Pine sawdust biochar as a potential amendment for establishing trees in Appalachian mine spoils

Early growth and survival of tree seedlings is often poor on reclaimed coal surface mines in Appalachia. Biochar produced in bioenergy generation has potential for use as an amendment to improve seedling performance. Mine soil was collected from a recently reclaimed coal surface mine in Wise County, Virginia and mixed with loblolly pine (Pinus taeda L.) sawdust biochar, simulating application rates of 2.3, 11.2 and 22.5 Mg ha-1. Unplanted leaching columns and 4 L tree planting pots were filled with these biochar-soil mixtures, plus controls of pure mine soil and pure biochar. For the tree planting pots, additional pots were created where the biochar was applied as a topdressing at the same application rates as in the mixtures. One-year-old seedlings of both American sycamore (Platanus occidentalis L.) and black locust (Robinia pseudoacacia L.) were planted. Unplanted leaching columns were leached with collected rainwater for six months to simulate weathering. Trees were grown for one growing season. Black locust had higher average above-ground dry woody biomass (24.4 g) than American sycamore (17.0 g), and also higher below-ground biomass (61.0 g compared to 30.2 g). The pure biochar produced greater average below-ground biomass (99.9 g) than the pure mine soil (46.9 g). All of the biochar treatments produced greater average above-ground woody biomass (19.1 g – 33.4 g) than the pure mine soil (10.9 g). After weathering, biochar provided less available soil phosphorus, calcium and iron than the mine soil itself while increasing soil carbon and organic matter. High (22.5 Mg ha-1) biochar applications increased soil volumetric water holding capacity to 18.6% compared to 13.4% for pure mine soil. Naturally-occurring herbaceous biomass in the pots was negatively correlated with above-ground woody biomass at r = -0.483. Topdressing and full incorporation of biochar were not significantly different in their effects on biomass. Results suggest that pine biochar either broadcast at 2.3 - 22.5 Mg ha‑1, or mixed in planting holes with backfill soil, will promote faster above-ground growth and larger root systems in seedlings in mine soils. Further studies should test these methods in the field over multiple years and further refine recommendations of the rate of biochar to use and how best to apply it. New systems are being developed in Appalachia to produce biofuels and biochar from local biomass and to recycle biochar into the land base to enhance future biomass productivity. Applying 4 L of biochar mixed with the backfill of newly-planted trees is the top recommended practice for tree performance

Excavating roots with explosives

"An important limitation In the study of tree roots has traditionally been the time necessary to excavate roots without injuring their fine structure. Thus, many root studies have been based on small samples and consequently contain large errors of estimation. This Note describes how large numbers of root systems from sapling-sized trees can be excavated rapidly and with minimum injury by placing patterned charges of high explosive in the soil."--P. [1]

EFFECTS OF PRESCRIBED BURNING, MECHANICAL, AND CHEMICAL TREATMENTS TO CURTAIL RHODODENDRON DOMINANCE AND REDUCE URBAN INTERFACE FUEL LOADS

One-half-acre treatment areas were delineated within prescribed burns. Cutting treatments consisted of chainsaw or brushsaw severing of all rhododendron stems within 6 in of the ground surface. Herbicide and herbicide followed by fire treatments consisted of basal applications of triclopyr or imazapyr in methylated seed oil on each plot. Cutting and burning treatments followed by herbicides utilized foliar applications of triclopyr or imazapyr in emulsions to all resprouting rhododendron. All herbicide plots were randomly split in half for the application of imazapyr or triclopyr on different halves. Analyses of variance and mean separation by LSD were used to compare treatment effectiveness for fuel loading and costs

Five-year effects of cutting and herbicide treatments on control of Rhododendron flavum Don., and macronutrient pools in eastern beech (Fagus orientalis Lipsky) forests of Turkey

Esen, Derya/0000-0003-4175-758XWOS: 000280650100005This experiment was carried out in a mature (> 100-year-old) eastern beech forest in the Eastern Black Sea Region (BSR) of Turkey. The effects of experimental practices to control the woody plant Rhododendron flavum Don., including grubbing, manual cutting, and foliar and cut-stump spraying with imazapyr and triclopyr, were assessed on understory and forest floor biomass and nutrients, as well as soil bulk density and nutrient content. The cut plots had 5, 15, and 38 times greater competing vegetation biomass than did the plots treated with triclopyr, grubbing, and imazapyr, respectively. Because of the increased biomass, the amount of understory N, P, Ca, K, S, and Mg content on the cut plots was also substantially higher when compared to the grubbed, imazapyr-treated, and triclopyr-treated plots. Triclopyr and imazapyr applications brought about two- and threefold greater dead organic matter on the forest floor than did cutting and grubbing, respectively. As a result, forest floor macronutrient contents on the imazapyr- and triclopyr-treated plots were significantly greater than on the cut plots. Five years after treatments, soil bulk density at the 10-20 cm depth on the imazapyr-sprayed plots was about 14% higher than that on other treatments. Herbicides, especially imazapyr and grubbing were effective in controlling rhododendron. Macronutrients stored in the rhododendron were released to the forest floor after vegetation was controlled with herbicides

Site characteristics of Leitneria floridana (Leitneriaceae) as related to potential biological control of the invasive tree-of-heaven, Ailanthus altissima

Volume: 2011-27Start Page: 1End Page: 1

Failure mode and prediction of the strength of branch attachments

Predicting the strength of branch attachments is important for arborists and urban foresters because branch failure can cause damage and injuries. Previous studies have shown that the ratio of branch to trunk diameter is a better predictor of strength than the angle of attachment. Aside from these two factors, however, few other morphological measures of the attachment have been investigated with respect to predicting the strength of attachments. Many branch attachments from three species were broken on a testing machine and breaking stress was calculated. Prior to breaking, various morphological measures and ratios describing the attachment were made. Breaking stress varied by form of the attachment (u-shaped or v-shaped), failure mode, and the presence of included bark. The best predictor of breaking stress was the ratio of branch to trunk diameters. Results are discussed in the context of previous studies and with respect to tree risk assessment