ISSN e:2007-4018 / ISSN print: 2007-3828

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     Vol. XXVII, issue 2 May - August 2021   Creative Commons License

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     Vol. XXVII, issue 2 May - August 2021  

 
  

Isolated rhizobacteria of Jatropha curcas L.: antagonistic activity of phytopathogens and plant growth promoter

Rizobacterias aisladas de Jatropha curcas L.: actividad antagonista de fitopatógenos y promotora del crecimiento de plantas

Erubiel Toledo-Hernández; Guadalupe Peña-Chora; Jeiry Toribio-Jiménez; Yanet Romero-Ramírez; Alejandro Bolaños-Dircio; Miguel G. Velázquez-del Valle; Ana N. Hernández-Lauzardo; Renato León-Rodriguez; Silvana Vero

Keywords: Bacillus mojavensis; Bacillus subtilis; Bacillus thuringiensis; Pseudomonas aeruginosa; Curvularia lunata; Fusarium equiseti

10.5154/r.rchscfa.2020.04.029

Received: 2020/03/14
Accepted: 2021/01/15
Available online: 2021-01-15
Pages:181-198

Introduction: Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillus thuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equiseti was due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls (P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants.

....

Introduction: Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillus thuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equiseti was due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls (P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants.

....
 

Chemical-mechanical damage caused by the brown-rot fungus Gloeophyllum trabeum (Pers.) Murrill on Pinus pseudostrobus Lindl. wood

Daños químico-mecánicos causados por el hongo de pudrición café Gloeophyllum trabeum (Pers.) Murrill en madera de Pinus pseudostrobus Lindl.

Eduardo Días-Rivera; Wilber Montejo-Mayo; Mauro Martínez-Pacheco; Abril Munro-Rojas; Enrique Ambriz-Parra; Crisanto Velázquez-Becerra

Keywords: Wood damage; mechanical properties; sawn timber; xylophagous fungi; holocellulose

10.5154/r.rchscfa.2020.05.033

Received: 2020-05-06
Accepted: 2021-02-04
Available online: 2021-02-04
Pages:199-214

Introduction: Wood is susceptible to be used as a carbon source by various fungal species damaging the wood, by exposing the wood to different environmental conditions. Its durability has been categorized according to its weight loss, without considering the decrease of the physicochemical and mechanical properties inherent to the weight loss.

Objective: To evaluate how the weight loss in Pinus pseudostrobus Lindl. wood exposed to brown-rot fungi Gloeophyllum trabeum (Pers.) Murrill affects the physicochemical and mechanical properties.

Materials and methods: Sawn timber pieces of P. pseudostrobus were inoculated with G. trabeum. Periodically (zero, three, six and nine months) and with the help of a universal testing machine, parallel compression (PC), static bending (SB) and perpendicular compression to the grain (CPG) were evaluated, and holocellulose, cellulose and lignin were quantified.

Results and discussion: After nine months of interaction with G. trabeum, the pieces of wood were resistant to degradation, considering only weight loss. However, the chemical-mechanical properties evaluated showed that the fungus made a thinning and breakdown of the tissue cells in the wood that induced a significant decrease in the values of SB (100 to 56 N∙mm -2 ) and CPG (42.2 to 20.2 N∙mm -2 ), which reduced its resistance to mechanical stress. Such damage is not reflected in the material’s aesthetic, which is alarming, since the common user of the pinewood could not notice the problem.

Conclusions: The wood that has been exposed to fungal degradation is significantly compromised in its mechanical properties, disabling it for construction, because the chemical properties show us that the fungus causes low resistance to mechanical stress by diminishing SB and CPG.

....

Introduction: Wood is susceptible to be used as a carbon source by various fungal species damaging the wood, by exposing the wood to different environmental conditions. Its durability has been categorized according to its weight loss, without considering the decrease of the physicochemical and mechanical properties inherent to the weight loss.

Objective: To evaluate how the weight loss in Pinus pseudostrobus Lindl. wood exposed to brown-rot fungi Gloeophyllum trabeum (Pers.) Murrill affects the physicochemical and mechanical properties.

Materials and methods: Sawn timber pieces of P. pseudostrobus were inoculated with G. trabeum. Periodically (zero, three, six and nine months) and with the help of a universal testing machine, parallel compression (PC), static bending (SB) and perpendicular compression to the grain (CPG) were evaluated, and holocellulose, cellulose and lignin were quantified.

Results and discussion: After nine months of interaction with G. trabeum, the pieces of wood were resistant to degradation, considering only weight loss. However, the chemical-mechanical properties evaluated showed that the fungus made a thinning and breakdown of the tissue cells in the wood that induced a significant decrease in the values of SB (100 to 56 N∙mm -2 ) and CPG (42.2 to 20.2 N∙mm -2 ), which reduced its resistance to mechanical stress. Such damage is not reflected in the material’s aesthetic, which is alarming, since the common user of the pinewood could not notice the problem.

Conclusions: The wood that has been exposed to fungal degradation is significantly compromised in its mechanical properties, disabling it for construction, because the chemical properties show us that the fungus causes low resistance to mechanical stress by diminishing SB and CPG.

....
 

Effect of livestock on regeneration of queñoa (Polylepis australis Bitt.) forest in the Southern Andean Yungas of northwestern Argentina

Efecto del ganado sobre la regeneración del bosque de queñoa (Polylepis australis Bitt.) en las Yungas Australes del noroeste argentino

Griet An Erica Cuyckens; Flavia Mazzini; Rocío F. Julián; David E. Medina; Gustavo F. Guzmán

Keywords: restoration; seedling emergence; saplings; anthropic effect; extensive livestock

10.5154/r.rchscfa.2020.05.035

Received: 2020-05-20
Accepted: 2021-01-22
Available online: 2021-02-05
Pages:215–228

Introduction: Polylepis forest is an ecosystem stated with conservation priority and threatened by anthropogenic effects; extensive livestock is one of the most frequent disturbances in this forest. Objective: To study the effect of livestock on the early stages of regeneration of a queñoa (Polylepis australis Bitt.) forest. Materials and methods: Within a pure forest of P. australis at Parque Provincial Potrero de Yala, Jujuy, Argentina, densities of seedlings (˂1 year) and saplings (˃1 year and ˂30 cm) were measured in the presence (0.23 heads∙ha -1 ) and absence of livestock, for a year. Linear mixed models (normal distribution) were adjusted for density of seedlings and saplings. Data was analyzed with a Chi-square test (χ 2 ). Results and discussion: Presence of livestock had no impact on seedling density, but significantly decreased density of saplings (P < 0.001); in areas without livestock (10.58 ± 6.64 individuals∙m -2 ) was three times higher than with presence of livestock (3.17 ± 3.86 individuals∙m -2 ). Difference in density of seedlings and saplings was significantly (P < 0.001) over the years. This indicates that there is potential for natural regeneration, but livestock would affect stages after seedling emergence, representing a threat to the forest. Conclusion: This study provides important information for livestock management in mountain forests of P. australis. A long-term study of the effect of livestock on seedling and sapling density, and over the entire distribution range, is needed.

....

Introduction: Polylepis forest is an ecosystem stated with conservation priority and threatened by anthropogenic effects; extensive livestock is one of the most frequent disturbances in this forest. Objective: To study the effect of livestock on the early stages of regeneration of a queñoa (Polylepis australis Bitt.) forest. Materials and methods: Within a pure forest of P. australis at Parque Provincial Potrero de Yala, Jujuy, Argentina, densities of seedlings (˂1 year) and saplings (˃1 year and ˂30 cm) were measured in the presence (0.23 heads∙ha -1 ) and absence of livestock, for a year. Linear mixed models (normal distribution) were adjusted for density of seedlings and saplings. Data was analyzed with a Chi-square test (χ 2 ). Results and discussion: Presence of livestock had no impact on seedling density, but significantly decreased density of saplings (P < 0.001); in areas without livestock (10.58 ± 6.64 individuals∙m -2 ) was three times higher than with presence of livestock (3.17 ± 3.86 individuals∙m -2 ). Difference in density of seedlings and saplings was significantly (P < 0.001) over the years. This indicates that there is potential for natural regeneration, but livestock would affect stages after seedling emergence, representing a threat to the forest. Conclusion: This study provides important information for livestock management in mountain forests of P. australis. A long-term study of the effect of livestock on seedling and sapling density, and over the entire distribution range, is needed.

....
 

Seed production, dispersal and seed bank in Lupinus montanus Kunth at the upper limit of its altitudinal distribution in the Nevado de Toluca.

Producción, dispersión y banco de semillas en Lupinus montanus Kunth en el límite superior de su distribución altitudinal en el Nevado de Toluca

Diana Córdoba-Rodríguez; J. Jesús Vargas-Hernández; Francisca O. Plascencia-Escalante; Javier López-Upton; Marlín Pérez-Suárez; Carlos Trejo-López

Keywords: Fabaceae; lupine; altitudinal migration; alpine zone; soil slope

10.5154/r.rchscfa.2020.06.045

Received: 2020-06-17
Accepted: 2021-02-10
Available online: 2021-02-13
Pages:229–241

Introduction: In response to climate change, plants can adapt, migrate or die; however, migration by natural dispersion of seed can be very slow. Objective: To determine productive potential, dispersal distance and seed bank of Lupinus montanus Kunth (lupine) at the upper limit (4 200 m) of its natural distribution at the “Nevado de Toluca” mountain. Materials and methods: The seed bank was estimated in an area of 1.88 m2. Three sampling sites were established with plants in reproductive stage (15 plants) isolated from other adult plants. Seed production was determined in traps placed at the four orientations of each plant and spatial pattern of dispersal was also determined. Results and discussion: Seedbank density was 4.26 seeds∙m-2 of soil. Lupinus montanus produced over 5 500 seeds per plant in one reproductive cycle; its seed potential was associated with plant height and number of stems. The number of seeds collected varied significantly (P < 0.0001) with respect to distance from the mother plant. The dispersion curve was adjusted (P < 0.01) to a negative exponential model (R2 = 0.849). Dispersal in the four orientations was symmetrical; 97 % of the seeds fell at a distance ≤2 m from the mother plant. Conclusions: Only 3.2 % of the seeds of L. montanus reached a distance greater than 2 m from the mother plant; however, dispersal is uniform in all orientations, therefore soil slope does not represent a limiting factor for the altitudinal migration of species.

....

Introduction: In response to climate change, plants can adapt, migrate or die; however, migration by natural dispersion of seed can be very slow. Objective: To determine productive potential, dispersal distance and seed bank of Lupinus montanus Kunth (lupine) at the upper limit (4 200 m) of its natural distribution at the “Nevado de Toluca” mountain. Materials and methods: The seed bank was estimated in an area of 1.88 m2. Three sampling sites were established with plants in reproductive stage (15 plants) isolated from other adult plants. Seed production was determined in traps placed at the four orientations of each plant and spatial pattern of dispersal was also determined. Results and discussion: Seedbank density was 4.26 seeds∙m-2 of soil. Lupinus montanus produced over 5 500 seeds per plant in one reproductive cycle; its seed potential was associated with plant height and number of stems. The number of seeds collected varied significantly (P < 0.0001) with respect to distance from the mother plant. The dispersion curve was adjusted (P < 0.01) to a negative exponential model (R2 = 0.849). Dispersal in the four orientations was symmetrical; 97 % of the seeds fell at a distance ≤2 m from the mother plant. Conclusions: Only 3.2 % of the seeds of L. montanus reached a distance greater than 2 m from the mother plant; however, dispersal is uniform in all orientations, therefore soil slope does not represent a limiting factor for the altitudinal migration of species.

....
 

Impact of external and internal factors on successful grafting of Pinus pseudostrobus var. oaxacana (Mirov) Harrison

Influencia de factores externos e internos en el prendimiento inicial de injertos de Pinus pseudostrobus var. oaxacana (Mirov) Harrison

Rubén Barrera-Ramírez; J. Jesús Vargas-Hernández; Ricardo López-Aguillón; Hipólito Jesús Muñoz-Flores; Eduardo J. Treviño-Garza; Oscar A. Aguirre-Calderón

Keywords: survival; shoot growth; grafting period; side-veneers grafting; bud origin

10.5154/r.rchscfa.2020.05.037

Received: 2020-05-20
Accepted: 2021-03-09
Available online: 2021-03-11
Pages:243–256

Introduction: Grafting allows full multiplication of phenotypic and genotypic characteristics of genetically improved trees.

Objective: To determine the influence of bud origin, rootstock fertilization, grafting period and grafting techniques on the success of grafting, growth, and survival of intraspecific grafts in Pinus pseudostrobus var. oaxacana (Mirov) Harrison.

Materials and methods: The effect of four factors was evaluated ([a] two bud sources, [b] three rootstock fertilization doses, [c] three grafting seasons and [d] two grafting techniques) on the success of grafting, shoot growth (Sg) and survival. An analysis of variance was carried out to determine the effect of factors a, b, c, and d on successful grafting and Sg, and a Log-Rank test was carried out for survival analysis.

Results and discussion: Significant differences (P ≤ 0.05) were obtained for factors a,c and d. Grafting during winter (December 2018 and February 2019) using the side-veneer grafts technique and buds coming from Santa Catarina Ixtepeji showed the highest values of successful grafting (≥25.5 %), Sg (≥14.5 cm) and survival (≥20.5 %). Final survival decreased from 100 to 27 % 90 days after grafting.

Conclusions: Grafting period, bud origin, and grafting technique, individually or interacting with, are determinant factors for the success of intraspecific grafting on P. pseudostrobus var. oaxacana.

....

Introduction: Grafting allows full multiplication of phenotypic and genotypic characteristics of genetically improved trees.

Objective: To determine the influence of bud origin, rootstock fertilization, grafting period and grafting techniques on the success of grafting, growth, and survival of intraspecific grafts in Pinus pseudostrobus var. oaxacana (Mirov) Harrison.

Materials and methods: The effect of four factors was evaluated ([a] two bud sources, [b] three rootstock fertilization doses, [c] three grafting seasons and [d] two grafting techniques) on the success of grafting, shoot growth (Sg) and survival. An analysis of variance was carried out to determine the effect of factors a, b, c, and d on successful grafting and Sg, and a Log-Rank test was carried out for survival analysis.

Results and discussion: Significant differences (P ≤ 0.05) were obtained for factors a,c and d. Grafting during winter (December 2018 and February 2019) using the side-veneer grafts technique and buds coming from Santa Catarina Ixtepeji showed the highest values of successful grafting (≥25.5 %), Sg (≥14.5 cm) and survival (≥20.5 %). Final survival decreased from 100 to 27 % 90 days after grafting.

Conclusions: Grafting period, bud origin, and grafting technique, individually or interacting with, are determinant factors for the success of intraspecific grafting on P. pseudostrobus var. oaxacana.

....
 

Application of a multigranular approach based on the 2-tuple fuzzy linguistic model for the evaluation of forestry policy indicators

Aplicación de un enfoque multigranular basado en el modelo lingüístico difuso 2-tupla para la evaluación de indicadores de política forestal

José Luis Romo-Lozano; Rosa M. Rodríguez; Roberto Rendón-Medel; Álvaro Labella

Keywords: National Forest Program; qualitative assessment; fuzzy sets; linguistic hierarchies; expert panels

10.5154/r.rchscfa.2020.06.043

Received: 2020-06-17
Accepted: 2021-03-11
Available online: 2021-03-26
Pages:257–275

Introduction: The need for quality indicators is well recognized by users and proponents of public policy evaluation. Indicators recurrently include qualitative attributes for which there are few studies assessing the level of compliance. Objective: To apply a multigranular approach, based on the 2-tuple fuzzy linguistic model, to evaluate 13 indicators of the National Forestry Program, established in the system of social policy indicators derived from the National Development Plan 2012-2018 of Mexico. Materials and methods: The method uses the 2-tuple fuzzy linguistic representation model and an extension called extended linguistic hierarchies,designed to solve problems with multigranular linguistic information. The indicators'level of compliance was evaluated based on four criteria: clarity, relevance, monitoring, and adequacy. Results and discussion: The structure defined in evaluating social policy indicators corresponds appropriately to that used with the 2-tuple fuzzy linguistic model. The evaluation resulted in a sorted list in which the indicator “Rate of change of timber forest production” had the best rating with a “very high” level of compliance; 10 other indicators had the “high” level of compliance, and the remaining two indicators were rated with “moderate” compliance. Conclusions: The 2-tuple fuzzy linguistic model allowed the appropriate evaluation of the level of compliance with the desirable attributes of indicators.

....

Introduction: The need for quality indicators is well recognized by users and proponents of public policy evaluation. Indicators recurrently include qualitative attributes for which there are few studies assessing the level of compliance. Objective: To apply a multigranular approach, based on the 2-tuple fuzzy linguistic model, to evaluate 13 indicators of the National Forestry Program, established in the system of social policy indicators derived from the National Development Plan 2012-2018 of Mexico. Materials and methods: The method uses the 2-tuple fuzzy linguistic representation model and an extension called extended linguistic hierarchies,designed to solve problems with multigranular linguistic information. The indicators'level of compliance was evaluated based on four criteria: clarity, relevance, monitoring, and adequacy. Results and discussion: The structure defined in evaluating social policy indicators corresponds appropriately to that used with the 2-tuple fuzzy linguistic model. The evaluation resulted in a sorted list in which the indicator “Rate of change of timber forest production” had the best rating with a “very high” level of compliance; 10 other indicators had the “high” level of compliance, and the remaining two indicators were rated with “moderate” compliance. Conclusions: The 2-tuple fuzzy linguistic model allowed the appropriate evaluation of the level of compliance with the desirable attributes of indicators.

....
 

Interspecific grafting as an alternative for asexual propagation of Pinus rzedowskii Madrigal & Caball. Del. in danger extinction

Injerto interespecífico como alternativa para la propagación asexual de Pinus rzedowskii Madrigal & Caball. Del. en riesgo de extinción

Edgar R. Solorio-Barragán; Patricia Delgado-Valerio; Agustín Molina-Sánchez; Virginia Rebolledo-Camacho; Miguel Á. Tafolla-Martínez

Keywords: survival; phylogenetic relationships; side-veneer grafting; grafting; Pinus pinceana

10.5154/r.rchscfa.2020.06.046

Received: 2020-06-17
Accepted: 2021-03-22
Available online: 2021-04-01
Pages:277–288

Introduction: Pinus rzedowskii Madrigal & Caball. Del. is endemic to Mexico, in danger of extinction and low natural reproduction. An alternative for propagation is interspecific grafting, under the assumption that the phylogenetically more related species positively influence survival. Objectives: To evaluate grafting survival of P. rzedowskii with rootstocks of five Pinus species. Materials and methods: Interspecific grafting of P. rzedowskii with P. pinceana Gordon & Glend, P. maximartinezii Rzed, P. ayacahuite var. veitchii (Roezl) Shaw, P. pseudostrobus Lindl. and P. rzedowskii (control treatment) was carried out. The grafting method was side-veneer graft; grafting was quantified for six months and survival was evaluated using the nonparametric Kaplan-Meier method. Results and discussion: The highest final grafting survival and expected survival function were obtained with rootstocks of P. rzedowskii (85.7 ± 0.21 %; m = 0.97), followed by P. pinceana (80 ± 0.31 %; m = 0.95); P. pseudostrobus had the lowest values (20 ± 0.89 %; m = 0.66). Significant differences (P < 0.0001) were observed between P. pseudostrobus and P. maximartinezii regarding P. rzedowskii a P. pinceana. Conclusion: P. pinceana, a species phylogenetically closer to P. rzedowskii and P. maximartinezii, was the one with the highest survival rate, which may be an alternative for the rescue and ex situ conservation of P. rzedowskii.

....

Introduction: Pinus rzedowskii Madrigal & Caball. Del. is endemic to Mexico, in danger of extinction and low natural reproduction. An alternative for propagation is interspecific grafting, under the assumption that the phylogenetically more related species positively influence survival. Objectives: To evaluate grafting survival of P. rzedowskii with rootstocks of five Pinus species. Materials and methods: Interspecific grafting of P. rzedowskii with P. pinceana Gordon & Glend, P. maximartinezii Rzed, P. ayacahuite var. veitchii (Roezl) Shaw, P. pseudostrobus Lindl. and P. rzedowskii (control treatment) was carried out. The grafting method was side-veneer graft; grafting was quantified for six months and survival was evaluated using the nonparametric Kaplan-Meier method. Results and discussion: The highest final grafting survival and expected survival function were obtained with rootstocks of P. rzedowskii (85.7 ± 0.21 %; m = 0.97), followed by P. pinceana (80 ± 0.31 %; m = 0.95); P. pseudostrobus had the lowest values (20 ± 0.89 %; m = 0.66). Significant differences (P < 0.0001) were observed between P. pseudostrobus and P. maximartinezii regarding P. rzedowskii a P. pinceana. Conclusion: P. pinceana, a species phylogenetically closer to P. rzedowskii and P. maximartinezii, was the one with the highest survival rate, which may be an alternative for the rescue and ex situ conservation of P. rzedowskii.

....
 

Potential areas for silvopastoral systems based on the ecological niche of two forage crops and three species of conifers

Áreas potenciales para establecer sistemas silvopastoriles a partir del nicho ecológico de dos cultivos forrajeros y tres especies de coníferas

Jesús Eduardo Sáenz-Ceja; J. Trinidad Sáenz-Reyes; David Castillo-Quiroz; Francisco Castillo-Reyes; Hipólito Jesús Muñoz-Flores; Agustín Rueda-Sánchez

Keywords: Chloris gayana; Eragrostis curvula; Pinus devoniana; Pinus montezumae; Pinus lawsonii

10.5154/r.rchscfa.2020.07.048

Received: 2020-07-20
Accepted: 2021-03-29
Available online: 2021-04-07
Pages:289-308

Introduction: Ecological niche modeling is a fundamental tool to know the areas suitable for the establishment of silvopastoral systems, based on the environmental requirements of the species.

Objectives: To model the ecological niche of the forage species Chloris gayana Kunth and Eragrostis curvula (Schrad.) Nees, and the conifers Pinus devoniana Lindley, Pinus lawsonii Roezl ex Gordon and Pinus montezumae Lambert and to identify potential areas for silvopastoral systems.

Materials and methods: The ecological niche was modeled based on data from georeferenced collection sites in Mexico and 23 environmental variables. Subsequently, areas were identified and the extent, where forage species converge with conifers in both agricultural and forest areas, was estimated.

Results and discussion: Potential areas for silvopastoral systems with the five species were found mainly in the Neovolcanic Axis and the Sierra Madre del Sur, with a greater area suitable for agricultural areas compared to forestry areas. The ecological niche models had high predictive capacity with an area under the curve values greater than 0.93. Altitude and annual temperature range were the most important variables. Pinus devoniana had the largest potential area to be intercropped with C. gayana and E. curvula.

Conclusions: Mexico has the potential to establish silvopastoral systems with the species understudy in the center and south of the country, which could contribute to decreasing soil degradation, provide forage for livestock and maintain tree cover for agricultural and forest areas.

....

Introduction: Ecological niche modeling is a fundamental tool to know the areas suitable for the establishment of silvopastoral systems, based on the environmental requirements of the species.

Objectives: To model the ecological niche of the forage species Chloris gayana Kunth and Eragrostis curvula (Schrad.) Nees, and the conifers Pinus devoniana Lindley, Pinus lawsonii Roezl ex Gordon and Pinus montezumae Lambert and to identify potential areas for silvopastoral systems.

Materials and methods: The ecological niche was modeled based on data from georeferenced collection sites in Mexico and 23 environmental variables. Subsequently, areas were identified and the extent, where forage species converge with conifers in both agricultural and forest areas, was estimated.

Results and discussion: Potential areas for silvopastoral systems with the five species were found mainly in the Neovolcanic Axis and the Sierra Madre del Sur, with a greater area suitable for agricultural areas compared to forestry areas. The ecological niche models had high predictive capacity with an area under the curve values greater than 0.93. Altitude and annual temperature range were the most important variables. Pinus devoniana had the largest potential area to be intercropped with C. gayana and E. curvula.

Conclusions: Mexico has the potential to establish silvopastoral systems with the species understudy in the center and south of the country, which could contribute to decreasing soil degradation, provide forage for livestock and maintain tree cover for agricultural and forest areas.

....
 

Growth and water potential for Pinus patula Schltdl. & Cham. seedlings in the ejido Carbonero Jacales, Huayacocotla, Veracruz

Crecimiento y potencial hídrico en brinzales de Pinus patula Schltdl. & Cham. en el ejido Carbonero Jacales, Huayacocotla, Veracruz

Armando Falfán-Cortés; Alejandro Velázquez-Martínez; Valentín J. Reyes-Hernández; Aurelio M. Fierros-González; Gustavo Ramírez-Valverde; J. Jesús Vargas-Hernández

Keywords: Natural regeneration; tree seed methods; water deficit; forest plantations; post-planting stress

10.5154/r.rchscfa.2020.09.061

Received: 2020-09-24
Accepted: 2021-04-06
Available online: 2021-04-16
Pages:309–322

Introduction: Regeneration of forest stands under management is one of the most relevant silvicultural practices for forest cultivation.

Objective: To compare growth and water balance for both naturally regenerated and planted seedlings in Pinus patula Schltdl. & Cham. stands harvested with the seed tree method in the ejido Carbonero Jacales, Huayacocotla, Veracruz.

Materials and methods: Four sites per stand with natural regeneration and planted seedlings were selected for paired comparison. Origin and age of seedlings were recorded at each site, water potential was measured throughout the day during the dry season in 2019, also annual height and diameter growth at the base of the stem during the period 2018-2019.

Results: Naturally regenerated seedlings had significantly (P ≤ 0.01) higher annual height growth (73.8 ± 12.29 cm) compared to planted seedlings (60.8 ± 12.39 cm); the same was for diameter at stem base (20.52 ± 3.51 vs. 14.76 ± 3.54 mm). Natural regeneration also showed significantly higher (P ≤ 0.05) diurnal water deficit recovery capacity (-0.90 MPa) compared to planted seedlings (-1.06 MPa).

Conclusion: P. patula naturally regenerated seedlings had better annual growth and better physiological performance in root, which allowed a faster recovery to diurnal water deficit in foliage.

....

Introduction: Regeneration of forest stands under management is one of the most relevant silvicultural practices for forest cultivation.

Objective: To compare growth and water balance for both naturally regenerated and planted seedlings in Pinus patula Schltdl. & Cham. stands harvested with the seed tree method in the ejido Carbonero Jacales, Huayacocotla, Veracruz.

Materials and methods: Four sites per stand with natural regeneration and planted seedlings were selected for paired comparison. Origin and age of seedlings were recorded at each site, water potential was measured throughout the day during the dry season in 2019, also annual height and diameter growth at the base of the stem during the period 2018-2019.

Results: Naturally regenerated seedlings had significantly (P ≤ 0.01) higher annual height growth (73.8 ± 12.29 cm) compared to planted seedlings (60.8 ± 12.39 cm); the same was for diameter at stem base (20.52 ± 3.51 vs. 14.76 ± 3.54 mm). Natural regeneration also showed significantly higher (P ≤ 0.05) diurnal water deficit recovery capacity (-0.90 MPa) compared to planted seedlings (-1.06 MPa).

Conclusion: P. patula naturally regenerated seedlings had better annual growth and better physiological performance in root, which allowed a faster recovery to diurnal water deficit in foliage.

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Effect of land use change and agricultural management on physical and hydrological properties of an Andosol in Uruapan, Michoacán.

Efectos del cambio de uso del suelo y del manejo agrícola en las propiedades físicas e hidrológicas de un Andosol en Uruapan, Michoacán

Silvia J. Béjar-Pulido; Israel Cantú-Silva; Humberto González-Rodríguez; José G. Marmolejo-Moncivais; María I. Yáñez-Díaz; Erik O. Luna-Robles

Keywords: organic management; conventional agriculture; infiltration; Persea americana; Macadamia integrifolia

10.5154/r.rchscfa.2020.04.032

Received: 2020-04-25
Accepted: 2021-04-06
Available online: 2021-04-22
Pages:323–335

Introduction: World agriculture is characterized by intensive land use, which causes variations in physical and hydrological properties, regarded as key for agricultural productivity.

Objective: To study the effect of land use change from forest to agriculture land with organic and conventional management on the physical and hydrological properties of an Andosol.

Materials and methods: Four land use scenarios were evaluated: a forest land use scenario, two with Persea americana Mill var. Hass with conventional and organic management, and one with Macadamia integrifolia Maiden & Betche. Physical properties (texture, bulk density [BD], mechanical resistance to penetration [MRP] and porosity) and hydrological properties (moisture, hydraulic conductivity, infiltration, permanent wilting point [PWP], field capacity and available water) were determined. These variables were analyzed by parametric (ANOVA) and non-parametric (Kruskal-Wallis) statistics to determine differences among land use scenarios and depths (0 to 20 cm and 20 to 40 cm).

Results and discussion: The ANOVA showed significant differences (P ≤ 0.05) in physical and hydrological properties among land use scenarios; infiltrations decreased 40 to 70 % in agricultural systems with respect to forest use. For the depth factor, no differences were observed in the case of hydrological variables only in PWP and silt. Interaction was only significant for BD. Porosity, MRP, BD and clay defined the behavior of the hydrological variables.

Conclusions: The change from forest to agricultural land use causes significant variations in the physical and hydrological properties of an Andosol soil. The infiltration process was the most affected.

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Introduction: World agriculture is characterized by intensive land use, which causes variations in physical and hydrological properties, regarded as key for agricultural productivity.

Objective: To study the effect of land use change from forest to agriculture land with organic and conventional management on the physical and hydrological properties of an Andosol.

Materials and methods: Four land use scenarios were evaluated: a forest land use scenario, two with Persea americana Mill var. Hass with conventional and organic management, and one with Macadamia integrifolia Maiden & Betche. Physical properties (texture, bulk density [BD], mechanical resistance to penetration [MRP] and porosity) and hydrological properties (moisture, hydraulic conductivity, infiltration, permanent wilting point [PWP], field capacity and available water) were determined. These variables were analyzed by parametric (ANOVA) and non-parametric (Kruskal-Wallis) statistics to determine differences among land use scenarios and depths (0 to 20 cm and 20 to 40 cm).

Results and discussion: The ANOVA showed significant differences (P ≤ 0.05) in physical and hydrological properties among land use scenarios; infiltrations decreased 40 to 70 % in agricultural systems with respect to forest use. For the depth factor, no differences were observed in the case of hydrological variables only in PWP and silt. Interaction was only significant for BD. Porosity, MRP, BD and clay defined the behavior of the hydrological variables.

Conclusions: The change from forest to agricultural land use causes significant variations in the physical and hydrological properties of an Andosol soil. The infiltration process was the most affected.

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