Rescue and vegetative propagation of Eremanthus erythropappus (DC.) MacLeish in natural stand

The native stands of ‘candeia’ (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study’s objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of ‘candeia’ in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of ‘candeia’, with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Respuesta de material genético de Paulownia spp a tratamiento silvicultural, como estrategia para evaluar su adaptabilidad a condiciones climáticas de estepa espinosa Montano Bajo, Ecuador/Response of Paulownia spp genetic material to silviculture, as a s

El propósito de la investigación consistió en estudiar la respuesta de Paulownia elongata, P. fortunei y un híbrido (Paulownia fortunei x elongata) a un sistema de recepa y evaluar el desempeño de los brotes juveniles, como estrategia para confirmar su adaptabilidad a las condiciones bioclimáticas de estepa espinosa Montano Bajo. El ensayo se instaló en diciembre del 2 015, en una plantación clonal de dos años de edad, plantada por INIAP y ESPOCH en la granja Tunshi, Ecuador. Se establecieron 9 bloques por especie para un total de 27 parcelas experimentales, con 9 observaciones por parcela neta. El tratamiento silvicultural ejecutado fue poda de renovación/recepa, realizando un corte del tallo en bisel a dos centímetros de altura desde el suelo. Las variables evaluadas fueron: Días a la brotación, número de brotes por tocón, diámetro a la base del brote y altura del brote. Los tres materiales estudiados respondieron positivamente a la práctica silvicultural, 90% de tocones brotados a los 61 días de haber realizado el ensayo. A los 29 días de la recepa ya se encontraron brotes epicórmicos en las tres especies de Paulownia, presentando entre 1 y 13 brotes por tocón. En crecimiento dasométrico, P. fortunei experimentó el mayor promedio en altura (81,85 cm), seguida por P. elongata (70,51 cm) y Paulownia hibrido (65,53 cm), siendo 3,5 veces mayor a los promedios de altura y 4 veces mayor en diámetro a la altura de la base del tallo, de los reportados en el primer año de evaluación. Estos resultados avizoran probables comportamientos adecuados y adaptación como una especie forestal-agroforestal de interés para características similares del sitio de estudio. This study is aimed to evaluate the response Paulownia elongata, P. fortunei and hibrid (Paulownia fortunei x elongata) to renewal pruning system and evaluate to develop the juvenile sprout of plants as a strategy to assess its adaptability to the bioclimatic conditions of thorny steppe Montano Bajo, Ecuador. The essay was install in December, 2 015 in one clonal plantation two years old, establish by INIAP and ESPOCH in Tunshi farm, Ecuador. This was established in nine blocks per species for a total of 27 experimental plots with nine observations per net plot. The selviculture treatment executed was renewal pruning, making a bevel cut stem two feet high from the ground. The variables evaluated were: Days sprouting, number of sprouts per stump diameter at the base of the outbreak and height of the outbreak. The three materials studied responded positively to silvicultural practice and 90% of erupted stumps at 61 days responded to development essay. At 29 days from the development the recepa presented epicormics sprout in the three Paulownia species; P. fortunei experienced the greatest average height (81,85 cm), followed by P. elongata (70,51 cm) and hybrid Paulownia (65,53 cm), being 3,5 times greater than the average height and 4 times greater in diameter at the base than those reported in the first year evaluation, these results foresee probable behaviors adapted and adequate as a forestry-agroforestry species of interest from the site of study. Palabras clave: recepa, poda, silvicultura, dendroenergía. Keywords: recepa, pruning, silviculture, wood energy.

Damage caused by cattle to Eucalyptus benthamii trees in pruned and unpruned silvopastoral systems

The objective of this work was to evaluate the effect of tree pruning on the incidence and intensity of the damages caused by cattle to 26-month-old Eucalyptus benthamii, in a silvopastoral system, in the municipality of Pinhais, in the state Paraná, Brazil. The experiment was performed in a randomized complete block design, with two treatments - livestock and forest with pruned eucalyptus (WP), and livestock and forest with unpruned eucalyptus (UP) - and three replicates, characterizing six types of damages and five damage intensities. There were significant differences between the WP and UP treatments for the different types of damages. Cattle entry in the silvopastoral system at 26 months after the planting of eucalyptus causes low-intensity damages to the trees, in the treatment with pruning, and medium-intensity damages to the trees in the treatment without pruning. Damages of stronger intensities were detected in the UP treatment, in which class-two damages (d2 = average damage) were verified in approximately 91% of the trees. The silvicultural practice of pruning E. benthamii trees does not affect the diameter at breast height or the total height of trees. Pruning can be recommended, as it does not affect tree development; moreover, this practice enables the production of knot-free, better-quality wood.

The Impact of Prescribed Burning on Native Bee Communities (Hymenoptera: Apoidea: Anthophila) in Longleaf Pine Savannas in the North Carolina Sandhills

Prescribed burning is a common silvicultural practice used in the management of longleaf pine (Pinus palustris Mill., Pinales: Pinaceae) savannas to reduce hardwood encroachment and ground cover and to maintain biodiversity. We investigated the response of the native bee community (Hymenoptera: Apoidea: Anthophila) in the Sandhills of North Carolina to prescribed burning on a 3-yr rotation over two consecutive years (2012 and 2013). We deployed bee bowl traps in sites that had been burned the year of sampling, 1 yr before, 2 yr before, and in unburned controls. In total, 2,276 bees of 109 species were captured. Bee abundance declined with time since fire, with 2.3 times more bees captured in the most recently burned sites than in unburned controls. Bee diversity also declined with time since fire, with 2.1 times more species captured in the most recently burned sites than in controls. Bee community composition also responded to fire; we present evidence that this response was mediated in part by the effect of fire on the amount of bare ground and canopy cover. Bees nesting aboveground were unaffected by fire, contrary to our expectation that fire would destroy the wood and stems in which these species nest. Our results indicate that prescribed burning is a silvicultural practice consistent with pollinator conservation in longleaf pine ecosystems of the North Carolina sandhills.

The influence of stand density on the structure of harvestmen communities (Opiliones) in a submountain beech forest

Modification of forest stand density by thinning is a common silvicultural practice implemented in management of production forests. However, changes in the stand density can entail considerable changes to the present forest environment and communities. The current knowledge about the effect of stand density modification on the local animal communities is based mainly on the flagship groups such as carabid beetles or birds. We focused our study on harvestmen. We explored how the stand density influences species composition of this species communities in submountain beech forests. The study was conducted in the Kováčovská dolina valley (Kremnické vrchy Mts, Central Slovakia) in 1997 and 1998, the method used was pitfall trapping. In total, 9 harvestmen species from 5 families were recorded. Prior to our research, the forest stands at the study locality were subject to thinning interventions the intensity of which influenced the structure of the local harvestmen communities. The most pronounced was the effect of very intensive thinning with stand density reduced below 0.5. From the recorded species, four preferred forest stands with lower stand density (Lophopilio palpinalis, Oligolophus tridens, Nemastoma lugubre, Trogulus nepaeformis), two species (Platybunus bucephalus, Dicranolasma scabrum) preferred forest stands with higher stand density. Generalization of the observed pattern requires to explore a wider spectrum of beech forests.

MECHANICAL STABILITY OF THE Cabralea canjerana SAPLINGS SUBMITED TO LIBERATION IN SECONDARY FOREST, RS, BRAZIL

ABSTRACT The liberation of trees of interest by cutting competing trees, woody vines and other lianas is a very important silvicultural practice in the management of forest species of interest present in secondary forests. Thus, we aimed to know the influence of the liberation on the mechanical stability and what dimensional height limit of C. canjerana (Vell.) Mart. saplings must have so that there is no problem of buckling of the stem after the liberation. To this end, the liberation of 105 plants of the species was carried out and the diameter and height were measured before and annually for three years after the application of the treatment. Based on the Mechanical Design Theory, a regression model was generated to know to allocation mode of the diameter and height in the analized plants. The minimum diameter for buckling and the safety factor for all trees were calculated. The liberation resulted in the buckling of the stem of five trees, all below the safety limit, that is, with a real diameter smaller than the minimum diameter to support the weight of its height. According to the regression model generated the species grows proportionally in diameter and height. However, the liberation influenced the mechanical stability of the plants liberated, making a greater increment in diameter necessary so that the trees remained standing. The results demonstrate that the dimensions of the trees to be liberated should be considered in order to avoid problems of buckling of the stem after the treatment.

Seasonal dynamics of arginine ammonification in forest soils of Norway spruce pure stands under different silvicultural practices

Effects of seasonal dynamics and silvicultural practice on ammonification of arginine, one of the proteinogenic amino acids, were assessed in surface organic H-horizon of three Norway spruce pure stands in medium altitudes (600 - 660 m a.s.l.). Contents of ammonium ions NH4+measured monthly in the field and contents of NH4+after laboratory incubation of these samples with arginine were taken as dependent variables in ANOVA and in linear regression model using generalised linear model. The aim of the analyses was to determine the significance of decomposition of this amino acid in H-horizon of forest soils and to determine categorical and continuous predictors which influence intensity of the ammonification. Laboratory experiments confirmed its close link to seasonal dynamics, as well as to forest management; however the last mentioned was firstly found as less significant when compared within whole season. As regards to seasonal dynamics in forest soils, the highest amount of ammonium ion was released in May and the lowest in July. As regards to the silvicultural practice applied, more ammonium ion was released under mature spruce monoculture, especially in August and May; in the young stands, the method of thinning had no effect on the ammonium ion release. However, the arginine ammonification was found to be influenced by ammonium nitrogen content (slight, less significant negative correlation) and by soil water content (stronger positive significance), especially in the stand with thinning from below. This was concluded to be caused by changes in stand microclimate in function of the silvicultural practice.

Thinning Southern Pines - A Key to Greater Returns

Thinning is an important silvicultural practice that redistributes the growth potential of the site to the best trees. Diameter growth rates are maintained or increased on residual trees after thinning, which increases the return on investment from higher-value trees. Biologically, thinning accelerates stand development by favoring the tallest, best-formed trees over those that are diseased, overtopped, crooked, forked, or otherwise undesirable and likely to die on their own if left in the stand long enough. In addition, thinning provides periodic income, improves access for equipment, recreation and hunting, and creates a generally healthier stand. Thinning is also beneficial for wildlife, especially when combined with prescribed fire or herbicide use to control competing vegetation. By allowing more light to reach the forest floor, thinning promotes growth of plants important as food and/or cover for wildlife species. Landowners are encouraged to consult with or hire a professional forester to assist with thinning and other forest management activities. This 6-page fact sheet was written by Chris Demers, Michael Andreu, Babe McGowan, Alan Long, and Jarek Nowak, and published by the UF Department of School of Forest Resources and Conservation, July 2013. http://edis.ifas.ufl.edu/fr159