Experimental Tree Mortality Does Not Induce Marsh Transgression in a Chesapeake Bay Low-Lying Coastal Forest

Transgression into adjacent uplands is an important global response of coastal wetlands to accelerated rates of sea level rise. “Ghost forests” mark a signature characteristic of marsh transgression on the landscape, as changes in tidal inundation and salinity cause bordering upland tree mortality, increase light availability, and the emergence of tidal marsh species due to reduced competition. To investigate these mechanisms of the marsh migration process, we conducted a field experiment to simulate a natural disturbance event (e.g., storm-induced flooding) by inducing the death of established trees (coastal loblolly pine, Pinus taeda) at the marsh-upland forest ecotone. After this simulated disturbance in 2014, we monitored changes in vegetation along an elevation gradient in control and treatment areas to determine if disturbance can lead to an ecosystem shift from forested upland to wetland vegetation. Light availability initially increased in the disturbed area, leading to an increase in biodiversity of vegetation with early successional grass and shrub species. However, over the course of this 5-year experiment, there was no increase in inundation in the disturbed areas relative to the control and pine trees recolonized becoming the dominant plant cover in the disturbed study areas. Thus, in the 5 years since the disturbance, there has been no overall shift in species composition toward more hydrophytic vegetation that would be indicative of marsh transgression with the removal of trees. These findings suggest that disturbance is necessary but not sufficient alone for transgression to occur. Unless hydrological characteristics suppress tree re-growth within a period of several years following disturbance, the regenerating trees will shade and outcompete any migrating wetland vegetation species. Our results suggest that complex interactions between disturbance, biotic resistance, and slope help determine the potential for marsh transgression.

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Changes in Physiological Functioning in Loblolly Pine Trees Undergoing Bark Beetle Simulated Mortality

Forest Science ◽

10.1093/forsci/fxy060 ◽

2018 ◽

Vol 65 (3) ◽

pp. 312-323

Author(s):

Nicole J Hornslein ◽

Courtney M Siegert ◽

Heidi J Renninger

Keyword(s):

Bark Beetle ◽

Loblolly Pine ◽

Tree Mortality ◽

Individual Tree ◽

Functional Changes ◽

Carbon And Nitrogen ◽

Pine Trees ◽

Nitrogen Concentrations ◽

Pinus Taeda L ◽

Beetle Damage

AbstractThe southeastern United States contains extensive loblolly pine (Pinus taeda L.) plantations at risk from bark beetle damage that can change ecosystem biogeochemical cycling. Functional changes in tree physiology have the potential to occur before visual evidence of mortality making them difficult to incorporate into ecosystem models. Therefore, we girdled loblolly pines to simulate bark beetle damage and measured physiological processes including sapflow rates, photosynthesis, litterfall, and needle nitrogen concentrations to determine the physiological changes occurring in trees undergoing mortality. We found that the girdling treatment took 5 months to significantly reduce sapflow rates but visual crown mortality occurred more than one year after girdling. Girdled pines had approximately 2.5 times lower water use than control pines and exhibited greater susceptibility to atmospheric water stress. Girdled and control pines had similar needle nitrogen concentrations and photosynthetic rates measured during the mortality year. However, more litterfall with higher nitrogen concentrations occurred in the mortality year than in the previous year, resulting in redistribution of carbon and nitrogen in the ecosystem. Overall, these data allow for better quantification of the effects of background disturbance levels and individual tree mortality on water, carbon, and nitrogen cycling within a loblolly pine ecosystem.

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Hurricane Katrina Impacts on Mississippi Forests

Southern Journal of Applied Forestry ◽

10.1093/sjaf/32.3.139 ◽

2008 ◽

Vol 32 (3) ◽

pp. 139-141 ◽

Cited By ~ 4

Author(s):

Sonja N. Oswalt ◽

Christopher Oswalt ◽

Jeffery Turner

Keyword(s):

Hurricane Katrina ◽

Loblolly Pine ◽

Public Interest ◽

Tree Mortality ◽

Gulf Coast ◽

Rapid Responses ◽

Pine Trees ◽

Systematic Sample ◽

The Impact ◽

Total Tree

Abstract Hurricane Katrina triggered public interest and concern for forests in Mississippi that required rapid responses from the scientific community. A uniform systematic sample of 3,590 ground plots were established and measured in 687 days immediately after the impact of Hurricane Katrina on the Gulf Coast. The hurricane damaged an estimated 521 million trees with more than 2.5-cm dbh and killed approximately 54 million trees statewide. Sixty-nine percent of tree mortality occurred in 17 counties in southeastern Mississippi, and 45% of trees killed were loblolly pine trees. Total tree mortality was less than 1% of the statewide population.

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Optimum Paraquat Treatments for Inducing Resin-Soaking in Slash and Loblolly Pines

Southern Journal of Applied Forestry ◽

10.1093/sjaf/7.1.31 ◽

1983 ◽

Vol 7 (1) ◽

pp. 31-33

Author(s):

Donald R. Roberts ◽

Kenneth W. Outcalt

Keyword(s):

South Carolina ◽

Loblolly Pine ◽

Tree Mortality ◽

Pinus Elliottii ◽

Slash Pine ◽

Savannah River ◽

Savannah River Plant ◽

Pine Trees ◽

Loblolly Pines ◽

Pinus Taeda L

Abstract Slash pine (Pinus elliottii Engelm. var elliottii) trees near Olustee, Florida, and loblolly pine (Pinus taeda L.) trees on the Savannah River Plant near Aiken, South Carolina, were treated with five concentrations of paraquat solution at three application volumes and by two methods to determine the optimum combination of concentration and volume for lightwood production in each species. Tree mortality was considerably higher with the tree injector method than with the bark-streak method. When tree mortality and yield are both considered, the optimum treatment for loblolly pine is 0.8 ml per injection with 6-percent paraquat or 0.5 ml of 7-percent paraquat per 25 mm of bark-streak wound. In slash pine trees, injections of 0.6 to 1 ml of 2-percent paraquat should give acceptable yields.

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Fertilizer responses of longleaf pine trees within a loblolly pine plantation: separating direct effects from competition effects

10.2737/srs-rp-48 ◽

2009 ◽

Author(s):

Peter H Anderson ◽

Kurt H. Johnsen

Keyword(s):

Loblolly Pine ◽

Longleaf Pine ◽

Direct Effects ◽

Pine Plantation ◽

Competition Effects ◽

Pine Trees

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Induced defenses of loblolly pine, Pinus taeda: potential impact on Dendroctonus frontalis within-tree mortality

Entomologia Experimentalis et Applicata ◽

10.1111/j.1570-7458.1988.tb02265.x ◽

1988 ◽

Vol 46 (1) ◽

pp. 39-46 ◽

Cited By ~ 10

Author(s):

T.D. Paine ◽

F.M. Stephen

Keyword(s):

Pinus Taeda ◽

Loblolly Pine ◽

Tree Mortality ◽

Dendroctonus Frontalis ◽

Induced Defenses ◽

Potential Impact

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Modeling the impact of thinning on height development of dominant and codominant loblolly pine trees

Annals of Forest Science ◽

10.1051/forest:2006015 ◽

2006 ◽

Vol 63 (4) ◽

pp. 349-354 ◽

Cited By ~ 27

Author(s):

Mahadev Sharma ◽

Michael Smith ◽

Harold E. Burkhart ◽

Ralph L. Amateis

Keyword(s):

Loblolly Pine ◽

Pine Trees ◽

The Impact

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

Canadian Journal of Forest Research ◽

10.1139/x10-156 ◽

2010 ◽

Vol 40 (11) ◽

pp. 2164-2174 ◽

Cited By ~ 12

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.

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Invasive Pine Tree Effects on Northern Coastal Scrub Structure and Composition

Invasive Plant Science and Management ◽

10.1614/ipsm-d-12-00044.1 ◽

2013 ◽

Vol 6 (2) ◽

pp. 231-242 ◽

Cited By ~ 4

Author(s):

Robert J. Steers ◽

Susan L. Fritzke ◽

Jen J. Rogers ◽

James Cartan ◽

Kaitlyn Hacker

Keyword(s):

Species Richness ◽

Plant Cover ◽

Ecological Impacts ◽

Tree Size ◽

Basal Diameter ◽

Monterey Pine ◽

Pine Tree ◽

Day Range ◽

Pine Trees ◽

The Impact

AbstractVegetation that becomes overtopped usually experiences a decrease in abundance or species richness. When an overtopping plant alters the physiognomy of the existing vegetation (e.g., trees invading a shrubland), ecosystem processes can also be dramatically altered. Worldwide, Monterey pine (Pinus radiata) cultivars have been planted in Mediterranean-like climates and are known to invade surrounding natural communities. Ecological impacts resulting from these invasions have been widely investigated; however, the effects from solitary pine trees on the vegetation they overtop are lacking. Furthermore, studies on the impact of P. radiata cultivars from the California floristic province, where P. radiata is native, do not exist. In coastal California, north of the present-day range of native P. radiata stands, cultivars of this species have invaded northern coastal scrub vegetation. To determine the impact of pine invasion on species richness and structure in this habitat, floristic surveys were conducted in 20 blocks that consisted of invaded and uninvaded plots. An invaded plot contained two subplots located under the canopy of an isolated pine tree, whereas a paired, uninvaded plot contained two subplots located in coastal scrub adjacent to each pine. Pine trees selected ranged in size from 2.8 to 119 cm (1.1 to 46.9 in) basal diameter. Our results demonstrate that understory native cover and species richness are negatively correlated with tree size. Understory exotic plant cover and richness of species other than P. radiata did not show any correlation with tree size, mainly because exotic plants had a very low abundance overall.

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