Introduction

The lama-bordo systems (LBS) are built in natural watercourses and favor retention of sediment and runoff moisture for the development of agricultural activity.

Objective

To obtain a model for predicting the volume of soil permanently captured by LBS, based on the morphometric and hydrological characteristics of the micro-watersheds where they have prevailed in the Mixteca Alta of Oaxaca, Mexico

Materials and methods

The study was carried out in 27 sites where morphometric parameters and hydrological indexes were determined to obtain the volume prediction model by multiple linear regression (backward elimination technique).

Results and discussion

The systems studied were found in micro-watersheds under conditions that favor sediment transport: elongated shape, areas smaller than 2 km² with 1st and 2nd order streams, at altitudes above 2 000 m and slopes greater than 10 %. Twelve morphometric parameters and three hydrological indexes characterize these micro-watersheds and explain the physical conditions that allow their establishment, but only four (micro-watershed area, average slope of the mainstream, topographic wetness index and sediment transport index) explain the cumulative sediment volume (R² = 0.85, P < 0.001).

Conclusions

The model evaluated for volume estimation is reliable for application at sites under similar conditions.

Introduction

Floods are a common phenomenon in flat ecosystems with deficiencies in river drainage, impacting the local and regional economy. They can be identified and analyzed by remote sensing.

Objective

The aim of this study was to evaluate the performance of two normalized water indices during periods of maximum and minimum annual precipitation for the identification of flooding in the Salado River Basin, Argentina.

Materials and methods

The years with maximum and minimum annual precipitation in the period 2001-2020 were derived from satellite estimates of monthly precipitation provided by NASA through Google Earth Engine. Floods were identified using Landsat images, applying two normalized water indices (NDWI -Normalized Difference Water Index- and modified NDWI) to evaluate their performance in generating binary images that better represent the reality of the study area.

Results and discussion

Both indices showed good capability in identifying permanent or semi-permanent watercourses and water bodies; however, only the NDWI demonstrated higher effectiveness in identifying flooded areas with shallow depths (5 to 15 cm). The use of the Landsat mid-infrared band (1 566 - 1 651 µm) is less sensitive to water sediment load and can reflect subtle differences in it, providing a greater ability to delineate the water-soil boundary.

Conclusion

The use of NDWI showed a suitable behavior for the identification of flooded areas in very low slope ecosystems

Introduction

The forestry sector faces energy challenges that involve the precise determination of the final energy consumption to achieve improvements.

Objective

To estimate the final energy consumed while processing timber forest resources.

Materials and methods

The Total Final Consumption (TFC) was determined in six companies (statistical units) engaged in primary timber processing in Pueblo Nuevo, Durango. Activity data and significant energy uses (SEUs) for two years were obtained through an energy audit. The data were disaggregated by statistical unit, activity, form and application of energy, and expressed in tons of oil equivalent (toe).

Results and discussion

The energy consumption per statistical unit was estimated at 71.19 toe·yr^-1, releasing 260.14 tCO₂e·yr^-1. SEU was identified in vehicles with diesel engines (75 %). The use of gasoline and electrical energy in machines accounted for 14.2 % and 10.7 %, respectively. Electric motors used up to 98 % of the electrical energy. Logging represented 69 % of the Total Final Consumption (TFC), more than twice compared to sawing. Energy consumption was significantly different between statistical units (Tukey, P < 0.05) for sawing, but not for logging.

Conclusions

Energy consumption for logging was similar among the units studied but was not similar for sawing. An effective energy management program and the integration of wood energy could optimize the consumption pattern.

Introduction

The gall wasp Andricus quercuslaurinus Melika & Pujade-Villar causes the death of Quercus affinis Scheidw. in Acaxochitlán, Hidalgo. The genetic capacity of parents with tolerance to the pest can be conserved by grafting.

Objectives

The aim of this study is to establish the conditions for grafting of Quercus affinis individuals tolerant to A. quercuslaurinus attack.

Materials and methods

Scions of five tolerant and five susceptible phenotypes were collected. Homografts (Q. affinis scions on Q. affinis rootstocks) and heterografts (Q. affinis on Q. rugosa Née) were made with terminal fissure and side-veneer graft. Tests were carried out on five dates and with materials of different ages. Grafting success was evaluated with ANOVA and Tukey\'s test (P = 0.05). Grafting was determined by fitting the Weibull accelerated failure time model.

Results and discussion

Statistical differences (P ≤ 0.05) were found in grafting by phenotype effect. Grafting success rate with scions from tolerant trees was 166 % higher than with scions from susceptible trees. The highest grafting was obtained in homografts (90 %) with scions from young tolerant trees (12 years old) and heterografts (88 %) with scions from adult tolerant trees (35 and 40 years old).

Conclusions

The propagation of Q. affinis individuals tolerant to A. quercuslaurinus attack is possible by homografts (young trees) and heterografts (adult trees) with Q. rugosa rootstocks, preferably in early autumn.

Introduction

Carbon storage studies in arid and semi-arid zones are limited. The use of UAVs (unmanned aerial vehicles) has made it easier to monitor areas of interest, which is difficult with more costly techniques.

Objective

The aim of this study is to develop predictive models, using aerial images, to estimate aboveground carbon biomass (ABCS) in subtropical shrub species of Sonora.

Materials and methods

ABCS of tree species (>2 m in height) was estimated using field-collected metrics and allometric equations. Remote vegetation metrics (camera mounted on UAV) were obtained using both manual methods (digitization) and automated methods (ForestTools algorithm). Non-parametric tests (Wilcoxon) were conducted to determine differences between field metrics and aerial image metrics. These were used to construct predictive models of individual-level ABCS.

Results and discussion

The Wilcoxon test indicated that the maximum crown height estimated in the field and with both approaches is similar (P > 0.05), while crown area and crown volume in situ showed no significant differences (P > 0.05) with the manual approach but shows significant differences with the automated approach (P < 0.05). The predictive models of aboveground carbon biomass (ABCS) with remote approaches were statistically significant (P < 0.001). This suggests that carbon estimation using images can explain the variability of the reference method at the individual level.

Conclusion

Aerial imagery is a viable and practical tool for estimating ABCS of trees and shrubs in arid/semiarid communities.

Introduction

Reforestation and restoration of forest ecosystems are increasingly difficult with climate change.

Objective

Define seed transfer zones for reforestation in the Monarch Butterfly Biosphere Reserve and the ‘Sembrando Vida’ program in the Meseta Purépecha to mitigate climate change.

Materials and methods

Maps were generated to visualize where the ideal climate conditions for reforestation are projected to occur (RCP 4.5 scenario, 2050) at different sites using seedlings collected in delimited areas under a reference climate (1961-1990). A climate zone system was used (based on the temperature of the coldest month and an aridity index) and layers of suitable climatic habitat for Pinus pseudostrobus and Abies religiosa for the reference (1961-1990) and projected (2060 decade) period.

Results and discussion

The areas to be reforested will be warmer in the future, requiring seed from sites, on average, 3 °C warmer. A reduction of approximately 50 % of the area of climatically favorable habitat for P. pseudostrobus and A. religiosa was estimated. This reduction occurs at the lower altitudinal limit called the \'xeric limit’; therefore, it will be necessary to replace them with species adapted to warmer sites.

Conclusions

Moving seed sources from warmer (+3 °C) and drier sites to currently wetter and cooler planting sites is recommended. This provides a useful tool for deciding the seed source under adaptive forest management facing climate change.

Introduction

Drones allow collecting high-spatial resolution images useful for monitoring forest vegetation dynamics in managed forests. There are, however, doubts about the most effective way to use them concerning spatial resolution.

Objective

To identify the optimal spatial resolution of multispectral images captured by drones for mapping land cover types in managed temperate forests in Hidalgo, Mexico.

Materials and methods

Spectral images were preprocessed at spatial resolutions from 0.2 to 2.5 m, at 0.1 m intervals. Pine, oak, other broad-leaved trees, herbs and bare soil cover were classified with the Random Forest algorithm. The effect of spatial resolution on land cover classification was evaluated using the Kruskal-Wallis non-parametric test followed by a Mann-Whitney-Wilcoxon post-hoc comparison (p < 0.05). Classification errors of land cover classes were analyzed graphically.

Results

0.2 m spatial resolution images provided the highest land cover classification accuracy (96 %) but was statistically similar to that of 0.7 m (p = 0.3984). The lowest accuracy (82 %) was obtained with 2.5 m spatial resolution imagery. Omission and commission errors were lower and consistent in classifications with 0.2 to 1.2 m spatial resolution images.

Conclusion

Multispectral images (0.7 m resolution), acquired with a fixed-wing drone, allowed us to classify the land cover/vegetation types and the exact spatial distribution of pine, oak and other hardwood species in a temperate forest under forest management.

Introduction

The Dark Winged Fungus Gnat, Bradysia impatiens Johannsen, is a significant pest in modern forest nurseries in Mexico, as it causes plant mortality. However, studies on adult monitoring are scarce.

Objectives

Determine the most suitable trap for monitoring B. impatiens, characterize its population levels and identify associated organisms, including its natural enemies.

Materials and methods

The attraction effect of B. impatiens to two types of yellow sticky traps (circular and flag paper trap) and a colorless trap was evaluated. After selecting the best trap, the capture of B. impatiens and associated organisms was compared across four forest nurseries to determine the species\' population levels. Capture data were analyzed using generalized linear models with negative binomial regression.

Results and discussion

Flag paper trap was the most efficient for capturing adults. Based on weekly captures, three population levels were subjectively rated: low (<30 adults), medium (30-60 adults), and high (>60 adults). Coenosia attenuata Stein was found as a natural enemy of the pest; however, the capture percentage was low (1.78 %), so the traps do not pose a threat to their populations. Kleidotoma sp., a possible parasitoid of the pest and C. attenuata, was also found.

Conclusions

An integrated pest management plan for B. impatiens is necessary, including flag paper trap and the predator C. attenuata as biological control in nurseries. C. attenuata, a predator of B. impatiens, is recorded for the first time in Tlaxcala.

Introduction

Land use/land cover change (LULCC) alters the quantity and quality of ecosystem services. The economic value of these services is an indicator of change that facilitates conservation, utilization, and restoration activities of ecosystems.

Objective

To analyze the dynamics of land use/land cover (LULC) from 2000 to 2020 and estimate the ecosystem services value (ESV) as an indicator of ecological degradation in the Copalita River watershed in Oaxaca.

Materials and methods

Landsat 7 and 8 images captured during the years 2000 and 2020, respectively, were used. Six types of LULC were identified and classified in the watershed, and an intensity analysis was performed. Based on the economic values of biomes previously published, the values of LULC and ecosystem service functions in the watershed were estimated.

Results and discussion

There is an increase in forest cover (13.23 %), low-cover lands (494.41 %), construction (75.35 %), and wetlands (38.34 %), and a decrease in the area of rainforest (-48.02 %) and water bodies (-32.71 %). LULCC dynamics caused a 2.21 % reduction in the ESV of the watershed. The value of provisioning services increased (49.10 %), while regulation (-12.39 %), cultural (-4.77 %), and support (-3.89 %) values decreased.

Conclusions

The reduction in the economic value of ecosystem service functions is caused by the effects of LULCC on the decrease in rainforest and water bodies in the watershed.

Introduction

The degradation of forest ecosystems has driven the adoption of mechanisms for their conservation and sustainable use.

Objective

To identify the state of knowledge regarding oak forests in Mexico associated with public policy mechanisms for conservation and use: Natural Protected Areas (NPA), Payment for Ecosystem Services (PES), and Community Forest Management (CFM).

Materials and methods

The methodological framework of search, evaluation, synthesis, and analysis was used. Information was obtained from Scopus, Scielo, and Redalyc platforms. The found documents were subjected to an inclusion and exclusion process based on criteria of temporality and primary sources.

Results and discussion

A total of 662 studies were identified, of which 37 published between 2000 and 2022 were analyzed. Of these, 17 are related to Community Forest Management (CFM), examining characteristics of forest communities and socio-ecological effects; 13 addressed topics related to NPA, focusing on the conservation biology of flora and fauna; and two contributions centered on PES, highlighting analyses and evaluations of socio-environmental effects. Lastly, five studies involved two or three of the mentioned instruments.

Conclusions

The analysis of oak forests concerning public policies for conservation and sustainable use has significantly increased. The studies indicate that such policies contribute to reducing the risk of adverse changes in these forests. Due to the ecological, social, and economic importance of oak forests, it is recommended to understand them through socio-ecological systems and transdisciplinary approaches.