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

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     Articles in press, 2022   Creative Commons License

      
 

     Vol. -, issue - publicación en avanzada - 2022  

 
  

Does the severity of a forest fire modify the composition, diversity and structure of temperate forests in Jalisco?

¿La severidad de un incendio forestal modifica la composición, diversidad y estructura de los bosques templados de Jalisco?

Keywords: fire; Pinus devoniana; Quercus; diversity indices; vegetation structure

10.5154/r.rchscfa.2020.12.076

Received: 2020-12-16
Accepted: 2021-09-29
Available online: 2021-11-09
Pages:000-000

Introduction: Forest fires are natural disturbances that influence structure, dynamics, performance, composition and diversity of species.

Objective: To compare composition, structure and diversity of temperate forest vegetation affected by different levels of severity of a forest fire in Jalisco.

Materials and methods: Composition, horizontal structure, importance value index (IVI), diameter class, diversity indexes of Shannon, Simpson, Margalef richness and Bray-Curtis similarity were evaluated in three regions (Bosque La Primavera and Sierra de Tapalpa and Sierra de Quila) of temperate forest with three levels of severity (no fire, moderate and extreme).

Results: Twelve species from six families were recorded. Pinaceae and Fagaceae were the most dominant. Dominance ranged from 0.2 to 50 m2 ∙ha-1 in moderate and extreme severity sites. Pinus devoniana recorded the highest IVI (71 %) in Sierra de Tapalpa. The highest number of trees was recorded in diameter class ≤30 cm. Diversity and richness indices showed significant differences (P < 0.05) for Sierra de Tapalpa and Sierra de Quila and among fire levels; the highest indices were recorded in sites of moderate severity. Tree composition similarity between regions was low (<33 %).

Conclusions: Moderate severity of forest fire favored composition, structure and diversity of vegetation in temperate forests of Jalisco, indicating that the level of severity influences resilience of forest ecosystem communities.

....

Introduction: Forest fires are natural disturbances that influence structure, dynamics, performance, composition and diversity of species.

Objective: To compare composition, structure and diversity of temperate forest vegetation affected by different levels of severity of a forest fire in Jalisco.

Materials and methods: Composition, horizontal structure, importance value index (IVI), diameter class, diversity indexes of Shannon, Simpson, Margalef richness and Bray-Curtis similarity were evaluated in three regions (Bosque La Primavera and Sierra de Tapalpa and Sierra de Quila) of temperate forest with three levels of severity (no fire, moderate and extreme).

Results: Twelve species from six families were recorded. Pinaceae and Fagaceae were the most dominant. Dominance ranged from 0.2 to 50 m2 ∙ha-1 in moderate and extreme severity sites. Pinus devoniana recorded the highest IVI (71 %) in Sierra de Tapalpa. The highest number of trees was recorded in diameter class ≤30 cm. Diversity and richness indices showed significant differences (P < 0.05) for Sierra de Tapalpa and Sierra de Quila and among fire levels; the highest indices were recorded in sites of moderate severity. Tree composition similarity between regions was low (<33 %).

Conclusions: Moderate severity of forest fire favored composition, structure and diversity of vegetation in temperate forests of Jalisco, indicating that the level of severity influences resilience of forest ecosystem communities.

....
 

Fertilization of two genetic groups of Pinus patula Schiede ex Schltdl. & Cham. in a four-year progeny trial

Fertilización de dos grupos genéticos de Pinus patula Schiede ex Schltdl. & Cham. en un ensayo de progenies de cuatro años

Keywords: controlled-release fertilizer; genotypes; forest nutrition; growth rate; foliar analysis

10.5154/r.rchscfa.2020.08.049

Received: 2020-08-14
Accepted: 2021-09-30
Available online: 2021-11-01
Pages:000-000

Introduction: Genetic improvement and nutritional management are used to increase productive capacity.

Objective: To analyze the effect of traditional and controlled-release fertilizers, as well as the way to define the doses (technically or empirically), on growth of 20 tree families of Pinus patula Schiede ex Schltdl. & Cham.

Materials and methods: Four fertilization treatments were applied: 1) control; 2) “technical”, based on foliar analysis; 3) controlled release (18-6-12 + 2CaO + 3.5 Mg + 2.1 Si + microelements); and 4) mixture of agricultural fertilizers in nutrient concentrations similar to the controlled-release treatment. Height, diameter, biomass index, number of whorls, leaf mass, and growth initiation and cessation were evaluated in a group of 10 superior and 10 inferior three-year old families in Chignahuapan, Puebla. Data were analyzed with the MIXED procedure of SAS.

Results and discussion: Trees showed no significant differences in growth, biomass production and growth initiation by fertilization effect, but showed significant differences by genetic quality (P ≤ 0.05). The genotype*fertilization interaction was significant; after one year of controlled-release fertilizer application, inferior genotypes had the highest values of relative rates of biomass production, diameter at root collar and height.

Conclusions: Controlled-release fertilizers at appropriate doses and environmental conditions are a viable option to promote growth of young P. patula trees in the field.

....

Introduction: Genetic improvement and nutritional management are used to increase productive capacity.

Objective: To analyze the effect of traditional and controlled-release fertilizers, as well as the way to define the doses (technically or empirically), on growth of 20 tree families of Pinus patula Schiede ex Schltdl. & Cham.

Materials and methods: Four fertilization treatments were applied: 1) control; 2) “technical”, based on foliar analysis; 3) controlled release (18-6-12 + 2CaO + 3.5 Mg + 2.1 Si + microelements); and 4) mixture of agricultural fertilizers in nutrient concentrations similar to the controlled-release treatment. Height, diameter, biomass index, number of whorls, leaf mass, and growth initiation and cessation were evaluated in a group of 10 superior and 10 inferior three-year old families in Chignahuapan, Puebla. Data were analyzed with the MIXED procedure of SAS.

Results and discussion: Trees showed no significant differences in growth, biomass production and growth initiation by fertilization effect, but showed significant differences by genetic quality (P ≤ 0.05). The genotype*fertilization interaction was significant; after one year of controlled-release fertilizer application, inferior genotypes had the highest values of relative rates of biomass production, diameter at root collar and height.

Conclusions: Controlled-release fertilizers at appropriate doses and environmental conditions are a viable option to promote growth of young P. patula trees in the field.

....
 

Risk of infestations by Dendroctonus mexicanus Hopkins and Dendroctonus frontalis Zimmermann bark beetles in forests of Michoacán

Riesgo de infestaciones por los descortezadores Dendroctonus mexicanus Hopkins y Dendroctonus frontalis Zimmermann en bosques de Michoacán

Keywords: Climate change; spatial modeling; conifer insects; forest pest; Analytic Hierarchy Process

10.5154/r.rchscfa.2020.11.069

Received: 2020-11-17
Accepted: 2021-10-04
Available online: 2021-11-02
Pages:000-000

Introduction: Severe Dendroctonus spp. infestations are reported in North and Central America. Dendroctonus mexicanus Hopkins and Dendroctonus frontalis Zimmermann are recognized as forest pests and are common in the state of Michoacán, Mexico.

Objective: To model current and future (2015-2039) spatial distribution of risk of D. mexicanus and D. frontalis infestation in forests of Michoacán, Mexico.

Materials and methods: Multicriteria evaluation techniques, including the analytic hierarchy process and fuzzy membership functions, were combined with climate and biophysical variables to obtain forest infestation risk maps for D. mexicanus and D. frontalis under current and future climate scenarios.

Results and discussion: Climate, fire, tree density and topography were identified as relevant criteria influencing bark beetle outbreaks. The maximum risk value estimated for D. mexicanus was 0.78 and 0.83 for the current and future scenarios, respectively; for D. frontalis these values correspond to 0.84 and 0.85, respectively. In terms of area, high risk of infestation by D. mexicanus increased from 3.9 % (current scenario) to 5.0 % (future scenario); for D. frontalis it decreased from 10.8 % to 9.6 %. The very high-risk value remained constant (0.35 %) for both species and scenarios

Conclusions: Forests of the Transversal Volcanic Belt (in the northeastern part of Michoacán) have the highest risk of bark beetle infestation in the two modeled scenarios.

....

Introduction: Severe Dendroctonus spp. infestations are reported in North and Central America. Dendroctonus mexicanus Hopkins and Dendroctonus frontalis Zimmermann are recognized as forest pests and are common in the state of Michoacán, Mexico.

Objective: To model current and future (2015-2039) spatial distribution of risk of D. mexicanus and D. frontalis infestation in forests of Michoacán, Mexico.

Materials and methods: Multicriteria evaluation techniques, including the analytic hierarchy process and fuzzy membership functions, were combined with climate and biophysical variables to obtain forest infestation risk maps for D. mexicanus and D. frontalis under current and future climate scenarios.

Results and discussion: Climate, fire, tree density and topography were identified as relevant criteria influencing bark beetle outbreaks. The maximum risk value estimated for D. mexicanus was 0.78 and 0.83 for the current and future scenarios, respectively; for D. frontalis these values correspond to 0.84 and 0.85, respectively. In terms of area, high risk of infestation by D. mexicanus increased from 3.9 % (current scenario) to 5.0 % (future scenario); for D. frontalis it decreased from 10.8 % to 9.6 %. The very high-risk value remained constant (0.35 %) for both species and scenarios

Conclusions: Forests of the Transversal Volcanic Belt (in the northeastern part of Michoacán) have the highest risk of bark beetle infestation in the two modeled scenarios.

....
 

Stoichiometry of needle litterfall of Pinus hartwegii Lindl. in two alpine forests of central Mexico

Estequiometría de la caída de acículas de Pinus hartwegii Lindl. en dos bosques alpinos del centro de México

Keywords: leaf mass; forest floor; nutrient flux; pine; climate change; climate change

10.5154/r.rchscfa.2020.12.077

Received: 2020-12-16
Accepted: 2021-10-11
Available online: 2021-11-03
Pages:000-000

Introduction: It is essential to have baselines on nutrient dynamics in forests, due to disturbances that climate change may cause.

Objective: To quantify the annual production of needles of Pinus hartwegii Lindl. and the proportion of nutrients in the alpine forests of Jocotitlán (JO) and Tláloc (TL) mountains, Estado de México.

Materials and methods: A total of 12 circular needle litter traps (30 cm diameter) were placed at ground level, in each forest, distributed in four topographically contrasting sites. For one year, 228 leaf mass measurements and 1 140 chemical determinations were made to determine needle stoichiometry. Measurements were subjected to a longitudinal analysis of variance, by testing trends over time (P < 0.05).

Results and discussion: Needle production in JO were 67 % higher (11.2 Mg∙ha -1 ∙year - 1 ) than in TL (6.7 Mg∙ha -1 ∙year -1 ); needle litterfall was higher during summer (June and July, months with higher precipitation). For JO, nutrient flux was 98.0, 5.2, 8.7, 24.6, and 5.6 kg∙ha -1 ∙year -1 for N, P, K, Ca, and Mg, respectively; for TL it was 55.3, 3.4, 7.8, 14.4, and 4.7 kg∙ha -1 ∙year -1 in the same order of nutrients. Nutrient concentrations were lower from March to May. Except for K, nutrient concentrations and needle production showed quadratic and cubic seasonal trends. Mg dynamics and N:Mg and N:K ratios in TL were more positive for tree growth.

Conclusions: Jocotitlán and Tláloc forests produce significant needle mass (compared to other ecosystems) with high dynamic in nutrient transfers.

....

Introduction: It is essential to have baselines on nutrient dynamics in forests, due to disturbances that climate change may cause.

Objective: To quantify the annual production of needles of Pinus hartwegii Lindl. and the proportion of nutrients in the alpine forests of Jocotitlán (JO) and Tláloc (TL) mountains, Estado de México.

Materials and methods: A total of 12 circular needle litter traps (30 cm diameter) were placed at ground level, in each forest, distributed in four topographically contrasting sites. For one year, 228 leaf mass measurements and 1 140 chemical determinations were made to determine needle stoichiometry. Measurements were subjected to a longitudinal analysis of variance, by testing trends over time (P < 0.05).

Results and discussion: Needle production in JO were 67 % higher (11.2 Mg∙ha -1 ∙year - 1 ) than in TL (6.7 Mg∙ha -1 ∙year -1 ); needle litterfall was higher during summer (June and July, months with higher precipitation). For JO, nutrient flux was 98.0, 5.2, 8.7, 24.6, and 5.6 kg∙ha -1 ∙year -1 for N, P, K, Ca, and Mg, respectively; for TL it was 55.3, 3.4, 7.8, 14.4, and 4.7 kg∙ha -1 ∙year -1 in the same order of nutrients. Nutrient concentrations were lower from March to May. Except for K, nutrient concentrations and needle production showed quadratic and cubic seasonal trends. Mg dynamics and N:Mg and N:K ratios in TL were more positive for tree growth.

Conclusions: Jocotitlán and Tláloc forests produce significant needle mass (compared to other ecosystems) with high dynamic in nutrient transfers.

....
 

Genetic parameters of a progeny trial of Pinus greggii Engelmann ex Parlatore var. australis Donahue & López in the Mixteca Alta of Oaxaca, Mexico.

Parámetros genéticos de un ensayo de progenies de Pinus greggii Engelmann ex Parlatore var. australis Donahue & López en la Mixteca Alta de Oaxaca, México

Keywords: genetic control; heritability; stem straightness; genetic correlation; superior trees

10.5154/r.rchscfa.2020.10.067

Received: 2020-10-30
Accepted: 2021-10-22
Available online: 2021-11-12
Pages:000-000

Introduction: The Mixteca Alta of Oaxaca has high environmental degradation. Several species have been planted to recover vegetation cover; Pinus greggii Engelmann ex Parlatore var. australis Donahue & López has grown successfully even without selected material.

Objective: To determine growth performance and genetic parameters of 90 families at early ages, for use in the selection of superior trees.

Materials and methods: In San Miguel Achiutla, Oaxaca, genetic variation in growth, conformation and straightness of 90 selected open-pollinated families of P. greggii var. australis was evaluated in a progeny trial five years after planting in two different quality sites. Additive genetic variation, heritability (h 2 ) and genetic and phenotypic correlations were calculated.

Results and discussion: h 2 were superior in the more fertile site. Height, whorls, straightness and volume had greater genetic control (0.09 < h 2 i < 0.18). h 2 i of stem straightness was higher when evaluated as a whole than when divided into three sections. Genetic correlations were high and positive among growth variables (r g > 0.81; diameter vs. volume = 0.99) and low to moderate for the rest. Volume had a higher genetic correlation with other traits and higher genetic variation and heritability, so it could be used as a selection criterion for breeding cycle. Some genetic correlations differed contrastingly between sites in equal pairs of variables.

Conclusion: Differences between families and heritability will allow the identification of superior individuals for germplasm sources for regional use.

....

Introduction: The Mixteca Alta of Oaxaca has high environmental degradation. Several species have been planted to recover vegetation cover; Pinus greggii Engelmann ex Parlatore var. australis Donahue & López has grown successfully even without selected material.

Objective: To determine growth performance and genetic parameters of 90 families at early ages, for use in the selection of superior trees.

Materials and methods: In San Miguel Achiutla, Oaxaca, genetic variation in growth, conformation and straightness of 90 selected open-pollinated families of P. greggii var. australis was evaluated in a progeny trial five years after planting in two different quality sites. Additive genetic variation, heritability (h 2 ) and genetic and phenotypic correlations were calculated.

Results and discussion: h 2 were superior in the more fertile site. Height, whorls, straightness and volume had greater genetic control (0.09 < h 2 i < 0.18). h 2 i of stem straightness was higher when evaluated as a whole than when divided into three sections. Genetic correlations were high and positive among growth variables (r g > 0.81; diameter vs. volume = 0.99) and low to moderate for the rest. Volume had a higher genetic correlation with other traits and higher genetic variation and heritability, so it could be used as a selection criterion for breeding cycle. Some genetic correlations differed contrastingly between sites in equal pairs of variables.

Conclusion: Differences between families and heritability will allow the identification of superior individuals for germplasm sources for regional use.

....
 

Water supply and water runoff quality in the sub deciduous forest of the Coast of Oaxaca, Mexico.

Suministro y calidad del agua de escurrimientos en la selva mediana subcaducifolia de la Costa de Oaxaca, México

Keywords: contaminated water, vegetation cover; runoff; micro-watershed; physicochemical quality

10.5154/r.rchscfa.2020.10.063

Received: 2020-10-24
Accepted: 2021-11-02
Available online: 2021-11-18
Pages:000-000

Introduction: Land use change and waste discharge from coffee processing may be affecting quantity and quality of water supplying urban areas in the coastal region of Oaxaca.

Objective: To determine the level of contamination of aquifers and estimate surface water runoff in micro-watersheds of Pluma Hidalgo and Santa María Huatulco in Oaxaca, Mexico.

Materials and methods: Seven water supply points were analyzed during the rainy season of 2019. The following physicochemical parameters were determined: pH, total dissolved solids, electrical conductivity, hardness, total solids, chlorides, and chemical oxygen demand (COD). Surface runoff was estimated using the Raws and Prevert methods.

Results and discussion: Water bodies are within the permissible limits for human use. The Chacalapilla spring was classified as moderately hard (85 mg CaCO 3 ∙L -1 ), while the seven water bodies exceeded the permissible limit for COD (40 to 200 mg∙L -1 ); therefore, water is in a contaminated classification range and is not suitable for human consumption. Surface runoff values suggest a medium conservation condition of vegetation cover; areas with higher cover recorded lower runoff coefficients.

Conclusions: The physicochemical parameters indicated that water from Pluma Hidalgo and Santa María Huatulco is suitable for human use, but not for drinking.

....

Introduction: Land use change and waste discharge from coffee processing may be affecting quantity and quality of water supplying urban areas in the coastal region of Oaxaca.

Objective: To determine the level of contamination of aquifers and estimate surface water runoff in micro-watersheds of Pluma Hidalgo and Santa María Huatulco in Oaxaca, Mexico.

Materials and methods: Seven water supply points were analyzed during the rainy season of 2019. The following physicochemical parameters were determined: pH, total dissolved solids, electrical conductivity, hardness, total solids, chlorides, and chemical oxygen demand (COD). Surface runoff was estimated using the Raws and Prevert methods.

Results and discussion: Water bodies are within the permissible limits for human use. The Chacalapilla spring was classified as moderately hard (85 mg CaCO 3 ∙L -1 ), while the seven water bodies exceeded the permissible limit for COD (40 to 200 mg∙L -1 ); therefore, water is in a contaminated classification range and is not suitable for human consumption. Surface runoff values suggest a medium conservation condition of vegetation cover; areas with higher cover recorded lower runoff coefficients.

Conclusions: The physicochemical parameters indicated that water from Pluma Hidalgo and Santa María Huatulco is suitable for human use, but not for drinking.

....