Efectos a corto plazo de una quema prescrita de baja intensidad sobre los invertebrados epiedáficos de un pinar canario

[EN] The effects of prescribed fire on the forest upper ground layer can have consequences for invertebrate communities. In the Canary Islands, prescribed fire is starting to be used as a tool to reduce wildfire risk, but the impacts of this management practice on the Canarian pine forest have not been investigated. The aim of this study is to explore the short-term effects of prescribed burning on the most abundant groups of ground-dwelling invertebrates. Three of six plots were randomly burnt and the other three were used as controls. Pitfall trapping was used to collect the ground-dwelling invertebrates four months after burning. No differences were found in total richness, diversity, evenness and total abundance between treatments. Only Psocopteran abundance increased after fire. Litter depth, total vegetation cover and decayed wood cover were different between treatments. Canonical Correspondence Analyses (CCA) revealed differences in species composition between treatments using these environmental variables. It is concluded that the use of low-intensity prescribed burning in this stand did not have an important impact on the structural parameters of the ground-dwelling invertebrate community, but species composition changed. Care shoud be taken with valuable endemic, rare or sensible species[ES] Los efectos del fuego prescrito sobre la capa superficial del suelo pueden tener consecuencias para las comunidades de invertebrados. Las quemas prescritas se están empezando a aplicar en las Islas Canarias como una herramienta para reducir el riesgo de incendios forestales, pero el impacto ecológico de estas prácticas aún no ha sido estudiado en el pinar canario. El objetivo de este trabajo es explorar los efectos a corto plazo de las quemas prescritas sobre los grupos más abundantes de invertebrados epiedáficos. Se establecieron seis parcelas, de las que tres fueron quemadas al azar y las otras tres se usaron como controles. Los muestreos de invertebrados se realizaron cuatro meses después de la quema mediante trampas de caída. No se encontraron diferencias entre tratamientos en riqueza, diversidad, equitatividad y abundancia total de invertebrados. En cuanto a los grupos, Psocoptera fue el único que incrementó su abundancia tras el fuego. Se encontraron diferencias significativas entre tratamientos en profundidad de mantillo, cobertura total de vegetación y cobertura de madera muerta en descomposición. Dichas variables se incluyeron en un Análisis Canónico de Correspondencia (CCA) revelando diferencias entre tratamientos en composición de especies. Se concluyó que, aunque las quemas prescritas no tienen un impacto notable sobre los parámetros estructurales de la comunidad de invertebrados, sí provocan cambios en la composición de especies, que deben ser valorados en presencia de especies endémicas, raras o sensiblesSIServicio Territorial de Medio Ambiente del Cabildo de Gran Canaria, who granted permission to work in Pinus canariensis forest and to do the prescribed fire and partially supported this study (CI02380503). We also thank Ministerio de Educación y Ciencia (MEC) of the Spanish government, which provided financial support to do this work, granting the first author a FPU (Formación de Profesorado Universitario, AP2005-4736) pre-doctoral fellowshi

Age and season effects on quality of diets selected by Criollo crossbred goats on rangeland

The objectives of this study were to determine the effects of age of goats (4-week old, 6.2 0.7 kg vs mature, 46.9 5.6 kg) and season (rainy vs dry) on nutrient content of diets selected by Criollo crossbred female goats on an overgrazed Chihuahuan desert rangeland. Two groups of goats, 10 goat kids and 10 non-lactating pluriparous goats from a commercial goat herd were used. Diet quality and dry matter (DM) intake was assessed via repeated collections (3-h periods) of forage from the mouth of goats, which were momentarily restrained using a light short permanent rope tightened to their neck while grazing. Feed intake was assessed by 24-h fecal collection with canvas fecal-collection bags. Mature animals ate more (P < 0.01, 23 g DM/kg bodyweight 7 s.d.) than goat kids (19.5 g DM/kg bodyweight 6 s.d.) across grazing seasons, but DM digestibility of selected diet was greater (P < 0.01) in goat kids than in mature goats (58.5 4.0% vs 55.3 3.5%, respectively) across seasons. Ash (100 16 vs 79 13 g/kg DM), phosphorus (1.36 0.41 vs 1.13 0.36% DM) and crude protein (94.5 4 vs 88.5 5 g/kg DM) contents were greater (P < 0.01) in diets selected by goat kids compared with mature goats. Dietary protein was greater in rainy than in the dry season. Across grazing seasons, herbage selected by goat kids had a lower (P < 0.01) concentration of neutral detergent fibre and acid detergent fibre than did that selected by mature goats. There was an age by grazing season interaction (P < 0.05) for most chemical components of forages selected by goats. In conclusion, both age and season affected diet quality of goats on rangeland, as goat kids ingested a diet richer in nutrients than that of mature goats. This supports the theory that herbage selection is shaped by physiological effort and, consequently, nutrient consumption is driven by higher nutrient requirements for growth, although incomplete development of rumen function and small body mass limited feed intake in preweaning goat kids

Prescribed Burning and Clear-Cutting Effects on Understory Vegetation in a Pinus canariensis Stand (Gran Canaria)

[EN] Prescribed fires are a powerful tool for reducing fire hazards by decreasing amounts of fuel. The main objective is to analyze the effects of prescribed burning on the understory vegetation composition as well as on the soil characteristics of a reforested stand of Pinus canariensis. The study attempts to identify the effects of the preburning treatment of cutting understory vegetation on the floristic parameters of the vegetation community. This study was carried out for two years following a prescribed fire in a Canarian pine stand. Cutting and burning treatment affected species composition and increased diversity. Burnt and cut plots were characterized by a diverse array of herbaceous species and by a lower abundance of Teline microphylla (endemic legume), although burning apparently induced its germination. Cut treatment was more consistently differentiated from the control plots than burnt treatment. Soil K decreased after both treatments, pH slightly decreased after cutting, while P and Ca increased after fire. From an ecological point of view, prescribed burning is a better management practice than cutting the woody species of the understory. However, long-term studies would be necessary to evaluate the effects of fire intensity, season and frequency in which the prescribed burning is appliedSIConsejería de Medio Ambiente y Emergencias (Gran Canaria Council), especially UOFF and PRESA, for granting permission to work in Pinus canariensis forest, carrying out the prescribed fire, and partially supporting this study (CI02380503). They also thank the Ministerio de Educación y Ciencia (MEC) of the Spanish Government, which provided financial support by granting C. García a FPU (Formación de Profesorado Universitario, AP2005- 4736) predoctoral fellowshi

Fire response of the endangered Pinus culminicola stands after 18 years in Cerro El Potosí, northeast Mexico

Abstract Aim of the study: To analyze the impact of the 1998 wildfire on dwarf pine (Pinus culminicola) population stands 18 years after the fire. Area of study: Cerro el Potosí, Nuevo León (México). Material and methods: We measured regeneration, biovolume of individuals, diversity and species composition in unburned and burned plots randomly selected in the area. Main results: Recovery was very slow, with limited dense natural regeneration and very slow growth. Significant differences between control and burned plots were found with respect to regeneration, species composition, evenness and soil nutrients, suggesting that fire could promote natural regeneration and biodiversity in these communities. Research highlights: Management efforts are necessary to maintain a natural fire regime and ensure grazing exclusion in order to favor the conservation of the community dominated by this rare species P. culminicola. Additional keywords: fire ecology; DCA; Permanova; richness. Abbreviations used: CIC (Cationic Interchange Complex); DCA (Detrended Correspondence Analysis); EC (Exchangeable Cation); OM (Organic Matter). Authors´ contributions: Conceived, designed and performed the experiments: JRA, EE and HGR. Analyzed the data: JRA, JAV, JRE and YM. Contributed reagents/materials/analysis tools: JAV, JRE, YM, IC and JU. Wrote the paper: JRA, JAE and EE. All authors read and approved the final manuscript. Citation: Arévalo, J. R.; Estrada, E.; Encina, J. A.; Villarreal, J. A.; Escobedo, J. R.; Morales, Y.; Cantú, I.; González-Rodríguez, H.; Uvalle, J. (2017). Fire response of the endangered Pinus culminicola stands after 18 years in Cerro El Potosí, northeast Mexico. Forest Systems, Volume 26, Issue 3, e015. https://doi.org/10.5424/fs/2017263-11566 Received: 20 Apr 2017. Accepted: 21 Nov 2017. Copyright © 2017 INIA. This is an open access article distributed under the terms of the Creative Commons Attribution (CC-by) Spain 3.0 License. Funding: Program of cooperation Universidad de La Laguna-Universidad Autónoma de Nuevo León, included in the official frame agreement of these institutions; Facultad de Ciencias Forestales of the Universidad Autónoma de Nuevo León; University of La Laguna (Research Program) covered the travel expenses of JRA. Competing interests: The authors have declared that no competing interests exist. Correspondence should be addressed to José R. Arévalo: [email protected]

Ingeniería Forestal y ambiental en medios insulares

Las Islas Canarias a pesar de su reducida extensión y del relativo poco peso específico a nivel mundial, no es ajena a los problemas globales detectados en la conservación de bosques y en la importancia que éstos tienen para obtener beneficios económicos, socioculturales y ambientales. La gestión forestal sostenible es en este sentido esencial para asegurar y compatibilizar los diversos beneficios del bosque. El papel específico de los bosques y su gestión son sin embargo temas aún por conocer en nuestras islas, por lo que el Año Internacional de los Bosques ha representado una oportunidad única para dar a conocer el mundo forestal y acercarlo a nuestra sociedad. El presente libro consta de 25 capítulos donde se ha contemplado la mayoría de los aspectos a tener en cuenta en la planificación y gestión del medio forestal y natural. Desde la historia forestal del archipiélago, hasta el uso y técnicas de manejo de los recursos naturales, incluyendo el agua, la energía en forma de biomasa y la selvicultura

Species turnover during secondary succession in a laurel forest stand 60 years after clearcutting

Aim of study: The present study was designed to evaluate the effects of clearcutting and recovery of a laurel forest stand, 50 years after felling.Area of study: Laurel forest stand in Agua García, Tenerife (Canary Islands)Material and methods: Structural stand parameters were measured in a large patch of laurel forest.Main results: The results revealed that Erica arborea and Ilex canariensis have acted as pioneer species in the broad sense of the term, while Morella faya has remained abundant throughout the study. Persea indica became increasingly dominant throughout succession, as indicated by several different structural parameters.Research highlights: Recovery of the laurel forest after clearcutting has been possible in some areas without any further forest management, as indicated by the species composition and forest structure.Key words: Canary Islands; Ecological Restoration; Laurel forest; Succession

Growth and nutrients content of Atriplex canescens across a soil electric conductivity gradient

Atriplex canescens canopy cover, biomass production, and nutrient content were evaluated after four years of livestock grazing exclusion and mechanical shrub removal, except A. canescensin an arid rangeland with a slightly saline soil and with a long history of heavy livestock grazing in the southern Chihuahuan Desert, Mexico (24° N). Twenty 3 × 3 m paddocks were established in terrains with three levels of electric conductivity (EC): 1.6 dS/m. Atriplex canescens canopy cover was higher (49.5%; p1.6 dS/m than paddocks with soil EC <1.4 and 1.4–1.6 dS/m (32.1 and 22.9%, respectively). Above-ground biomass did not differ between paddocks with soils with EC of <1.4 and 1.4–1.6 dS/m (1309 ± 535 and 1372 ± 180 kg DM/ha), but biomass increased 2.7 times (p<0.01) when soil EC was greater than 1.6 dS/m. The soil EC had no effect on the levels of crude protein (range 13.6 to 14.3%), neutral detergent fiber (range 56.5 to 57.7%) and ash (range 14.5 to 16.4%). In vitro dry matter digestibility (IVDMD) of the foliage of A. canescens was not affected by of soil EC level (range 60.4 to 62.2%). It was concluded that in an arid rangeland with slight saline soil, the increase in salinity favors canopy cover and biomass production of A. canescens without altering nutrient content and IVDMD of this fodder shrub