Economic valuation of three ecosystem services before the establishment of agreenbelt of Quebec City forest, Canada
Valoración económica de tres servicios ecosistémicos antes del establecimientode un cinturón verde alrededor de la ciudad de Quebec, Canadá
Available online: 2018-11-27
/ pages 3-15
Introduction: Forest ecosystem services provide benefits to human beings. However, it is afteran economic assessment, when such services become more relevant.
Objective: To estimate the values of three ecosystem services in the forestland around QuebecCity and compare these values with those obtained in other studies.
Materials and methods: The total cost of three ecosystem services (water supply and quality, airquality and forest habitat) was estimated to represent the value of a green belt around QuebecCity. For this, four valuation methods were used: replacement cost for water supply, cost-effectiveness for water quality, avoided cost for air quality and market price for forest habitat.
Results and discussion: The economic value corresponding to the three ecosystem services(water supply and quality, air quality and habitat) was USD 4 539.48·ha-1. Therefore, the totaleconomic value for 15,998.96 ha of the forest area around Quebec City was 72 627 025.00USD·year-1. The variation between the estimates and the values reported in other studies were theresult of different valuation methods, systems created by man as a replacement for the function ofthe forest ecosystem, the level of efficiency among the forest systems and the price sources ofmarket used for the valuation of the ecosystem.
Conclusion: The type of forest mass, the valuation method and the study context were relevantcriteria determining the ecosystem’s economic value.
Density management diagram for mixed-species forests in the El Salto region,Durango, Mexico
Diagrama de manejo de la densidad para los bosques mezclados de la región de El Salto, Durango
Available online: 2018-09-18
/ pages 17-29
Introduction: Density management diagrams (DMDs) are useful tools for characterizing andmanaging stand density.
Objective: To develop a DMD to schedule thinnings in the natural mixed-species forests of theEl Salto region, Durango.
Materials and methods: The data were collected in 441 temporary sampling plots in 263 mixed-species stands with mainly species of the Pinus and Quercus genus. The DMD was based on theHart-Becking index and a relationship of two allometric equations: 1) the quadratic meandiameter (dg, cm) with the density (N, trees·ha−1) and dominant height (Hd, m), and 2) the volume(V, m3·ha−1) with the dg, Hd and N. In fitting equations, the ordinary Nonlinear Least Squares(NLS) method was used simultaneously. The maximum density limit was estimated by potentialquantile regression that related N to Hd.
Results and discussion: Efficient goodness-of-fit statistics were reported in the fitted models, interms of Root Mean Square Error (2.29) and coefficient of determination (0.86). The DMDsuggests applying thinnings below the maximum density line to avoid mortality. Through theDMD it is possible to evaluate different silvicultural alternatives, schedule thinnings, maximizegrowth space, promote tree growth and improve forest products.
Conclusion: The DMD developed is useful for thinning scheduling to obtain saw-timber atrotation age
Identification of defects and risks in trees of San Juan de Aragon Forest, Mexico City
Identificación de defectos y riesgos en el arbolado del Bosque de San Juan de Aragón, Ciudad de México
Available online: 2018-09-24
/ pages 31-47
Introduction: Urban forests require an assessment of their trees’ structural defects, as well as the risk they represent.
Objective: To identify the defects and risks of the trees in San Juan de Aragon Forest in Mexico City.
Materials and methods: Twenty-eight circular plots of 0.1 ha were randomly established. Diameter at breast height, total height and slenderness index were measured in each tree. Structural defects were identified and a risk rating (RR) was obtained at the individual, species and section level using the methods of Matheny and Clark, and Dunster.
Results and discussion: Of the 760 trees evaluated, Casuarina equisetifolia L., Grevillea robusta A. Cunn. ex R. Br. and Hesperocyparis lusitanica Mill. were the most frequent species with diameter classes from 7.6 to 15.1 cm, heights from 5.1 to 10 m and slenderness index from 26 to 75. Structural damage was identified in 38.7 % of the trees: lean (18.8 %), cankers (15.4 %), epicormic shoots (14.4 %), dead branches (9.9 %), tumors (9.2 %) and cavities (6.2 %). Casuarina equisetifolia and Schinus molle had the highest number of defects. With the Matheny and Clark method, 83.9 % of the trees had a low RR, 14.7 % a medium RR and 1.4 % a high RR; with Dunster's method, 88.1 % had a low RR, 11.3 % a medium RR and 0.68 % a high RR.
Conclusion: The procedures for evaluating and identifying trees at risk of failure allowed recognizing their main structural defects in a simple way.
Compatible taper, volume, green weight, biomass and carbon concentrationsystem for Quercus sideroxyla Bonpl.
Sistema compatible de ahusamiento, volumen, peso verde, biomasa y concentración de carbono para Quercus sideroxyla Bonpl.
Available online: 2018-10-17
/ pages 49-69
Introduction: Estimation of total and merchantable tree volume, as well as of biomass andcarbon, implies the generation of biometric tools essential in forest management and planning.
Objectives: To fit a compatible taper, volume, green weight, dry biomass and carbonconcentration system for Quercus sideroxyla Bonpl. species using wood density.
Materials and methods: A database of 522 diameter-height measurements, obtained from 37 trees, was used in the fitting equations. The compatible system (CS) was integrated by 34 equations, which were simultaneously fitted by generalized nonlinear least squares. Taper andvolume were the base variables for estimating green weight, dry biomass and carbonconcentration.
Results and discussion: All equations were compatible with the stem volume equation, andthe merchantable equations with the taper and merchantable volume equations. The fitstatistics showed the efficiency of the equations in global terms and by relative height classes.
Conclusions: The CS has the property of estimating taper, merchantable volume, greenweight, dry biomass and carbon concentration at upper-height and by components (stem, totaltree and branches).
Optimization of a mature cotyledons-based in vitro culture system forembryogenic-callus induction in carob (Ceratonia siliqua L.)
Optimización de un sistema de cultivo in vitro basado en cotiledonesmaduros para la inducción de callos embriogénicos en algarrobo (Ceratoniasiliqua L.)
Available online: 2018-12-05
/ pages 71-84
Introduction: The carob tree (Ceratonia siliqua L.) is one of the most important plant species cultivated in the Mediterranean area. The species is in high market demand, but traditional propagation methods have not been able to satisfy it. Therefore, the use of in vitro techniques seems appropriate for the establishment of large-scale carob orchards.
Objectives: To assess the effects of five carob genotypes on embryogenic-calli induction andto optimize culture medium composition for better growth.
Materials and methods: The mature seeds of C. siliqua of the variety "Dkar", which grow infive regions of Morocco, were used as sources of explants of cotyledons. Five genotypes(‘GH’, ‘GO’, ‘GM’, ‘GA’, and ‘GB’) and four culture media (MS, B5, WPM and DKW)supplemented with three 2,4-D concentrations (2.5, 5 and 10 µM) were evaluated in this study. Sucrose and mannitol were also tested at different concentrations (0, 45, 90, 135 and180 µM).
Results and discussion: All the tested genotypes showed high callus induction levels (75 to 100 %). The Gamborg medium (B5) supplemented with 2.5 µM 2,4-D produced the highest dry weight (32.5 g) of creamy white calli. The highest amount of friable creamy-white calliwas obtained in the medium supplemented with 90 mM of sucrose. Histological analysis showed the presence of meristematic centers that became embryogenic masses and globularproembryos.
Conclusion: Mature cotyledons of C. siliqua have potential for induction and proliferation ofembryonic callus. This study aims to contribute to developing an appropriate protocol formass propagation of carob.
Germination of two varieties of Ochroma pyramidale (Cav. ex Lam.) Urb. fromthe Lacandon Jungle, Chiapas
Germinación de dos variedades de Ochroma pyramidale (Cav. ex Lam.) Urb. de la Selva Lacandona, Chiapas
Available online: 2018-10-29
/ pages 85-94
Introduction: Ochroma pyramidale (Cav. ex Lam.) Urb. is a fast-growing native species ofeconomic and ecological importance. It is currently the only species in the genus Ochroma.
Objective: To determine the effect of seven pre-germination treatments applied on seeds of O.pyramidale in its typical variety and O. pyramidale var. bicolor (Rowlee) Brizicky in theLacandon Jungle.
Materials and methods: Seven germination treatments were evaluated: control, soaking in waterat room temperature (Soaking12h and Soaking24h), immersion in boiling water at 100 °C (Boiling3sand Boiling10s) and immersion in boiling water and soaking in coconut water (Boiling3s +Soaking24h, and Boiling10s + Soaking24h). Coconut water was used as a natural source ofcytokinins.
Results and discussion: Germination of O. pyramidale in its typical variety (62 to 69 %) wasstatistically higher (P = 0.05) with treatments that included immersing the seeds in boiling water.In the case of O. pyramidale var. bicolor, the highest germination values were obtained by theBoiling3s (64 %) and Boiling3s + Soaking24h (59 %) treatments. The O. pyramidale var. bicolorseeds were susceptible to the boiling water immersion time, since germination was statisticallygreater (P = 0.05) at 3 s than at 10 s.
Conclusions: Treatments that included immersion in boiling water had a greater effect ongermination. Coconut water had no significant effect on the variable; therefore, the use ofsynthetic cytokinins is suggested in order to control the phytohormone dosage and thus verify itseffect on germination.
Obtaining microorganisms in cloud forest soils for the degradation ofaromatic hydrocarbons
Obtención de microorganismos en suelos de un bosque de niebla, para la degradación de hidrocarburos aromáticos
Available online: 2018-11-09
/ pages 95-106
Introduction: The impact of polluting substances, especially those of fossil fuels, on theenvironment is an important issue in the world. The ability of microorganisms to degradethese pollutants has been recently studied and characterized.
Objective: To analyze the ability of groups of microorganisms, obtained from a cloudforest ecosystem in Mexico, to degrade aromatic compounds (benzene, toluene,ethylbenzene and anthracene).
Materials and methods: Microbiome samples were collected in the Sierra Madre del Surin the state of Oaxaca. The microorganisms were isolated and identified by moleculartechniques. Subsequently, the ability of the microorganisms to degrade aromatichydrocarbons in a packed-bed bioreactor was quantitatively evaluated by HPLC-PDAchromatography.
Results and discussion: Fifty groups of microorganisms were collected, cultured andgenetically characterized. In genetic diversity, Lactobacillus, Prevotella and genera of the2 family Acetobacteraceae predominated. In the hydrocarbon biodegradation process, thepollutant concentration decreased 97 % and 91 % mineralization was achieved in less than25 h.
Conclusions: The microorganisms showed significant degrading activity of the aromaticcompounds. Biodiversity in the cloud forest in the Loxicha region is key to ensuringecosystem services, so it is important to undertake explorations to evaluate the use of thesebacterial microbiomes.
Water regime and gas exchange of Prosopis laevigata (Humb. & Bonpl. exWilld.) M. C. Johnst. in two semi-arid ecosystems in southern Sonora
Régimen hídrico e intercambio de gases de Prosopis laevigata (Humb. &Bonpl. ex Willd.) M. C. Johnst. en dos ecosistemas semiáridos del sur de Sonora
Available online: 2018-11-16
/ pages 107-121
Introduction: Among the adverse conditions of forest ecosystems, salinity anddrought are the abiotic factors that largely modify the genetic and productiveexpression of species.
Objective: To evaluate the effect of salinity and drought on the water regime and gasexchange of mesquite (Prosopis laevigata [Humb. & Bonpl. ex Willd.] M. C. Johnst.)in two semi-arid sites, Eco Camping and Bahía de Lobos, in southern Sonora,Mexico.
Materials and methods: The water and osmotic potentials were determined in theroot, stem and leaves of plants taken at random with similar morphological traits(height of 1.5 m and stem diameter of 0.15 m measured at 1.3 m). In addition,photosynthesis, transpiration and water-use efficiency were evaluated.
Results and discussion: Water and osmotic potentials decreased significantly (P =0.0043); the osmotic potential was the lowest in the three organs measured, forminga potential gradient, an aspect that explains the maintenance of transpiration in bothconditions (salinity and drought). Photosynthesis did not vary significantly, buttranspiration did. In both sites, water-use efficiency exceeded 6 μmol CO2/H2O;however, there was greater efficiency in the saline ecosystem due to the transpirationdecrease.
Conclusion: Mesquite has the ability to tolerate the stressful conditions of salinityand drought in southern Sonora, showing less impact in water relations and gasexchange in the salinity condition.
The role of fire in the regeneration of conifer forests
El papel del fuego en la regeneración de los bosques de coníferas
Available online: 2018-11-30
/ pages 123-139
Fire is a forest disturbance agent whose effects vary according to the natural fire regime, underwhich the species that inhabit it evolved. The aim of this paper is to present an overview of therole of fire in the regeneration of conifer forests. First, we review fire regimes and their effects ontree regeneration. Then, we describe the main methods for reconstructing fire regimes andexplore montane tropical conifer forest fire regimes. Finally, the possible effect of timberharvesting on fire regimes is described. It has been suggested that this activity is currently thedisturbance agent that has the greatest impact on fires regimes worldwide. In this review article,we propose that understanding the role of fire in the regeneration of conifer forests is essential toprevent catastrophic fires and that the use of this element as a forest management tool cancontribute to the conservation of the integrity of these forests.
Local-global and fixed-random parameters to model dominant height growthof Pinus pseudostrobus Lindley
Parámetros locales-globales y fijos-aleatorios para modelar el crecimiento enaltura dominante de Pinus pseudostrobus Lindley
Available online: 2018-12-08
/ pages 141-156
Introduction: Dominant height and site index (SI) models consider average parameters for asample or population. The dummy variable (DV) modeling approach generates global and localparameters, while mixed-effects models (MEM) generate fixed and random ones for each tree orplot.
Objective: To fit and compare dynamic dominant height equations with the DV and MEMapproaches for Pinus pseudostrobus Lindley in commercial forest plantations in Nuevo San JuanParangaricutiro, Michoacán, Mexico.
Materials and methods: Three algebraic difference approach (ADA) equations and onegeneralized algebraic difference approach (GADA) equation, based on the Chapman-Richardsmodel, were fitted with the SI parameter associated as local or random for each tree. Thedatabase used considered stem analysis of 41 trees.
Results and discussion: The accuracy of the fitted equations with DV and MEM was similar,according to the fitting statistics and the trajectories of the SI curves at the base age of 20 years.In the ADA equations, the polymorphic curve showed greater statistical efficiency with bothapproaches when the growth rate parameter depended on the SI. However, the GADA equationgenerated curves that better described the growth pattern; the highest accuracy was obtained withthe DV approach.
Conclusions: The use of the GADA equation with DV is an accurate tool for classifying theproductivity of commercial forest plantations, which will allow forest management planningbased on site quality.