Environmental Microbiology: Tannins & Microbial Decomposition of Leaves on the Forest Floor

2010 ◽  
Vol 72 (8) ◽  
pp. 506-512 ◽  
Author(s):  
M. Brian Traw ◽  
Nancy Gift
Keyword(s):  
Scientific Inquiry ◽  
Forest Floor ◽  
Bacterial Culture ◽  
White Oak ◽  
Decomposition Rates ◽  
Microbial Decomposition ◽  
Simple Question ◽  
Leaf Tissues ◽  
Student Inquiry ◽  
Tulip Poplar

Tannins are plant chemicals that humans find useful in products as diverse as tea and leather. Why do plants produce these compounds? One possible answer is defense against pathogens and herbivores. In this series of laboratory exercises, student inquiry begins with a simple question: What happens to the multitude of leaves that drop each autumn? This inquiry brings students from the outdoors to the laboratory, where they observe differences in leaf decomposition rates and the natural abundance of bacteria and tannin concentrations in leaf tissues of red oak, white oak, and tulip poplar. In the process, students increase their understanding of plant chemistry, bacterial culture, graphing, and natural history, while experiencing the iterative nature of scientific inquiry.

Confronting Scientific Misconceptions by Fostering a Classroom of Scientists in the Introductory Biology Lab

2014 ◽  
Vol 76 (8) ◽  
pp. 518-523
Author(s):  
Matthew L. Holding ◽  
Robert D. Denton ◽  
Amy E. Kulesza ◽  
Judith S. Ridgway
Keyword(s):  
Scientific Inquiry ◽  
Scientific Community ◽  
Introductory Biology ◽  
Fundamental Component ◽  
Hands On ◽  
Education Levels ◽  
Recent Trends ◽  
Science Curricula ◽  
Biology Lab ◽  
Student Inquiry

A fundamental component of science curricula is the understanding of scientific inquiry. Although recent trends favor using student inquiry to learn concepts through hands-on activities, it is often unclear to students where the line is drawn between the content and the process of science. This activity explicitly introduces students to the processes of science and allows the classroom to become a scientific community where independent studies are performed, shared, and revised. We designed this activity to be relatively independent of the chosen content, allowing instructors to utilize the presented framework for classes of various disciplines and education levels.

scholarly journals Abnormal Leaf Development on White Oaks Linked to Drift of Chloroacetamide Herbicides

2005 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Jayesh B. Samtani ◽  
John B. Masiunas ◽  
James E. Appleby
Keyword(s):  
Central Region ◽  
Leaf Development ◽  
North Central Region ◽  
White Oak ◽  
North Central ◽  
The North ◽  
Leaf Tissues ◽  
Herbicide Drift ◽  
Possible Cause ◽  
Insect Attack

In the last few decades, white oak in the north central region have developed malformed spring leaves called “leaf tatters.” Symptoms begin with the death of interveinal leaf tissues, eventually leaving only the main leaf veins with little interveinal tissues present. Winter injury, frost, insect attack, and herbicide drift were all thought to be possible causes of leaf tatters. This study indicates that drift of chloroacetamide herbicides from applications onto corn and soybean fields is a possible cause of the leaf tatters syndrome. Accepted for publication 14 February 2005. Published 21 February 2005.

High temporal resolution measurements of CO2, CH4 and N2O in a Norwegian mire ecosystem using automated light-dark chambers

2020 ◽  
Author(s):  
Linsey Avila ◽  
Klaus Steenberg Larsen ◽  
Andreas Ibrom ◽  
Norbert Pirk ◽  
Poul Larsen
Keyword(s):  
Water Table ◽  
Natural Water ◽  
Water Levels ◽  
Organic Soils ◽  
High Temporal Resolution ◽  
Decomposition Rates ◽  
Microbial Decomposition ◽  
Enhanced Production ◽  
Nature Restoration ◽  
Ch4 And N2o

<p>Regeneration of natural hydrology in previously drained peatlands is becoming a widespread practice in nature restoration projects around the world. The drained peatlands are well known for their high emissions of CO<sub>2</sub> caused by increased microbial decomposition rates in these very organic soils when suddenly exposed to higher levels of oxygen availability. Restoring natural water levels reduces again the decomposition rates and CO<sub>2</sub> emissions. It remains uncertain, however, how rates of the much stronger greenhouse gases, CH<sub>4</sub> and N<sub>2</sub>O, respond to the restored water table and these fluxes can potentially offset the GHG balance of rewetting peatlands.</p><p> </p><p>In a new project in Norway (close to Trysil, Innlandet), we installed five ECO<sub>2</sub>flux automated chambers and one eddy flux tower in each of two areas of drained peatlands.  The automatic chambers were placed with different distances to the ditches reflecting variation in water table with greatest water level variability at the edges of the ditches. After two years, the ditches will be filled and the natural water table will be regenerated in one of the areas in order to follow the differences in the fluxes of CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O upon rewetting.</p><p> </p><p>We here present an analysis of the first year’s data from the ECO<sub>2</sub>flux chambers including the total greenhouse gas budget for the period measured. The fluxes of CO<sub>2</sub> showed only little spatial heterogeneity whereas we observed a significant spatial pattern of higher fluxes of CH<sub>4</sub> in plots where the water table was closer to the surface. The driest plots, i.e. the edges of the drain ditches, showed also the lowest emissions of CH<sub>4</sub>. The trend was similar in the two areas. This is an indicating that planned rewetting after two years of the project may lead to enhanced production and emission of CH<sub>4</sub> in the area. So far, we observed no N<sub>2</sub>O emissions above the detection limit of the system indicating that CO<sub>2</sub> and CH<sub>4</sub> are the major components of the GHG budget.</p>

scholarly journals White Oak and Northern Red Oak Leaf Injury from Exposure to Chloroacetanilide Herbicides

HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Jayesh B. Samtani ◽  
John B. Masiunas ◽  
James E. Appleby
Keyword(s):  
Red Oak ◽  
Quercus Alba ◽  
Northern Red Oak ◽  
White Oak ◽  
Leaf Injury ◽  
Leaf Unfolding ◽  
Red Oaks ◽  
Chloroacetanilide Herbicides ◽  
Leaf Tissues ◽  
Tree Injury

Previous research by the authors found simulated acetochlor (with atrazine) and s-metolachlor drift to white oak at the leaf unfolding stage caused loss of interveinal tissues (leaf tatters). Reports of leaf tatters in the landscape and nursery settings are more common on white oak (Quercus alba L.) than on northern red oak (Quercus rubra L.). Our objectives were to determine if white and northern red oak differed in susceptibility to chloroacetanilide herbicides, if injury varied between chloroacetanilide herbicides, and if adding atrazine increased leaf injury. Two-year-old seedlings at the leaf unfolding stage were treated with acetochlor, s-metolachlor, and dimethenamid-P alone or combined with atrazine at 1%, 10%, and 25% of the standard field use rate. Within 6 days, all chloroacetanilides at 10% and 25% field use rates, alone or combined with atrazine, caused leaf tatter injury in both species. Acetochlor, s-metolachlor, and dimethenamid-P caused a similar type of leaf injury. Atrazine did not cause loss of leaf tissues or increase injury from chloroacetanilides. At 1% field use rate, only acetochlor, acetochlor + atrazine, and dimethenamid-P caused leaf injury to northern red oaks. The white oaks were not injured by all of the chloroacetanilide treatments at 1% field use rate. The northern red oaks were slightly more susceptible to chloroacetanilides compared with the white oaks. A second study found acetochlor only injured northern red oak when applied at the leaf unfolding stage and only at 25% of field use rate. Acetochlor at 1% field use rate did not injure red oak. Research is needed to explain the greater frequency of leaf tatters on white oaks than on northern red oaks in the landscape and to develop strategies to avoid tree injury.

scholarly journals Methods to Evaluate Host Tree Suitability to the Asian Longhorned Beetle, Anoplophora glabripennis

2002 ◽  
Vol 20 (3) ◽  
pp. 175-180 ◽  
Author(s):  
Scott W. Ludwig ◽  
Laura Lazarus ◽  
Deborah G. McCullough ◽  
Kelli Hoover ◽  
Silvia Montero ◽  
...  
Keyword(s):  
Sugar Maple ◽  
Larval Survival ◽  
Red Oak ◽  
Anoplophora Glabripennis ◽  
Northern Red Oak ◽  
Green Ash ◽  
Asian Longhorned Beetle ◽  
White Oak ◽  
First Instar ◽  
Tulip Poplar

Abstract Two procedures were evaluated for assessing tree susceptibility to Anoplophora glabripennis. In the first procedure, adult beetles were caged with a section of sugar maple, northern red oak, white oak, honeylocust, eastern cottonwood, sycamore or tulip poplar wood. Results showed that females laid viable eggs on sugar maple, red oak, white oak and honeylocust. Oviposition did not occur on cottonwood, sycamore, or tulip poplar. Eighty-seven percent of the first instar larvae survived in white oak, followed by sugar maple (82%), honeylocust (50%), and red oak (39%). In the second procedure, first instar larvae were manually inserted into potted sugar maple, green ash, and red oak trees and allowed to feed for 60 or 90 days. Significantly more larvae survived for 90 days within the red oak (67%) compared to green ash (17%). Larvae recovered from red oak weighed significantly more than larvae from sugar maple or green ash. Larval survival was positively related to height of insertion. These results indicate: 1) controlled laboratory and greenhouse-based procedures can be used to assess tree suitability to A. glabripennis and 2) A. glabripennis will oviposit and larvae can develop in northern red oak for up to 90 days, suggesting that this species may be a potential host.

scholarly journals Changes in Austrian pine forest floor properties in relation with altitude in mountainous areas

2008 ◽  
Vol 54 (No. 7) ◽  
pp. 306-313 ◽  
Author(s):  
O. Sevgi ◽  
B. Tecimen H
Keyword(s):  
Forest Floor ◽  
Vegetation Period ◽  
High Elevation ◽  
Limiting Factors ◽  
Nutrient Element ◽  
Mountainous Areas ◽  
Decomposition Rates ◽  
Significant Difference ◽  
Tree Canopies ◽  
Medium Correlation

Altitudinal studies has become of interest to ecologists concentrated on functional alterations aiming to clarify the effects of limiting factors. Nutrient element release from forest floor (FF) decomposition is suppressed by those factors such as low temperature, shortened vegetation period concluding FF accumulation at high elevation fields. To draw out a response to the FF decomposition issue, FF layers as leaf + fermentation (L + F) and humus (H) were collected from 37 representative sample plots along an altitudinal gradient (from 1,400 m to 1,710 m) on Kaz (Balikesir-Turkey) mountain. Mass, pH, organic matter (OM) and total nitrogen (Nt) contents of FF were investigated to explain the relation between decomposition and altitudinal effects. The results revealed that total FF mass and (L + F), (H) sub-fraction masses through elevation show an insignificant relation with the altitude. No significant difference was found between the altitudinal groups in the OM content of L + F. Besides there are significant negative correlations between OM contents (%) of L + F and H layers and altitude with the coefficient values 0.342 (<I>P</I>< 0.05) and 0.597 (<I>P</I> < 0.01), respectively. The Nt content of L + F layer also increases through the elevation revealing a medium correlation with altitude (0.368; <I>P</I> < 0.05). The increasing Nt and decreasing OM contents show better decomposition rates at higher sites regardless of the altitude induced climatic changes. We assume that the forest floor accumulation under tree canopies provides a better decomposition relying on the microclimatic environment mediated by tree canopies, in spite of the altitude.

Relationships between cellulose decomposition, Jenny's k, forest-floor nitrogen, and soil temperature in Alaskan taiga forests

1983 ◽  
Vol 13 (5) ◽  
pp. 789-794 ◽  
Author(s):  
John F. Fox ◽  
Keith Van Cleve
Keyword(s):  
Decomposition Rate ◽  
Forest Floor ◽  
Black Spruce ◽  
Nitrogen Concentration ◽  
Major Influence ◽  
Decomposition Rates ◽  
Cellulose Decomposition ◽  
Taiga Forest ◽  
Wide Range ◽  
Cellulose Filter

Forest-floor decomposition is compared among 16 Alaskan taiga forest stands. These include black spruce (Piceamariana (Mill.) B.S.P.), white spruce (Piceaglauca (Moench) Voss), and birch (Betulapapyrifera Marsh.), aspen {Populustremuloides Michx.), and balsam poplar (Populusbalsamifera L.) types, spanning a wide range in decomposition rates, forest-floor microclimates, and litter quality. Jenny's index of decomposition rate, k, is reasonably well correlated with annual cellulose (filter-paper) decomposition differences among stands. Both estimates of decomposition rate are correlated with forest-floor heat sum and forest-floor nitrogen concentration. These between-site correlations support inferences based upon experimental work claiming that temperature and forest-floor chemical quality have a major influence upon the level of decomposition in a particular stand. Inferences about the factors regulating decomposition rate around an average level within one stand cannot legitimately be made from the same correlations. Moisture has not been considered in this analysis, but could also be important to between-stand differences in decomposition rate.

A comparison of the effects of different shelterwood harvest methods on the survival and growth of acorn-origin oak seedlings

2011 ◽  
Vol 41 (12) ◽  
pp. 2359-2374 ◽  
Author(s):  
Patrick H. Brose
Keyword(s):  
Seedling Growth ◽  
Forest Floor ◽  
Seedling Survival ◽  
Quercus Alba ◽  
White Oak ◽  
Quercus Velutina ◽  
Germination Success ◽  
Survival And Growth ◽  
Insight Into ◽  
Oak Seedlings

Timely development of newly germinated oak (Quercus spp.) seedlings into competitive-sized regeneration is an essential part of the oak regeneration process. The amount of sunlight reaching the forest floor partly governs this development, and foresters often use the shelterwood system to expose oak seedlings to varying degrees of insolation. To further understand the seedling development–sunlight–shelterwood relationships, I conducted a multiyear study at five locations in Pennsylvania. Each location had four stands either uncut or recently treated with one of three shelterwood harvest methods (preparatory cut, first removal cut, or final removal cut) resulting in four different levels of sunlight reaching the forest floor. In each stand, four 32 m2 plots were prepared, and each was planted with 400 acorns of black (Quercus velutina Lam.), chestnut (Quercus montana Willd.), northern red (Quercus rubra L.), or white oak (Quercus alba L.) and protected from wildlife. Germination success was universally high and for the next 8 years, I monitored seedling survival and measured seedling growth. The final and first removal cut treatments had higher seedling survival than the preparatory cut and uncut treatments. Oak seedling growth was positively related to sunlight availability; seedlings in the final removal cut grew the most, followed in descending order by those in the first removal cut, preparatory cut, and uncut treatments. These findings provide insight into the subtleties of regenerating oak forests with the shelterwood system.

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