Forest Systems

Early testing for improving growth under water shortage in Eucalyptus globulus Labill.

2024-04-16T14:29:47+02:00

Aim of study: We aimed at identifying differences in the response to water shortage between Eucalyptus globulus clones.

Area of study: Field trials were established in SW Spain.

Material and methods: Potted plants from six clones were grown in a greenhouse for 35 days under two watering regimes. Two clones were F₀ genotypes and the other four were F₁ (hybrid) genotypes, including one inbred clone. Differences in stomatal conductance, hydraulic traits, growth and specific leaf area (SLA) were analyzed.

Main results: Water shortage decreased SLA, growth in height and leaf area and leaf-specific hydraulic conductivity (K_Lmax). We measured the highest growth in F₁ genotypes and the lowest in the clone in which SLA was lowest. The inbred clone showed the highest growth reduction under water shortage. There was substantial hysteresis between leaf water potential (Y) and native embolism, most probably a result of combined cavitation and refilling. High losses of hydraulic conductance were compatible with high stomatal conductances. Maximum values of stomatal conductance decreased with the soil water content estimated from predawn Y and were lowest in the inbred clone, showing less plasticity and a diminished ability to cope with high temperatures, which could explain its poor development under field conditions.

Research highlights: Soil water content and predawn Y appeared as critical factors controlling stomata closure, while stomatal conductance and SLA could be useful to predict differences in growth and survival from early trials.

How deforestation and forest use affect tree diversity in a conifer forest from central Mexico

2024-04-16T14:36:51+02:00

Aim of study: To assess the association of deforestation and forest use with tree diversity and dominance of pine species.

Area of study: La Malinche National Park, central Mexico.

Material and methods: Three forest stands were selected on each of four slopes in La Malinche National Park, in which the percent forest cover was determined using a concave spherical densitometer. Additionally, we estimated logging, firewood, and ocoteo as indirect measures of forest use. In each forest stand, we set five 0.1-ha circular plots and we recorded tree species, diameter at breast height, and height of all individuals ≥1.5 m. We estimated diversity using Hill numbers (^qD). We identified dominant species from rank-abundance curves, and explored the dissimilarity between forest stands for the three q orders. Using generalized linear mixed-effects models, we evaluated the relationships of deforestation and forest use with species diversity and pine dominance, and studied the effect of pine dominance on the abundance of other tree species through generalized linear models.

Main results: We recorded a total of 16 tree species; a pine (Pinus montezumae) was the dominant species. The diversity of tree species was not associated with forest use or deforestation, but deforestation increased Pinus dominance, with a strong slope effect.

Research highlights: Regulation and control of forest use should be prioritized to avoid further deforestation and the transformation of species-diverse forests into monospecific forests, further increasing the dominance of P. montezumae. We also suggest reforesting with native species and those scarcely represented to increase forest cover and maintain tree diversity.

Cross species transferability of G-SSR and EST-SSR markers to Neltuma affinis Spreng.

2024-04-16T14:00:31+02:00

Aim of study: To examine the transferability of G-SSR (genomic simple sequence repeats) and EST-SSR (expressed sequence tag simple sequence repeats) markers developed for several Neltuma species to N. affinis, a species with no genomic data.

Area of study: West-Center of Entre Ríos province, Argentina. The set of molecular markers here proposed can be used to analyze samples from the entire species’ distribution range.

Material and methods: Twenty-five genomic G-SSRs and eleven EST-SSRs from multiple species were amplified in thirty N. affinis genotypes. Polymorphism, discrimination power and possible deviations from Hardy-Weinberg equilibrium were assessed.

Main results: Seventeen highly polymorphic G-SSRs were successfully transferred to N. affinis, with a PIC (polymorphic information content) average value of 0.811 and a He (expected heterozygosity) average value of 0.694; thirteen were validated, showing very low frequencies of null alleles and no linkage disequilibrium. Additionally, seven polymorphic EST-SSRs were transferred. As expected, PIC and He average values were low. Six out of seven markers were validated, and very low frequencies of null alleles and no linkage disequilibrium were observed.

Research highlights: This work provides information on the levels of microsatellites’ cross transferability to N. affinis, and its polymorphism degree. Two sets of polymorphic SSRs (genomic and expressed) to study the genetic status of the species are proposed.

Anthropogenic influences on deforestation of a peat swamp forest in Northern Borneo using remote sensing and GIS

2024-04-16T13:57:43+02:00

Aim of study: To study the anthropogenic factors that influence the fire occurrences in a peat swamp forest (PSF) in the northern part of Borneo Island.

Area of study: Klias Peninsula, Sabah Borneo Island, Malaysia.

Material and methods: Supervised classification using the maximum likelihood algorithm of multitemporal satellite imageries from the mid-80s to the early 20s was used to quantify the wetland vegetation change on Klias Peninsula. GIS-based buffering analysis was made to generate three buffer zones with distances of 1000 m, 2000 m, and 3000 m based on each of three anthropogenic factors (settlement, agriculture, and road) that influence the fire events.

Main results: The results showed that PSF, barren land, and grassland have significantly changed between 1991 and 2013. PSF plummeted by about 70% during the 19-year period. Agriculture exhibited the most significant anthropogenic factor that contributes to the deforestation of the PSF in this study area with the distance of 1001-2000 m in 1998 fire event and 0-1000 m in 2003. Additionally, the distance to settlement played an increasingly important role in the fire affected areas, as shown by the increase of weightages from 0.26 to 0.35.

Research highlights: Our results indicate that agriculture is the most influential anthropogenic factor associated with the fire-affected areas. The distance to settlement played an increasingly important role in the fire affected areas and contributes to the deforestation of the PSF in these study areas.

A new Chrysomelid-Pinaceae relationship: Calomicrus foveolatus (Coleoptera, Chrysomelidae) feeding on the Andalusian fir, Abies pinsapo (Pinaceae) in the Sierra de las Nieves National Park (Málaga, Spain)

2024-04-16T14:22:56+02:00

Aim of study: A defoliating insect, Calomicrus foveolatus, feeding on the Andalusian endemic fir Abies pinsapo (Pinaceae) is herein reported for the first time. Until now, this chrysomelid beetle was known to feed exclusively on Quercus spp. (Fagaceae).

Area of study: The study was carried out in the forests of A. pinsapo, restricted to protected mountainous areas of western Málaga and eastern Cádiz in southern Spain.

Material and methods: Since 2001 we carried out monitoring for potentially damaging insects at five sites of the pinsapo forests at least once a year. The monitoring visits were increased to 2-3 times a year at the sites that contained the phytophagous species.

Main results: Calomicrus foveolatus was observed feeding on pinsapo needles in sites of Sierra de las Nieves National Park, in Málaga province. Besides, damaged pinsapos were also observed in Sierra de Grazalema Natural Park in Cádiz Province. Feeding activity consisted of partial and superficial damage from gnawing on the upper side of the needles; eventually producing death of the needles and finally death of the entire shoot. The recognition characteristics of the beetle and its injury on the needles and branches are described.

Research highlights: It is described, for the first time, the attack of a phytophagous leaf beetle, C. foveolatus, to the endemic conifer A. pinsapo, in the National Park “Sierra de las Nieves” in the province of Málaga, Spain. Further monitoring of this beetle is necessary for the sustainable management of this protected fir endemic to the Baetic regions.

Editorial Board 33 (1)

2024-03-18T17:52:36+01:00