Introduction: In the nursery, controlled-release fertilization and inoculation with mycorrhizal fungi promote the quality of plant material reproduced in containers.
Objective: To evaluate the effect of two commercial mycorrhizal inoculants and one controlled-release fertilizer on the development of Pinus engelmannii Carr. in nursery.
Materials and methods: Two commercial inoculants (fungi native to Mexico [1 mL·plant-1 with 1.05 x 107 spores·mL-1] and exotics [1.5 mL·plant-1 with 6.5 x 106 spores·mL-1]), two doses of a controlled-release fertilizer (11-28-11 NPK [3 and 6 g·L-1]) and a control were evaluated; in total, nine treatments were used. The variables analyzed were: survival, stem height, root collar diameter, wet and dry biomass, ratio of dry biomass of the aerial part/dry biomass of the root part, lignification index, Dickson’s quality index and mycorrhizal colonization.
Results and discussion: Survival (80 to 96 %) was similar between treatments. Eight months after sowing, seedlings showed significant differences (P ≤ 0.05) in morphological variables; combined treatments gave better results. Plants with commercial inoculum of native fungi (1 mL·plant-1 [Amanita rubescens Pers., Amanita sp., Lactarius indigo [Schwein] Fr., Ramaria sp. and Boletus sp.]) and fertilization of 3 g·L-1 had higher Dickson quality index. It was observed that the higher the fertilization dose, the lower the percentage of mycorrhizal colonization.
Conclusion: The combination of ectomycorrhizal inoculum of native fungi and low-dose fertilization showed that both components are complementary in the plant development of P. engelmannii.

Introduction: A factor limiting the development of tree vegetation in urban environments is the condition of the soil.
Objective: To evaluate the effect of the application of carbohydrates (sucrose and glucose) to the soil regarding the growth and vitality of jacaranda trees (Jacaranda mimosifolia D. Don) planted in urban areas.
Materials and methods: Eight carbohydrate treatments and one control (water) were applied. Increase in height and diameter, foliage color, chlorophyll fluorescence, dry root matter, root starch, respiration and soil moisture were evaluated. An analysis of variance and a comparison of means was performed (Tukey, P < 0.05); when the normal distribution of the data was not proved, nonparametric methods were used (Kruskal-Wallis and Wilcoxon rank-sum test).
Results and discussion: The increase in height and diameter, the green color of the foliage and the fluorescence of the chlorophyll showed no significant differences (P > 0.05). Dry root weight and soil respiration were significantly different (P < 0.05) with higher response in the highest carbohydrate treatment (80 g·L-1 glucose with 80 g·L-1 sucrose). There was no effect on the characteristics of the aerial part, possibly due to the short evaluation time (about one year).
Conclusion: The amendment of glucose and sucrose to the soil in urban trees stimulated the root growth of J. mimosifolia.

Introduction: Bibliometric analysis is a quantitative tool for recognizing trends and research gaps in topics of scientific interest.
Objective: To identify progress in scientific production, collaborative networks, research issues and application of models of temperate forest management (MTFM), on a global scale, in relation to management, productivity, carbon storage and nutrient cycling.
Materials and methods: The review focused on the collection of data from the Web of Science Core Collection platform in the period 2005-2019.
Results and discussion: The bibliometric analysis made possible to collect 960 specialized scientific articles on the topic, from journals indexed in Journal Citation Reports (JCR). The institutions with the greatest academic authority in forest management studies were Natural Resources of Canada (NRCan), Institut National de la Recherche Agronomique (INRA) and US Forest Service. MTFM topics focused on forest plantation growth, effects of forest practices on structure, productivity, carbon sequestration and, to a lesser extent, nutrient availability. Mexico showed low collaboration with other institutions and a forest approach in the application of models.
Conclusions: The analysis helped to guide research on MTFM in Mexico. The implementation of models is recommended to achieve forest harvesting based on an integrated understanding of the system and thus provide sustainability.

Introduction: The forest management unit 0807 (UMAFOR 0807) is one of the most productive in timber and water resources provision, but there are no studies of historical hydroclimatic variability and its trends for predictive purposes.
Objective: to generate a precipitation reconstruction through a regional dendrochronological network for the southwest of the state of Chihuahua.
Materials and methods: a network of growth series of five distinctive conifers of UMAFOR 0807 was developed; through Principal Component Analysis the series with the greatest common variance were defined to obtain a representative chronology. The reconstruction model was generated with a series of regional precipitation. The general circulation modes with the greatest impact on rainfall variability and the association of the total ring-width index with the drought indices were analyzed.
Results and discussion: From eight chronologies generated, six showed a common climate response to integrate a regional representative series, which responded to September-July precipitation. The correlation between the total ring-width index and the Palmer Drought Severity Index (PDSI) was 0.68 (P < 0.01) in the June-August period, and 0.71 (P < 0.01) for the Standardized Precipitation Evapotranspiration Index (SPEI) for August of the previous year to June of the current year of growth. The reconstructed precipitation showed significance in spectral peaks of 2.1 and 2.8 years, corresponding to the influence of ENSO (El Niño–Southern Oscillation).
Conclusions: the dendrochronological network composed of various tree species and integrated in a regional chronology allowed to capture the interannual and multiannual variability of the climate.

Introduction: Red cedar (Cedrela odorata L.) is appreciated for its wood, a situation that has caused poor forest management and, therefore, a decrease in its areas of distribution.
Objective: To delimit the current and future potential distribution of C. odorata and to identify suitable seed-producing areas for the conservation of the species in the Yucatan Peninsula.
Materials and methods: Records of the presence of C. odorata were obtained from the Global Biodiversity Information Facility (GBIF), the National Forest and Soil Inventory (INFyS in Spanish) and the book “Árboles tropicales de México”. The modeling was done in MaxEnt using current environmental variables and future (2030) climate change scenarios at 1 km2 spatial resolution. Seventy-five percent of the records were used to train the models and 25 percent to validate them. The variables with the greatest contribution were determined by the jackknife test.
Results and discussion: The estimated current potential distribution of C. odorata was 404917 ha. Climate change simulations predict a reduction (31 to 44.8 %) of the suitable habitat, where the natural protected areas (ANPs) of Calakmul, Los Petenes and Ría Celestún would serve as climate refuges, conserving about 76472 ha. The important variables in the distribution were: vegetation (34.7 %), precipitation of the wettest month (14.6 %), edaphology (8.8 %), average temperature of the coldest quarter (8.6 %) and slope (7 %).
Conclusion: The models allowed the identification of suitable areas with habitat quality of C. odorata. In view of the threats of climate change, the distribution of C. odorata in ANPs would help conservation and restoration programs in situ.

Introduction: Scattered trees from tropical dry forests (TDF) deposit significant amounts of leaf litter into pasture soils.
Objective: To estimate the litterfall production during the dry season by scattered Lysiloma acapulcense (Kunth) Benth. and Vachellia pennatula (Schltdl. & Cham.) Seigler & Ebinger trees in pastures.
Materials and methods: Ten scattered trees of each species were selected from a 10-ha pasture, and litter was collected during the dry season (November to May) and sorted into fractions. Leaf litter biomass, nitrogen (N) and lignin (L) content, and the lignin-nitrogen (L/N) ratio were assessed. Leaf litterfall was modelled over an annual cycle using a double logistic model. Means from all variables were compared between species using a t-test.
Results and discussion: Litter, nitrogen and lignin content were similar between species. However, the L/N ratio was significantly higher (P < 0.0001) in L. acapulcense (32.1) than in V. pennatula (21.3). The leaf litter model showed that the defoliation phase of L. acapulcense lasted 30 days longer than that of V. pennatula.
Conclusion: The quantity and quality of leaf litter that scattered trees deposit in a pasture encourages the adoption of agroforestry systems, including tree species native to TDF

Introduction: Sampling by fixed area plots is the usual practice in forest inventories, despite the considerable time involved. An alternative method of sampling is the angle count or Bitterlich method.
Objective: To evaluate the accuracy and efficiency of the angle sampling method for the determination of dasometric variables in teak (Tectona grandis L. f.) plantations.
Materials and methods: In a three-year teak plantation, 21 circular plots of 500 m2 were established. In each plot, the diameter at breast level, the height and position of each tree, the working times, the number of trees per hectare, the diameter of the average basal area, the total basal area, the average Lorey level and the total volume were determined. Angular sampling was simulated using basal area factors (BAF) of 0.5, 1, 1.5 and 2. The estimates of the variables for each BAF and fixed area plots were compared using ANOVA and the relative efficiency was determined.
Results and discussion: The ANOVA did not detect significant differences (P < 0.05) in the estimation of dasometric variables between sampling types, which demonstrates that the angular method is accurate. The fixed area and shape plot required more working time (P < 0.05). The relative efficiency of the angular method was between 4.5 and 11 times higher than that of fixed area plot. The ideal BAF in young teak plantations was equal to two.
Conclusions: Angular counting is accurate and more efficient for estimating dasometric variables in young teak plantations.

Introduction: Estimating the risk of occurrence of a fire contributes to reducing human, infrastructure and natural resource losses; promoting activities to maintain and restore fire regimes; and optimizing resources for suppression.
Objective: To develop an index of occurrence of forest fires on large areas, called Area at risk of fire (SeR).
Materials and methods: The index corresponds to the area associated with a probability level measured at the right tail of the density distribution of the area affected annually by forest fires. The density distribution was estimated from the history of the area affected (1970-2018) in Mexico by state. The fit was performed by minimizing the Kolmogorov- Smirnov statistic with four models: exponential, gamma, lognormal and Weibull. Two related indicators are proposed: proportion of forest area affected by wildfires (PSeR) and incremental area at risk (ISeR).
Results and discussion: all models showed a statistically significant fit (P < 0.05); the lognormal model performed the best. The SeR discriminates territorial units with the largest area affected by fires; additionally, it efficiently predicts the area to be affected by fires. The PSeR facilitates the comparison of the risk of fire occurrence between territorial units of different sizes, while the ISeR estimates the change in the maximum area affected by fires over a period.
Conclusion: SeR is an extreme event risk index that provides useful information and has a statistically acceptable predictive power.

Introduction: Geomorphological processes, such as flash floods, affect the natural growth of trees. From the dating of disturbances in growth rings, historical events useful for the prevention and mitigation of natural hazards were reconstructed.
Objectives: To determine the dendrogeomorphological potential of Pinus ponderosa Douglas ex C. Lawson to date and reconstruct flash floods in Los Picos de Davis, Coahuila.
Materials and methods: Samples were collected from 19 dead and living trees with evidence of disturbance (impact scars, growth suppression and compression wood). The samples were prepared, dated and analyzed based on dendrogeomorphological techniques. The reconstructed flash floods were related to historical climate information from hurricanes, tropical cyclones and precipitation.
Results and discussion: We were able to date 68 % of the samples with evidence of disturbance; the correlation between growth series was significant (r = 0.403; P < 0.001). The most common anomalies were in the form of scars (72 %), growth suppression (20 %) and compression wood (8 %). Ten flash floods were reconstructed. The causative processes were flash floods, caused by extreme hydrometeorological phenomena, including hurricanes “Alex” in 2010, “Dolly” in 2008 and “Claudette” in 2003. There is synchrony between geomorphological processes and hydrometeorological phenomena.
Conclusions: P. ponderosa ring disturbances are useful to reconstruct the frequency and distribution of geomorphological processes.

Introduction: In Pinus radiata D. Don, one of the most widely planted pines globally, frost damages plantations at the seedling stage.
Objective: To determine differences in growth and tolerance to low temperatures of native populations (Guadalupe and Cedros islands) of P. radiata in greenhouse and outdoors conditions, under different levels of soil moisture.
Materials and methods: Low-temperature tolerance was determined through the damage index (DI) in freezing tests at -12 °C during 4 h. In each environment (greenhouse and outdoors) two soil moisture treatments were defined (irrigation and drought). The DI was evaluated with the method of electrical conductivity in primary needles during winter and spring. The absolute growth rate (AGR) of the terminal shoot was obtained by measuring the total height of the seedlings.
Results and discussion: Average DI of 50 and 64 % were obtained in winter and spring, respectively. In greenhouse, DI was different (P ≤ 0.05) between populations, being higher in Guadalupe (>59 %) than in Cedros (<42 %), both in winter and spring. Outdoors, Cedros (64.1 %) had a higher DI than Guadalupe (36.5 %) only during winter. DI was similar in both favorable soil moisture and drought conditions. The Guadalupe population presented higher AGRs in both environments and moisture conditions.
Conclusion: The population of Guadalupe is more sensitive to low temperatures with greater variation in DI, due to its growth dynamics. Differences between populations are useful in the genetic improvement of the species.