scholarly journals Short-Term Effects of Silvicultural Treatments on Microsite Heterogeneity and Plant Diversity in Mature Tennessee Oak-Hickory Forests

2006 ◽  
Vol 23 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Samuel W. Jackson ◽  
Craig A. Harper ◽  
David S. Buckley ◽  
Bradley F. Miller

Abstract Growing emphasis on sustainability has increased the demand for information on effects of forest management on species diversity. We investigated the hypothesis that plant diversity is a function of microsite heterogeneity by documenting plant diversity and heterogeneity in canopy cover, light, and soil moisture produced by four silvicultural treatments during the first growing season following treatment: prescribed burning, wildlife retention cut with prescribed burning, wildlife retention cut, and shelterwood cutting. Treatments and controls were randomly assigned within four relatively undisturbed, 70–90-year-old oak-hickory stands. Heterogeneity in canopy cover and photosynthetically active radiation was greatest after shelterwood cutting, whereas the wildlife retention cut resulted in less removal of canopy trees and a smaller increase in heterogeneity of these factors. The addition of prescribed burning enhanced the effects of the wildlife retention cut. Prescribed burning alone had the least impact on heterogeneity of these factors. Soil moisture variability appeared to be independent of treatments. Shelterwood cutting increased first-year herbaceous plant diversity, and this increase was likely due, in part, to increased heterogeneity in canopy cover, light, and seedbed condition. These first-year results partially support the hypothesis that plant diversity is a function of microsite diversity in these forests. Long-term monitoring is underway.

2010 ◽  
Vol 3 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Robert E. Loeb ◽  
Jesse Germeraad ◽  
Travis Treece ◽  
Daniel Wakefield ◽  
Steve Ward

AbstractAmur honeysuckle recovery following treatments annually and only in 1-year, during 2002 to 2009, was compared in the forests of Radnor Lake State Natural Area in Nashville, TN. Annual treatment areas had significantly lower mean Amur honeysuckle plant counts than 1-yr treatment areas for both ≤ 1 m (3.3 ft) and > 1 m plant heights and on both sloped and level areas, except for plants ≤ 1 m tall on level areas, which most likely indicated more soil moisture increasing seedling establishment and root sprouting in the first year after treatment. The significant, positive Pearson's product moment correlations for Amur honeysuckle counts of plants ≤ 1 m tall, with arboreal basal area and with canopy species diversity in the level areas of the annual treatment plots, were also most likely evidence for the importance of greater soil moisture during the first year after treatment for greater Amur honeysuckle recovery. For land managers interested in native vegetation restoration, guidance is provided to plan for long-term, invasive plant species treatment and recovery monitoring.


Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Joseph M. DiTomaso ◽  
Guy B. Kyser ◽  
Marla S. Hastings

Two separate open grassland areas within Sugarloaf Ridge State Park, Sonoma County, CA, were burned for three consecutive years (1993–1995 [Site A] and 1995–1997 [Site B]) for control of yellow starthistle. Burns were conducted in late June to early July following seed dispersal and senescence of desirable grasses and forbs but prior to viable seed production in yellow starthistle. After the first year burn, there was no significant reduction in yellow starthistle cover the following spring and summer. Despite the lack of control, the first year burn reduced the yellow starthistle soil seedbank by 74% and the number of seedlings the following spring by 83%. However, total plant diversity and species richness increased dramatically in the burned areas. This was due primarily to an increase in the number of native broadleaf species. A second burn the next summer (1995–1997 site) reduced seedbank, seedling density, and summer vegetative cover the following year by 94, 92, and 85%, respectively, while maintaining significantly higher native plant cover and richness. A third consecutive summer burn decreased yellow starthistle seedbank and seedling density by 96, 98, and 85%, respectively, in the 1995–1997 burn site. Three consecutive years of burning in the 1993–1995 site reduced yellow starthistle seedbank and seedling density by over 99% and summer vegetative cover by 91%. These results indicate that prescribed burning can be an effective tool for the management of yellow starthistle and can have a long-term benefit on native broadleaf diversity and richness.


2002 ◽  
Vol 80 (2) ◽  
pp. 120-130 ◽  
Author(s):  
Rhoda L Burrows ◽  
Francis L Pfleger

The effect of plant diversity (1, 2, 8, or 16 species) on arbuscular mycorrhizal fungi (AMF) was assessed at the Cedar Creek Long-Term Ecological Research site at East Bethel, Minnesota, from 1997 to 1999. At each of the five samplings, AMF in 16-species plots produced from 30 to 150% more spores and from 40 to 70% greater spore volumes than AMF in one-species plots. Regressions of spore numbers and volumes with percent plant cover, plant diversity, and soil NO3 as independent variables suggest that midsummer plot soil NO3 was the best single predictor of AMF spore production in these plots. Plant diversity influenced spore volume in four samplings and spore numbers in the first three samplings. Plant cover was predictive of spore volume throughout the experiment but of spore number only in the first year. Sporulation by larger-spored AMF species (Gigaspora spp. and Scutellospora spp.) increased significantly with increasing plant diversity, while sporulation of the smaller-spored species varied in response to host diversity. Spore numbers of several AMF species were consistently negatively correlated and none positively correlated with midseason soil NO3 concentrations, demonstrating the adaptation of these AMF species to nitrogen-limited conditions.Key words: mycorrhiza, community, grassland, sporulation, nitrogen, specificity.


Author(s):  
Lyudmila Shumilovskikh ◽  
Pavel Sannikov ◽  
Elena Efimik ◽  
Igor Shestakov ◽  
Vitaliy V. Mingalev

AbstractThe Kungur forest-steppe is the northernmost outpost of European forest-steppe, located in the western pre-Urals within the boreal climatic zone. The co-existence of boreal, nemoral and steppe species with relicts and endemics results in a high plant diversity, making it an important biodiversity hotspot. Under current climate change and strong agricultural impacts, the Kungur forest-steppe is rapidly degrading. In order to develop sustainable management strategies, we studied the vegetation history over the last 3500 years in the natural reserve area Spasskaya Gora. Palynological data indicate that the territory of Spasskaya Gora was largely covered by hemiboreal forests with high proportion of elm during the late Holocene. An opening of the vegetation strongly correlates with erosion, both indicating anthropogenic activities such as lumbering, agriculture, grazing and hay making. The modern Pinus and Betula dominated forests combined with large areas dominated by grasses and herbs appear in the last 300 years and caused by human activity. The data support the ‘anthropogenic’ hypothesis of the Kungur forest-steppe development, suggesting that Pleistocene steppe was replaced by hemiboreal forests during the Holocene. Steppe elements survived on exposed rocks. The recent forest-steppe landscapes dominated by pioneer birch and poplar were formed due to anthropogenic deforestation. With respect to nature conservation, our data demonstrate that prohibition of any anthropogenic activities at Spasskaya Gora will lead to loss of diversity of steppe assemblages over the mid-term. We emphasize that conservation of the high plant diversity of the Kungur forest-steppe must include disturbance factors in the form of selective lumbering, prescribed burning, moderate grazing or traditional mowing.


Author(s):  
Donald J Brown ◽  
Lacy E. Rucker ◽  
Catherine Johnson ◽  
Shane Jones ◽  
Thomas K. Pauley

The Central Appalachian Spruce Restoration Initiative was formed to promote restoration of red spruce Picea rubens forests in Central Appalachia. One goal of the initiative is to increase availability and enhance quality of habitat for wildlife, including the threatened Cheat Mountain salamander Plethodon nettingi. The purpose of this research was to compare microhabitat characteristics between an occupied Cheat Mountain salamander site and early-stage spruce restoration sites, and between four occupied sites and proximal non-detection sites. We found that soil pH was higher and soil moisture was lower at spruce restoration sites compared to the occupied site, and that light intensity, sub-canopy air temperature, and ground-level air temperature were higher in spruce restoration prescriptions with reduced canopy cover. We found that soil moisture was higher at occupied sites compared to proximal non-detection sites, but soil pH was not significantly different. Our study suggests that Cheat Mountain salamanders are associated with low soil pH and high soil moisture, and thus spruce restoration could enhance habitat quality for this species in the long-term.


2018 ◽  
Vol 97 (3) ◽  
pp. 24-28
Author(s):  
M.R. Tumanyan ◽  
◽  
A.A. Svobodov ◽  
E.G. Levchenko ◽  
A.G. Anderson ◽  
...  

2019 ◽  
Vol 24 (4) ◽  
pp. 415-422 ◽  
Author(s):  
Bianca K. den Ottelander ◽  
Robbin de Goederen ◽  
Marie-Lise C. van Veelen ◽  
Stephanie D. C. van de Beeten ◽  
Maarten H. Lequin ◽  
...  

OBJECTIVEThe authors evaluated the long-term outcome of their treatment protocol for Muenke syndrome, which includes a single craniofacial procedure.METHODSThis was a prospective observational cohort study of Muenke syndrome patients who underwent surgery for craniosynostosis within the first year of life. Symptoms and determinants of intracranial hypertension were evaluated by longitudinal monitoring of the presence of papilledema (fundoscopy), obstructive sleep apnea (OSA; with polysomnography), cerebellar tonsillar herniation (MRI studies), ventricular size (MRI and CT studies), and skull growth (occipital frontal head circumference [OFC]). Other evaluated factors included hearing, speech, and ophthalmological outcomes.RESULTSThe study included 38 patients; 36 patients underwent fronto-supraorbital advancement. The median age at last follow-up was 13.2 years (range 1.3–24.4 years). Three patients had papilledema, which was related to ophthalmological disorders in 2 patients. Three patients had mild OSA. Three patients had a Chiari I malformation, and tonsillar descent < 5 mm was present in 6 patients. Tonsillar position was unrelated to papilledema, ventricular size, or restricted skull growth. Ten patients had ventriculomegaly, and the OFC growth curve deflected in 3 patients. Twenty-two patients had hearing loss. Refraction anomalies were diagnosed in 14/15 patients measured at ≥ 8 years of age.CONCLUSIONSPatients with Muenke syndrome treated with a single fronto-supraorbital advancement in their first year of life rarely develop signs of intracranial hypertension, in accordance with the very low prevalence of its causative factors (OSA, hydrocephalus, and restricted skull growth). This illustrates that there is no need for a routine second craniofacial procedure. Patient follow-up should focus on visual assessment and speech and hearing outcomes.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Chinweike Eseonu ◽  
Martin A Cortes

There is a culture of disengagement from social consideration in engineering disciplines. This means that first year engineering students, who arrive planning to change the world through engineering, lose this passion as they progress through the engineering curriculum. The community driven technology innovation and investment program described in this paper is an attempt to reverse this trend by fusing community engagement with the normal engineering design process. This approach differs from existing project or trip based approaches – outreach – because the focus is on local communities with which the university team forms a long-term partnership through weekly in-person meetings and community driven problem statements – engagement.


Author(s):  
Kristin Hartshorn ◽  
Carolyn Rovee-Collier ◽  
Peter Gerhardstein ◽  
Ramesh S. Bhatt ◽  
Teresa L. Wondoloski ◽  
...  

2021 ◽  
pp. 1-11
Author(s):  
Stefanie Bruschke ◽  
Uwe Baumann ◽  
Timo Stöver

Background: The cochlear implant (CI) is a standard procedure for the treatment of patients with severe to profound hearing loss. In the past, a standard healing period of 3–6 weeks occurred after CI surgery before the sound processor was initially activated. Advancements of surgical techniques and instruments allow an earlier initial activation of the processor within 14 days after surgery. Objective: Evaluation of the early CI device activation after CI surgery within 14 days, comparison to the first activation after 4–6 weeks, and assessment of the feasibility and safety of the early fitting over a 12 month observation period were the objectives of this study. Method: In a prospective study, 127 patients scheduled for CI surgery were divided into early fitting group (EF, n = 67) and control group (CG, n = 60). Individual questionnaires were used to evaluate medical and technical outcomes of the EF. Medical side effects, speech recognition, and follow-up effort were compared with the CG within the first year after CI surgery. Results: The early fitting was feasible in 97% of the EF patients. In the EF, the processor was activated 25 days earlier than in the CG. No major complications were observed in either group. At the follow-up appointments, side effects such as pain and balance problems occurred with comparable frequency in both groups. At initial fitting, the EF showed a significantly higher incidence of medical minor complications (p < 0.05). When developing speech recognition within the first year of CI use, no difference was observed. Furthermore, the follow-up effort within the first year after CI surgery was comparable in both groups. Conclusions: Early fitting of the sound processor is a feasible and safe procedure with comparable follow-up effort. Although more early minor complications were observed in the EF, there were no long-term wound healing problems caused by the early fitting. Regular inspection of the magnet strength is recommended as part of the CI follow-up since postoperative wound swelling must be expected. The early fitting procedure enabled a clear reduction in the waiting time between CI surgery and initial sound processor activation.


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