of the southeastern United States from 1995 to 2018. We used data from 88,722 inventory measurements of 33,531 plots from the USDA Forest Inventory and Analysis database to assess disturbance among different forest types and to different canopy strata. Disturbances were detected in approximately 14 percent of the plots, located mostly in pine-dominated forest types. Fire was the most frequent disturbance agent (occurring 6 percent of the time), followed by weather and animal agents. The agents that caused the highest mortality rate during the period for saplings were silvicultural treatments (8.6 percent), other vegetation (5.6 percent), and fire (4.4 percent), whereas for trees they were silvicultural treatments (9.8 percent), weather (1.9 percent) and insects (1.7 percent). The forest type that appeared to have been most affected by disturbances was longleaf–slash pine of the Coastal Plain. These results are useful for understanding the spatiotemporal distribution of disturbance events in different southeastern forest types and locations and for guiding forest management activities to mitigate potential impacts.

Selective herbicides for control of hen’s eyes (Ardisia crenata) in forests and natural areas

2019 ◽  
Vol 12 (4) ◽  
pp. 229-235
Author(s):  
Richard Cristan ◽  
Patrick J. Minogue ◽  
Stephen F. Enloe ◽  
Brent Sellers ◽  
Anna Osiecka
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Southeastern United States ◽  
High Rate ◽  
Natural Areas ◽  
Invasive Shrub ◽  
Herbicide Treatments

AbstractHen’s eyes (Ardisia crenata Sims) is a shade-tolerant invasive shrub displacing native understory in forests of the Coastal Plain of the southeastern United States. Few studies have explored herbicide effectiveness on A. crenata, with foliar applications of triclopyr amine or triclopyr ester typically referenced as the standard treatments. This study evaluated efficacy of eight foliar herbicide treatments and a nontreated check at three locations at 12 mo after the first treatment (12MAT1) and 12 mo after the second treatment (12MAT2) on established (greater than 8-cm high) and seedling (less than 8-cm high) A. crenata. Treatments were four triclopyr formulations: amine, ester, choline, and acid (all at 4.04 kg ae ha−1); imazamox (1.12 and 2.24 kg ae ha−1); flumioxazin (0.43 kg ai ha−1); and triclopyr amine plus flumioxazin (4.04 + 0.43 kg ae ha−1). At 12MAT1, triclopyr ester, the high rate of imazamox, and triclopyr acid resulted in greater control of established A. crenata than any other herbicide (68%, 66%, and 64%, respectively). At 12MAT2, all herbicides except flumioxazin resulted in some control of A. crenata. Triclopyr ester, triclopyr acid, and the high rate of imazamox provided 95%, 93%, and 92% control, respectively. Triclopyr choline did not perform as well as the acid or ester formulations, and the tank mix of flumioxazin and triclopyr amine did not improve control over triclopyr amine alone. This study identified triclopyr acid and imazamox (2.24 kg ae ha−1) as new options for A. crenata control and indicated variation in the performance among the four triclopyr formulations.

scholarly journals Early indications of drought impacts on forests in the southeastern United States

2015 ◽  
Vol 91 (04) ◽  
pp. 376-383 ◽  
Author(s):  
Michael K. Crosby ◽  
Zhaofei Fan ◽  
Martin A. Spetich ◽  
Theodor D. Leininger ◽  
Xingang Fan
Keyword(s):  
United States ◽  
Forest Type ◽  
Southeastern United States ◽  
Forest Health ◽  
Classification And Regression Tree ◽  
Future Research ◽  
Red Oak ◽  
White Oak ◽  
Cart Analysis ◽  
Crown Dieback

In the southeastern United States, drought can pose a significant threat to forests by reducing the amount of available water, thereby stressing trees. Destructive changes in crown conditions provide the first visible indication of a problem in a forested area, making it a useful indicator for problems within an ecosystem. Forest Health and Monitoring (FHM) and Palmer's Drought Severity Index (PDSI) data from 11 states in the southeastern United States were obtained in an effort to determine the role that drought, forest type, and ecoregion have in indicating differences in crown dieback. Analyses were conducted by species groups using classification and regression tree (CART) analysis. The greatest amount of total relative crown dieback occurred in red oak (18%), followed by other hardwoods (14%), and white oak (11%). Relative crown dieback varied by forest type and ecoregion with a relationship to drought in both red oak and white oak. This information will be useful for focusing future research and modeling efforts to predict forest health conditions affected by changing climate variables.

Characterizing Canopy Openness Across Large Forested Landscapes Using Spherical Densiometer and Smartphone Hemispherical Photography

2021 ◽  
Author(s):  
Katie L Beeles ◽  
Jordon C Tourville ◽  
Martin Dovciak
Keyword(s):  
United States ◽  
Large Range ◽  
Forest Type ◽  
High Elevation ◽  
Canopy Openness ◽  
Hemispherical Photography ◽  
Forest Types ◽  
Northeastern United States ◽  
Closed Canopy ◽  
The Right

Abstract Canopy openness is an important forest characteristic related to understory light environment and productivity. Although many methods exist to estimate canopy openness, comparisons of their performance tend to focus on relatively narrow ranges of canopy conditions and forest types. To address this gap, we compared two popular approaches for estimating canopy openness, traditional spherical densiometer and modern smartphone hemispherical photography, across a large range of canopy conditions (from closed canopy to large gaps) and forest types (from low-elevation broadleaf to high-elevation conifer forests) across four states in the northeastern United States. We took 988 field canopy openness measurements (494 per instrument) and compared them across canopy conditions using linear regression and t-tests. The extensive replication allowed us to quantify differences between the methods that may otherwise go unnoticed. Relative to the densiometer, smartphone photography overestimated low canopy openness (<10%) but it underestimated higher canopy openness (>10%), regardless of forest type. Study Implications We compared two popular ways of measuring canopy openness (smartphone hemispherical photography and spherical densiometer) across a large range of forest structures encountered in the northeastern United States. We found that, when carefully applied, the traditional spherical densiometer can characterize canopy openness across diverse canopy conditions (including closed canopies) as effectively as modern smartphone canopy photography. Although smartphone photography reduced field measurement time and complexity, it was more susceptible to weather than the densiometer. Although selection of the right method depends on study objectives, we provide a calibration for these two popular methods across diverse canopies.

Contemporary status, distribution, and trends of mixedwoods in the northern United States

2021 ◽  
Author(s):  
Lance A. Vickers ◽  
Benjamin Knapp ◽  
John M Kabrick ◽  
Laura S. Kenefic ◽  
Anthony W. D'Amato ◽  
...  
Keyword(s):  
United States ◽  
New England ◽  
Analysis Data ◽  
Specific Information ◽  
Forest Types ◽  
Forest Inventory And Analysis ◽  
Mixedwood Forests ◽  
Contemporary Status ◽  
Northern United States ◽  
Abundance And Distribution

As interest in managing and maintaining mixedwood forests in the northern United States (US) grows, so does the importance of understanding their abundance and distribution. We analyzed Forest Inventory and Analysis data for insights into mixedwood forests spanning 24 northern US states from Maine south to Maryland and westward to Kansas and North Dakota. Mixedwoods, i.e., forests with both hardwoods and softwoods present but neither exceeding 75-80% of composition, comprise more than 19 million hectares and more than one-quarter of the northern US forest. They are most common in the Adirondack-New England, Laurentian, and Northeast ecological provinces but also occur elsewhere in hardwood-dominated ecological provinces. These mixtures are common even within forest types nominally categorized as either hardwood or softwood. The most common hardwoods within those mixtures were species of Quercus and Acer and the most common softwoods were species of Pinus, Tsuga, and Juniperus. Although mixedwoods exhibited stability in total area during our analysis period, hardwood saplings were prominent, suggesting widespread potential for eventual shifts to hardwood dominance in the absence of disturbances that favor regeneration of the softwood component. Our analyses suggest that while most mixedwood plots remained mixedwoods, harvesting commonly shifts mixedwoods to either hardwood- or softwood-dominated cover types but more specific information is needed to understand the causes of these shifts.

scholarly journals Storm-event flow pathways in lower coastal plain forested watersheds of the southeastern United States

2014 ◽  
Vol 50 (10) ◽  
pp. 8265-8280 ◽  
Author(s):  
Michael P. Griffin ◽  
Timothy J. Callahan ◽  
Vijay M. Vulava ◽  
Thomas M. Williams
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Southeastern United States ◽  
Storm Event ◽  
Forested Watersheds ◽  
Flow Pathways ◽  
Event Flow ◽  
Lower Coastal Plain

scholarly journals Using Forest Inventory Data with Landsat 8 Imagery to Map Longleaf Pine Forest Characteristics in Georgia, USA

2019 ◽  
Vol 11 (15) ◽  
pp. 1803 ◽  
Author(s):  
John Hogland ◽  
Nathaniel Anderson ◽  
David L. R. Affleck ◽  
Joseph St. Peter
Keyword(s):  
United States ◽  
Forest Inventory ◽  
Forest Type ◽  
Longleaf Pine ◽  
Basal Area ◽  
Pinus Palustris ◽  
Machine Learning Algorithms ◽  
Landsat 8 ◽  
Inventory Data ◽  
Forest Inventory Data

This study improved on previous efforts to map longleaf pine (Pinus palustris) over large areas in the southeastern United States of America by developing new methods that integrate forest inventory data, aerial photography and Landsat 8 imagery to model forest characteristics. Spatial, statistical and machine learning algorithms were used to relate United States Forest Service Forest Inventory and Analysis (FIA) field plot data to relatively normalized Landsat 8 imagery based texture. Modeling algorithms employed include softmax neural networks and multiple hurdle models that combine softmax neural network predictions with linear regression models to estimate key forest characteristics across 2.3 million ha in Georgia, USA. Forest metrics include forest type, basal area and stand density. Results show strong relationships between Landsat 8 imagery based texture and field data (map accuracy > 0.80; square root basal area per ha residual standard errors < 1; natural log transformed trees per ha < 1.081). Model estimates depicting spatially explicit, fine resolution raster surfaces of forest characteristics for multiple coniferous and deciduous species across the study area were created and made available to the public in an online raster database. These products can be integrated with existing tabular, vector and raster databases already being used to guide longleaf pine conservation and restoration in the region.

scholarly journals Orange Cane Blotch of Commercial Blackberry in the Southeastern United States

2019 ◽  
Vol 20 (1) ◽  
pp. 67-69
Author(s):  
Frances B. Browne ◽  
Phillip M. Brannen ◽  
Harald Scherm ◽  
Marin T. Brewer ◽  
Susan B. Wilde ◽  
...  
Keyword(s):  
United States ◽  
Coastal Plain ◽  
Southeastern United States ◽  
Early Summer ◽  
Rdna Sequences ◽  
18S Rdna Sequences ◽  
Early Fall ◽  
Slow Growing ◽  
Geographical Locations ◽  
Preliminary Phylogenetic Analysis

Orange cane blotch affects commercial blackberry production in the southeastern United States, mainly in the Coastal Plain region. The causal agent is a slow-growing parasitic alga, Cephaleuros virescens, which has a wide host range. Disease development is linked to the biennial growth pattern of blackberry, whereby symptoms appear in the early fall and algal lesions expand throughout the winter, spring, and early summer of the following year. Preliminary phylogenetic analysis of 18S rDNA sequences suggests that blackberry isolates from different geographical locations cluster together and are genetically similar to each other and yet differ from isolates of C. virescens obtained from commercial blueberry.

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