Anatomía de la madera de ocho especies de angiospermas de clima templado

Wood anatomy of Alnus acuminata Kunth, Ostrya virginiana Rose, Quercus dyseophylla Benth. and Quercus glabrescens Benth., Arbutus glandulosa DC., Arbutus tessellata Sorensen, Styrax argenteus Presl. and Buddleia wrightii Robinson, collected in the state of Jalisco and Puebla are given. For each studied taxa, distinctive anatomical features are rebounded, and for each microscopic characteristic, photographs are given. Recommendations on their uses are suggested.

Análisis florístico de un bosque de Abies y el bosque mesófilo de montaña adyacente en Juanacatlán, Mascota, Jalisco, México

<p>Se presenta el análisis florístico de un bosque de Abies y del bosque mesófilo de montaña adyacente, localizados al occidente de Jalisco, México. Se obtuvo una lista de plantas vasculares constituida por 80 familias, 195 géneros y 290 especies, con un índice de diversidad florística de 210.33 especies/km², el cual es elevado al compararlo con el obtenido en otras áreas boscosas similares. Las familias más diversas por cantidad de especies son Asteraceae (46), Fabaceae (22) y Orchidaceae (18). La flora de la comunidad estudiada es similar a lo descrito para los bosques de oyamel en Nueva Galicia y a los bosques mesófilos de la Faja Volcánica Transmexicana. Cinco especies recolectadas en el área se encuentran bajo alguna categoría de riesgo dentro de la Norma Oficial Mexicana NOM-059-SEMARNAT-2010 (<em>Abies flinckii</em>, <em>Comarostaphylis discolor</em> subsp. <em>discolor</em>, <em>Juglans major</em> var. <em>glabrata</em>, <em>Ostrya virginiana</em> y <em>Tilia americana</em> var. <em>mexicana</em>). Los rodales de <em>Abies flinckii</em> son propuestos como área de conservación dado su carácter relictual.</p>

Physiological constraints on response by Ostrya virginiana (Betulaceae) to localized folivory

Individual twigs of eastern hophornbeam were experimentally defoliated at the time of spring peak herbivore abundance for this plant species. When all three leaves directly subtending developing fruits and all leaves (three to five total) from the nearest twig were removed to simulate natural folivory, there was a 25% decrease in mass of individual fruits (but not in fruit number) compared with control twigs. Lower damage of up to 50% area removal for subtending and nonsubtending leaves combined produced no significant decrease in reproductive output. Experimental defoliation had no effect on growth, reproduction, or survivorship of treatment twigs in the subsequent year. At no time during the study was natural herbivore damage high enough on individual twigs to decrease their reproductive output. These results add to the evidence that resource movement among adjacent twigs and branches of woody plants is not sufficient to compensate for localized damage. Thus, we must consider both the pattern of folivory as well as total leaf area removed to understand the effects of folivorous insects on plant growth and reproduction. Key words: folivory, Ostrya virginiana, physiological integration, plant reproduction.

Soil Spot Herbicides for Single-Stem Hardwood Control

Soil spot treatments of undiluted Velpar® L and a concentrated mixture of Spike® 80W were applied around test trees of five hardwood species. The test rates were 2, 4, and 6 ml of herbicide/in. of dbh applied to the soil within 3 ft of each tree Hardwood topkill was assessed after two growing seasons. The 4-ml rate of Velpar L was required to achieve 80% or greater average topkill of sweetgum (Liquidambar styraciflua) and water oak (Quercus nigra) on loamy soils, while a 6-ml rate was needed to exceed 80% topkill of dogwood (Cornus florida). Spike 80W gave about 80% topkill of both water oak and dogwood at the 2-ml rate but was ineffective on sweetgum. Only Spike 80W at the 6-ml rate yielded greater than 70% average topkill of boxelder (Acer negundo) and hophornbeam (Ostrya virginiana). Nearby hardwoods of susceptible species within 3 ft of treated trees were also killed, extending the cost-effectiveness of these hardwood control treatments. South. J. Appl. For. 12(3):199-203.