Revista Bosque

Influence of sucrose and medium consistency in the in vitro multiplication and photosynthetic pigment profile of Eucalyptus saligna

Mariele Reisdörfer Schorr, Angela Cristina Ikeda, Giovana Bomfim de Alcantara — Wed, 29 Nov 2023 00:00:00 +0000

Eucalyptus saligna is one of the most cultivated species of the Eucalyptus genus for reforestation in southern Brazil as a result of genetic improvement programs to obtain clonal plantations of superior genotypes. Among the main vegetative propagation methods for recalcitrant genotypes, there is the micropropagation, which is not economically viable on large scales because of the high costs of culture media. This work aimed to test culture medium factors to reduce production costs. We tested four sucrose concentrations and two culture medium consistencies of in vitro multiplication of E. saligna and analyzed its photosynthetic pigment profile. Nodal segments of 2 cm were introduced in a Murashige and Skoog medium supplemented with 0, 15, 30, and 45 g L^-1 of sucrose at two different medium consistencies: semi-solid (7.5 g L^-1 of agar), and liquid with a spherical solid support. The experiment was completely randomized, with eight treatments in factorial scheme and four repetitions of 10 explants each. After 30 days, the mortality rate, number of shoots per explant, average shoot length, chlorophyll a, b, and total chlorophyll content were measured. The explants’ survival and multiplication rates were higher in the semi-solid medium, while the liquid medium with support was inefficient. The increase in sucrose concentration favored the formation of shoots, but there was no statistical difference between the treatments supplemented with sucrose concentrations of 15, 30, and 45 g L^-1. The higher sucrose concentration promoted significantly less chlorophyll content in the semi-solid medium.

Ecosystem hydrological dynamics in a tropical dry forest associated with a fractured environment

Wed, 29 Nov 2023 00:00:00 +0000

Tropical dry forests are seasonal ecosystems that usually develop under a very complex hydrological dynamic. In order to analyze the processes related to groundwater in these ecosystems, three micro-basins were studied on the southern coast of the state of Jalisco, Mexico, which support a dry tropical forest in a state of conservation on fractured granite, where research has been carried out on the dynamics of physical and biotic media for more than 40 years, but very little is known about the functioning of groundwater. The analysis was carried out by: 1) LiDAR images and fieldwork, 2) vegetation distribution and characterization of the fractured environment; 3) automated measurements of the precipitation-runoff response; 4) numerical simulations of the soil for the study of the infiltration process towards the fractured medium, and 5) integration and synthesis of existing multidisciplinary knowledge that adds key ecosystem components adding the physiology of the soil-plant-atmosphere continuum. The results showed that the distribution of vegetation and its phenology follows patterns that indicate the existence of local underground flows and that the process of infiltration through the soil is very fast towards the strongly fractured rock, leading to the formation of base flow in the streams. Thus, the infiltration and groundwater recharge are greater than previously considered. A basic conceptual model of water movement is proposed, which guides research on ecosystem hydrology in tropical dry forests in a markedly seasonal context.

Monitoring of forest fires at the local scale: case study of the ejido Mecayapan, Mexico

Wed, 29 Nov 2023 00:00:00 +0000

Studies focused on the monitoring of forest fires generally are based on field registers and data from satellite analysis, and very few consider both sources. However, both have limitations, like the inaccuracy of field data as well as clouds, which hamper remote sensing. The present paper revises the available sources for the identification of burnt areas of tropical rainforest, pine and oak forest in the ejido Mecayapan, Mexico, in the years 2016 to 2020. Burnt areas identified on satellite images, thermal hotspots and field data from the institutions involved in fire management were compared, using a geographic information system. The study shows that the combination of diverse sources is of great utility, allowing it to obtain a more complete vision of the total burnt surface and the ecosystems affected by wildfires. Based on this result, it is recommended to establish collaboration networks for fire monitoring, which include both actors involved in fire management and entities specialized in satellite analysis.

Morpho physiological attributes of Myracrodruon balansae seedlings in nursery: one more step for conservation

Thu, 30 Nov 2023 00:00:00 +0000

Studies that enable conservation of species at risk of extinction are needed worldwide. In this sense, seedlings for conservation purposes are essential to meet the demand for projects and planting of these species in the field. Myracrodruon balansae (Engler) D. A. Santin is a forest species native to southern Brazil, Argentina and Paraguay that lacks information on the appropriate inputs in nurseries to obtain quality seedlings. Thus, this study aimed to determine the effect of substrates and fertilizer sources on the production of M. balansae seedlings in nurseries. At 130 days after sowing, the morphophysiological attributes of the seedlings were evaluated: We observed the range of chemical and physical substrate features to enable seedlings production. Controlled release fertilizer enables the production at certain proportions of carbonized rice husk. The species tolerates the low fertility levels, and high porosity substrates, however, in such condition did not show good physiological and morphological features. Using different fertilization and carbonized rice husk affects the production time and the quality of M. balansae seedlings. The morphological and physiological characteristics demonstrated that the controlled release fertilizer 6 g L^-1 and 40% carbonized rice husk provided quality seedlings. Therefore, all the morphological and physiological variables evaluated can predict the quality of M. balansae seedlings.

Epiphytic lichen diversity on Quercus Forest from Morelos, Mexico

Xitlali Sánchez Girón, Rosa Cerros Tlaltipa, Rosa Emilia Pérez-Pérez — Thu, 30 Nov 2023 00:00:00 +0000

The diversity of lichens is related to the forest structure, and its establishment depends on the age of the phorophytes. The importance of Quercus stands out due to the anthropogenic pressure of the forests in Mexico. This study aimed to identify the Quercus species found in fragments of two Natural Protected Areas of Morelos, Mexico, and to compare the community of epiphytic lichens. We measured the phorophytes' height, crown cover, and DBH and compared their distribution with the Mann-Whitney-Wilcoxon U-test. We analyzed the richness, composition, and coverage of lichens. A first-order Jackknife nonparametric test was used, range-abundance curves were constructed, and the Shannon diversity index was applied. Among phorophytes, we used the Species Indicator Analysis and Two-Way Cluster Analysis. The results indicated that between the areas, there are differences in the composition of phorophytes. The total richness of lichens was 87 species (63 found in phorophytes). In the forest with the highest tree density, the trees were younger, with the highest richness of lichens (55); the most abundant species were Canoparmelia cryptochlorophaea, Endohyalina ericina, and Hypotrachyna gracilescens. In mature forests, tree density was lower, with only 11 species of lichen; the most abundant were Leptogium cyanescens, L. milligranum, and Physcia integrata. Only ten species are shared between the two areas. We have 20 new records.

Productivity of mini-cuttings of a hybrid clone of Eucalyptus urophylla x Eucalyptus pellita as a function of exposure time of mini-stumps to mini-tunnel

Thu, 30 Nov 2023 00:00:00 +0000

With the implementation of the mini-cutting technique in Eucalyptus, several alternatives have emerged to improve the structures for propagation, growth, and development of plants. A technology that has been used recently in the propagation of eucalyptus in clonal mini-gardens is the mini-tunnel, which has shown to be promising, making it possible to increase the productivity of the mini-stumps and also the rooting of the mini-cuttings. In this sense, this study aimed to evaluate the effect of exposure times of mini-stumps to mini-tunnel on the productivity of mini-cuttings of a hybrid clone of Eucalyptus urophylla x Eucalyptus pellita. Four times were tested: 0 (control), 15, 30, and 45 days. The total productivity and the effective productivity of mini-cuttings per mini-stump and the contents of chlorophyll a, b, and total, height, leaf area, and dry mass of the mini-cuttings were evaluated. The 45-day exposure time of the mini-stumps to the mini-tunnel resulted in greater productivity of mini-cuttings, increased height, and chlorophyll content, in addition to smaller leaf area and dry biomass of the mini-cuttings, being advantageous in the management operation of the clonal mini-garden.

Araucaria angustifolia reproductive phases in two regions of Argentina with different climate conditions

Fabiana Latorre — Wed, 29 Nov 2023 00:00:00 +0000

Araucaria angustifolia is a critically endangered species due to the reduction of its original environment and the lack of natural regeneration. The scarcity of seeds in its distribution area makes it difficult to use reforestation as a restorative measure. This work analyses climate influence on pollen and seed production. Aerobiological monitoring and seed collection were performed in two regions of Argentina: San Antonio (SA), Misiones, a subtropical site; and 25 de Mayo (25M), Buenos Aires, a temperate area. The seasonality of pollination was similar between sites (spring). However, pollen amount was four times higher in 25M, with high hourly values throughout the day, and a shorter duration of about half the number of days in relation to SA. Seed production was also higher in 25M (six fold). Reproduction proved to be favoured by temperate climate because of higher summer temperatures prior to pollination (period of strobili initiation), lower winter temperatures (during the pollen grain formation), and lower rainfall during pollen transport. Management guidelines involving ex-situ conservation of this native forest species are proposed.

Evaluation in Peumus boldus trees after 10 years since the harvest: Response in a megadrought scenario

Wed, 29 Nov 2023 00:00:00 +0000

Peumus boldus (boldo) is an important tree in the mediterranean forests of central Chile. Its leaves are valued for their essential oils and alkaloids. Historically, and in various sectors, the harvest of boldo leaves has been superior to natural production. Additionally, the megadrought that has affected these forests since 2010 is see as a threat. Therefore, it is necessary to determine sustainable harvest levels for the management of natural formations with boldo. The objective of the study was to evaluate the recovery of boldos harvested in 2011, in the Metropolitan Region of Chile. The study was carried out in trees with partial harvest, total harvest, and no harvest. Pre-dawn and noon water potential, chlorophyll fluorescence, and growth were evaluated. After 8 years there were still differences between the treatments, where a higher harvest intensity implied a better water condition of the trees. Between 2011 and 2021, partially and fully harvested trees recovered an average of 10.7% and 24.2% of their initial biomass, respectively. The trees without harvest had an average loss of 0.9% compared to the initial biomass recorded in 2011. The reduction of above-ground biomass has been more accelerated since 2019. In the megadrought scenario, it is expected that the growth in boldo will be lower than that reported so far. The climatic conditions in central Chile establish the need to review the harvesting methods and periodicity currently used for boldo.

Effects of tropical montane forest restoration on the ecohydrological functioning of watersheds

Marcela Mosquera Vasquez — Thu, 30 Nov 2023 00:00:00 +0000

At the global level, ecological restoration is becoming increasingly important, given the degraded conditions of ecosystems and, therefore, the urgent need to recover these ecosystems and reestablish ecosystem services and forest biodiversity. Specifically, tropical forests have been degrading at accelerated rates, to date there are very few studies that have evaluated the effects of forest restoration programs on soil properties and ecohydrological functioning of tropical ecosystems. The objective of this research was to evaluate the ecohydrological processes in low montane moist forest (bh-MB) watersheds subjected to ecological restoration (El Silencio and Montañita), compared to one with pastures (Pastos), and to characterize the variables that determine these processes in the emerging ecosystems. In each watershed, climatic variables were monitored, and the physical, hydraulic and organic matter properties of the soil and ecohydrological variables were measured. The results indicate that the watersheds under the restoration program show a tendency to recover the initial conditions of soil properties, which favors the regulation of summer flows and reduces storm flows; while the pasture watershed shows a tendency to degraded soils. It is concluded that the natural regeneration process of the forest in areas dedicated to extensive cattle raising contributes to improve the physical conditions of the soil, which favors the recharge of water to the aquifers and sustains the base flow in times of low precipitation.

Historic urban trees: assessment of the internal integrity of the stem

Wed, 29 Nov 2023 00:00:00 +0000

In addition to the benefits that all trees provide, in general, the cultural and affective value that historic urban trees provide contributes to the quality of life in cities. As they age, care for their maintenance must be careful and constant, aiming to reduce the associated risks. Thus, the objective of the present study was to identify and estimate the extent of internal areas injured in the trunk of historic urban trees. Forty-five Eucalyptus robusta trees located in a popular square in the city of Nova Friburgo-RJ/Brazil were evaluated. A visual analysis of the crown, trunk, and root system was performed, followed by complementary evaluations of acoustic tomography and resistography, when necessary. Mathematical models were adjusted in order to infer the relationship and influence of dendrometric characteristics (total height, height to the first branch, diameter at 1.30 m above the ground, and crown diameter) and the mean resistographic amplitude on the mean wave propagation velocity acoustic. Most trees presented some type of external lesion on the trunk and, in general, trees with severe lesions also presented alterations in the propagation velocity of acoustic waves and in the perforation resistance profile. Thus, the combination of different assessment techniques helps in the identification of internal lesions in the trunk of urban trees, including mature and historical ones.

Assessing deforestation in a southeast region of Jalisco, Mexico with the BFAST algorithm and Collect Earth

Thu, 30 Nov 2023 00:00:00 +0000

The forest regions of the state of Jalisco are being impacted by increasingly frequent changes in land use, the southeast region has not been the exception, in recent years the increase in deforestation is more visible due to the increase in the number of avocado crops in forest areas, currently there are no studies that use precise methods to estimate deforestation in the area in recent years. Through the multitemporal analysis of Landsat-NDVI images with the BFAST algorithm, preliminary changes in forest cover were estimated in a period of 18 years starting in the year 2000 and through high-resolution images and the tools contained in Collect Earth were validated these changes, thus recording the coverage after the change, the year, and any other disturbance associated. With the resulting map, the accuracy was calculated by map classes and the deforested area was adjusted, finally the annual deforestation rate was calculated with the FAO equation, in order to make these results comparable with other areas with similar dynamics. The results show a deforestation of 3,834 ha in a period of eighteen years, which represents a deforestation rate of 0.19% per year, being the largest of these changes towards agricultural land, mainly in the pine and pine-oak covers, in low deciduous forest was only expansion of already existing agricultural areas and frequent fires. The overall accuracy of the map was 82.5 %.

Estimation of genetic parameters for productive traits in Eucalyptus tereticornis and implications for breeding

Milena González — Tue, 28 Nov 2023 00:00:00 +0000

Eucalyptus tereticornis exhibits adaptation to a wide range of soils and environments, making it suitable for various protective and productive purposes throughout the territory of Uruguay. Due to the absence of a locally improved seed source, INIA began a tree breeding program in 2007 using genetic material from two sources: the natural distribution area of the species and local plantations. The performance of the genetic pool was evaluated at different sites over a nine-year growth period. The objectives of this study were to estimate genetic parameters (heritability, genetic correlations, and genotype-by-environment interaction) for growth and stem form traits and to estimate the genetic gains achievable through selection at different ages, in order to guide the breeding strategy for E. tereticornis. The genotype-environment interaction for volume and survival exhibited moderate to low levels, with Type B genetic correlations ranging from 0.68 to 0.82. The combined analysis of the trials revealed that heritability increased with the age of measurement for all traits, with values ranging from low to moderate for growth variables (0.04 – 0.23) and stem form (stem straightness and forking) showing low values (0.05 – 0.12). Genetic correlations between growth traits at different ages and volume at 9 years were positive and high (0.32 – 0.99), while the correlations between stem form (stem straightness and forking) and volume were low to moderate (0.30 – 0.56). The results obtained suggest that it is possible establish a single breeding unit and that through early selection, genetic gains can be maximized, evaluation costs reduced, and improved seed obtained in a shorter timeframe.

Statistical properties of three estimators in the context of the rotating panel design of the National Forest and Soil Inventory of Mexico

Tue, 28 Nov 2023 00:00:00 +0000

From a re-measurement perspective, the sampling design of the National Forests and Soil Inventory (INFyS) consists of rotating panels or panelized samples, from which only the 20 % of the total sample is collected each year over a five-year period. To explore the most suitable statistical methods for the rotating panelized design, an evaluation of three sampling estimators was conducted: generalized least squares (MCG), replicated sampling (MRE) and the univariate composite estimator (ECU). The specific forest parameter examined in this study was the average basal area observed across two measurement cycles: 2004 - 2007 and 2009 - 2012. The data used in this analysis, drawn from the INFyS, represented an artificial population, combining the data acquired in the states of Durango, Quintana Roo, Hidalgo, Jalisco, Estado de Mexico, Chihuahua and Michoacán and spanning 7,597 panelized conglomerates. The performance of the proposed estimators was evaluated for each measurement cycle, involving the generation of 100 random samples, each with sizes of 1,000 and 1,500. Results show that, despite a slight bias, the MCG estimator exhibited lower variance compared to the MRE. In each sample, the ECU estimator displayed a relative estimation bias that struck a balance between the MCG and MRE, while maintaining lower variance than the MRE. Under these conditions, the ECU estimator can be regarded as a minimum variance quasi-unbiased estimator. The adoption of the ECU estimator has the potential to reduce costs and sampling efforts across re-measurement cycles without compromising statistical precision.

Arbuscular mycorrhizal fungi dynamics during natural succession in mining-impacted areas of a tropical rainforest in Chocó, Colombia

Tue, 28 Nov 2023 00:00:00 +0000

Soils impacted by mining undergo significant alterations that affect their revegetation potential. One important alteration is the reduction of key microbial symbionts, such as arbuscular mycorrhizal fungi (AMF), which have the capacity to facilitate soil revegetation through symbiotic relationships with plants. This study aimed to assess changes in the AMF community composition during the natural succession of mining-impacted areas in Condoto, Chocó, Colombia. Researchers selected three mines abandoned for 5, 15, and 30 years, along with a natural reference forest. Soil samples were collected to evaluate fertility and quantify AMF spore populations, and fine root samples of three woody species were collected to quantify AMF colonization, including number of hyphae, vesicles, and arbuscules. The successional sites exhibited acidic and nutrient-poor soils. Fifteen AMF morphotypes were identified, with Acaulospora and Glomus being the most abundant genera. However, the diversity and composition of morphotypes, as well as the abundance of hyphae, vesicles, and arbuscules in roots did not differ significantly between treatments. The presence of AMF in early stages of mine abandonment suggests a potential role in expediting natural revegetation. However gaining a deeper understanding of the role played by this edaphic biotic community in mine restoration will require future research that examines the specific interactions between AMF species and plants in this unique environment throughout the natural succession process.

Charcoal anatomy of seven species from an Araucaria Forest area in Southern Brazil

Tue, 28 Nov 2023 00:00:00 +0000

Con el objetivo de brindar información que apoye la identificación de especies y el control de la producción ilegal de carbón, este trabajo tuvo como objetivo caracterizar anatómicamente la madera carbonizada de las especies Nectandra megapotamica, Ocotea indecora, Ocotea diospyrifolia, Ocotea puberula, Balfourodendron riedelianum, Chrysophyllum marginatum y Zanthoxylum rhoifolium, nativas de las áreas del Bosque de Araucaria. Las muestras fueron colectadas en la región del Planalto Catarinense (altiplano del estado de Santa Catarina). Se extrajeron tres discos de tres árboles de cada especie, seleccionados al azar. Todos los discos se seccionaron para obtener muestras cercanas a las diferentes posiciones del tronco (cerca de la corteza, intermedia y cerca de la médula), las cuales se carbonizaron durante 392 minutos en un horno de mufla en régimen de rampa y temperatura máxima de 450 ºC. Después de la carbonización, no hubo una degradación significativa de la estructura anatómica y la disposición de las células, lo que permitió caracterizar e identificar las especies en comparación con las referencias de descripción de la madera. La posición de las muestras en el tronco no influyó en las características anatómicas, lo que permitió la identificación de especies. La madera de la familia Lauraceae presentó mayor diámetro de vasos y menor frecuencia de vasos en comparación con las muestras de las familias Rutaceae y Sapotaceae. La agrupación de vasos, el ancho y la frecuencia de los rayos podrían discriminar a Chrysophyllum marginatum de las otras especies evaluadas. Los resultados obtenidos contribuyen a una base de datos de carbón vegetal de especies del Bosque de Araucaria que se puede consultar para aplicaciones prácticas en la supervisión forestal.

Needs to effectively carry out ecological restoration processes in Ecuador

Tue, 28 Nov 2023 00:00:00 +0000

During the Third Ecuadorian National Congress on Landscape Restoration (CERP 2021), the Tropical Research Center on Environment and Biodiversity of the Universidad Nacional de Loja organized a workshop to promote dialog to discuss the ecological restoration needs that the country must address. The workshop relied on the virtual presence of participants from NGOs, governmental organizations, private enterprises, local farmers, and researchers, as well as about 100 attendees, who also presented their opinions in the virtual platform. According to the participants, the priorities in Ecuador are: i) creation of manuals for identification of suitable perennial plant species in every Ecuadorian ecosystem and in accordance with the specific restoration goals, ii) a compilation of restoration techniques (considering the ecosystem and local knowledge), iii) inclusion of non-vascular plants from early successional stages, iv) exploration of plant-animal interactions, v) monitoring of restoration practices, vi) inclusion of the socioeconomic aspects of restoration, vii) incorporation of the forest landscape restoration approach, viii) research of propagation strategies, ix) evaluation of effectiveness of policies and laws regarding restoration, and x) improving compatibility of restoration with productive activities. Participants proposed the compilation of all research priorities in a national research agenda on restoration, and the significant improvement of knowledge transfer and dissemination.

Classification systems for secondary forests in four neotropical countries: Synthesis and conceptual analysis

Fábio Fiamoncini-Pastório, Kristiana Fiorentin-dos-Santos, André Luís de-Gasper — Tue, 28 Nov 2023 00:00:00 +0000

A forest successional stage classification system is an important tool for forest management and ecosystem protection. This review aimed to compare the legal definitions and classifications of primary and secondary forests adopted by four tropical countries: Brazil, Argentina, Panama, and Costa Rica. Two socio-economic and four structural criteria were established and compared among the countries. Only Argentina clearly underpins its ratings with scientific studies, and only in this country do social groups participate in the development of the law. Brazil and Argentina had the highest number of parameters to differentiate forest types. According to our findings, we encourage all countries to update their legal systems based on scientific information and include popular participation in the discussion. This would reduce conflicts of interest and allow for a better reconciliation of forest conservation and sustainable development.