Introduction: Podocarpaceae is the only family of native conifers in the tropical Andes. In Colombia, Retrophyllum rospigliosii (Pilg.) C. N. Page is significant due to its wide geographic distribution; however, no biomass and carbon equations exist for this species.
Objective: To estimate the carbon capture potential of mature R. rospigliosii plantations established for restoration purposes.
Materials and methods: Thirty trees were selected based on diameter distribution of trees to evaluate stem volume and aboveground biomass, and 12 trees were analyzed to assess belowground biomass and carbon content in tree components (stem, branches, leaves, and roots). The variables—volume, biomass, and carbon—were correlated with diameter at breast height and total height using Husch and Spurr models.
Results and discussion: The adjusted models achieved R² values greater than 94 %. The stem provided the highest percentage of biomass, followed by coarse roots, branches, fine roots, and leaves. Carbon content in R. rospigliosii components ranged between 41.08 % and 49.97 %. Over a 20-year period, high-density monoculture  plantations (1666 trees·ha^-1) of R. rospigliosii were estimated to produce 316.26 ± 187.26 Mg∙ha-1 of biomass and sequester 156.08 ± 92.80 Mg· Mg∙ha^-1 of carbon.
Conclusion: Biomass and carbon sequestration of R. rospigliosii in plantations were relatively low compared to individuals in natural forests. The models indicate the low productivity of this species in terms of carbon sequestration.

Introduction

Quintana Roo is the only state in the Yucatán Peninsula where the limno-terrestrial tardigrade fauna has been documented; however, the records have been limited to generic reports.
Objective

To provide an updated checklist of limno-terrestrial tardigrades for Quintana Roo and to explore the spatiotemporal variation of these animals in two rural environments.
Materials and methods

A taxonomic review was conducted on tardigrades collected between 2016 and 2018. Moreover, during two sampling campaigns in 2018, specimens were collected from the moss Aulacopilum sp. and the lichen Parmotrema sp. in a citrus plantation and an evergreen forest fragment. Data were compared using the student’s t test (P < 0.05).
Results and discussion

Kristenseniscus kofordi, Milnesium sp. 1, Milnesium cf. cassandrae, Macrobiotus alvaroi, Macrobiotus cf. polyopus, Macrobiotus cf. ocotensis, Macrobiotus sp. 1, Macrobiotus cf. semmelweisi, Minibiotus cf. intermedius, Paramacrobiotus cf. savai, Mesobiotus cf. pseudopatiens and Ramazzottius cf. baumanni were recorded. The addition of these taxa, along with previous records of Echiniscus sp. and Doryphoribius chetumalensis, increases the number of limno-terrestrial tardigrade species in Quintana Roo to 14, also the coastal mangrove forest is added to the list of environments in the entity. The highest species richness and Shannon-Wiener diversity were observed in the citrus plantation.
Conclusions

The updated checklist of limno-terrestrial tardigrades in Quintana Roo comprises 14 species. Diversity was higher in the citrus plantation, suggesting that tardigrades adapt well to anthropogenic environments.

Introduction

Due to practicality and reliability, the indicators ‘crown condition’ and ‘tree damage’ have been used to assess the health condition of urban trees.

Objective

To determine the health condition of Ficus microcarpa L. f. trees using the indicators ‘crown condition’ and ‘tree damage’ in Cuernavaca, Morelos.

Materials and methods

A total of 387 F. microcarpa trees were assessed for the following variables: live crown ratio (LCr), crown density, crown dieback, foliage transparency, and the presence of biotic, abiotic, and anthropogenic damage.

Results and  discussion

In Cuernavaca, Ficus microcarpa trees  have  heights  ranging  from  3  to  5  m and diameters between 20 and 40 cm,  classified  as  young  to  mature  trees.  Health  condition  of  trees was considered good, with an average LCR of 70 %, crown diameter of 65 %, and dieback of 5 %, except for foliage transparency, which, at 35 %, classified the trees into a moderate health category. The most frequent tree damage was reduced living space (55.21 %) and topiary (18 %). Only 32 dead trees (8.26 %) were recorded.

Conclusion

Crown condition and tree damage indicators were used to determine F. macrocarpa health. Foliage transparency is an early stress indicator that can be attributed to damage agents, mostly of abiotic and anthropogenic origin.

Introduction

Understanding the optimal conditions for acorn storage is  essential  for  their subsequent use in nursery plant production.

Objectives

To evaluate the effect of storage media on germination of Quercus durifolia acorns.

Materials and Methods

The following storage media were evaluated for acorns: 1) fresh pine sawdust, 2) perlite, 3) peat  moss,  4)  vermiculite,  and  5)  control  (without  substrate).  Transparent 250 mL plastic containers were used as storage containers. The acorns were placed in containers mixed with the storage medium and stored at 5 °C for six months. The variables analyzed were cumulative germination percentage and germination speed index.

Results and discussion

From the first month, the fresh sawdust treatment had the lowest percentage of rotten seeds (30 %) and the highest germination rate (76 %), which decreased to 58 % by the end of the storage period. In contrast, acorns stored in perlite, vermiculite, and without substrate showed no germination after six months. For peat moss, germination values ranged from 31 to 20.3 %; seeds stored in this medium, along with those in the control showed a drastic reduction in the germination speed index (8.6 and 13.0, respectively).

Conclusions

Acorns stored in fresh sawdust at 5  °C  had  the  highest  germination  rate.  This study provides a cost-effective alternative to prolong acorn viability for nursery plant production, reforestation, and restoration with this species.

Introduction

Brosimum alicastrum Swartz, a tree species with potential for both animal and human consumption, grows naturally with no silvicultural management.

Objective

To determine which asexual propagation technique (air layering or grafting) produces  the  best- quality nursery individuals, to evaluate its viability in a plantation.

Materials and methods

Completely randomized experimental designs were developed to evaluate air layering (factorial arrangement: substrate [coconut fiber, peat moss, and forest soil] and rooting hormone [Radix 10000® and no rooting hormone]) and grafting techniques (budding, side veneer, whip and tongue, and crown grafting). Subsequently, 10 individuals from each air layering and grafting treatment were randomly selected for plantation establishment. Survival and tree-measurement characteristics were evaluated for each treatment.

Results and discussion

The growth of air-layered clones was more significant with peat moss and forest soil substrates (P = 0.05); the rooting hormone had no significant effect. Bud grafting was not viable; success rates ranged from 65 % to 80 % with the other techniques. Some air layering and grafting treatments performed well in the nursery, but their individuals did not survive after transplanting them to the field. Air-layered clones using forest soil as a substrate showed the highest growth rates, as well as the greatest percentages of flowering (70 %) and fruit production (50 %) in the plantation.

Conclusions

Air-layered clones using forest soil and grafts using whip and tongue or crown grafting had the best characteristics in the plantation. The propagation method should be selected based on the intended final use of the germplasm (seed, leaf, or wood).

Introduction

Cacao is a perennial crop of economic importance in  southeastern  Mexico,  where  the black stink bug (Antiteuchus tripterus Fabricius) has been reported as a pest. Control of this insect through entomopathogenic fungi represents a sustainable alternative.

Objective

To characterize and select native isolates of Metarhizium brunneum Petch with biocontrol potential against the black stink bug (A. tripterus) in Tabasco, Mexico.

Materials and methods

Five fungal strains were isolated and characterized based on morphological, molecular, physiological, and pathogenic traits. Phylogenetic analysis was conducted using IQ-TREE v2. Mycelial growth (MG), conidial germination (CG), and conidial production (CP) were evaluated at 25, 30, and 35 °C. These variables, along with pathogenicity, were analyzed using ANOVA and Tukey’s HSD test (P < 0.05). The time required to reach 50 % (GT50) and 90 % (GT90) conidial germination was estimated using Probit analysis.

Results and discussion

All isolates were identified as Metarhizium brunneum. Significant differences (P < 0.05) were observed in MG, CP, and pathogenicity. The most favorable temperature range for the fungus was 25 to

30 °C. GT50 ranged from 7.8 to 21.9 h, and GT90 from 9.5 to 27.7 h. Pathogenic effectiveness ranged from 72 to 96 %. Isolates TCCH5 and TCCH8 showed the greatest potential as biological control agents against A. tripterus.

Conclusions

This study reports, for the first time, the pathogenicity of M. brunneum against A. tripterus. Field studies are necessary to evaluate the most promising isolates under natural conditions.

Introduction

The study of tree-rings has achieved great relevance due to its increasing application to address sciences such as Climatology, Ecology, Geomorphology, among others.

Objective

To carry out a bibliometric analysis of the dendrochronological studies developed in Mexico, providing an overview of research trends and identifying areas of opportunity for future development of this science.

Materials and methods

Articles published between 2000 and 2023 were searched in Web of Science, Scopus, Redalyc, and Scielo. The data was analyzed using VOSviewer software.

Results and discussion

A total of 229 articles were found, involving 76 tree species in 25 states; Sinaloa, Tabasco, Campeche, Quintana Roo, Aguascalientes, Nayarit, and Guerrero lack dendrochronological research. Pinus hartwegii, Pseudotsuga menziesii, and Abies religiosa are the most explored species. Over the past 13 years, publications have increased exponentially (R² = 0.837); the majority focus on dendroclimatology (52%), while dendrovolcanology, dendroarchaeology, and dendrohydrology have been minimally explored. Mexican journals published only 26 % of the articles, and the main collaboration networks include the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, the Universidad Nacional Autónoma de México and the
Universidad Juárez del Estado de Durango.

Conclusions

Few studies were identified on tropical and broadleaf species, despite their dendrochronological potential, and there are seven states where no research has been conducted on this topic. The information generated provides opportunities for developing studies on growth rate analysis, hydroclimatic reconstructions, and ecological research for species conservation.

Introduction
Taper equations are useful tools in forest management, and their application can be extended to species in arid or semi-arid ecosystems.

Objective
To develop a compatible system of equations for estimating the volume of individual trees of Juniperus coahuilensis (Martínez) Gaussen ex R. P. Adams in the semi-desert region of Durango.

Materials and methods
A total of 153 trees were destructively sampled. Iterated seemingly unrelated regression (ITSUR) was used to simultaneously fit the system, ensuring minimum error and compatibility among the equations. Heteroscedasticity and autocorrelation in the hierarchical data was corrected using weighted regression and a continuous second-order autoregressive model, respectively.

Results
The system of equations is the first developed for J. coahuilensis in Mexico and includes a taper function, a merchantable volume equation, and equations for stem volume, coarse branch volume, and total volume. The equations explained 98 % of the observed variability in merchantable volume, 86 % in
stem volume, and more than 45 % of the variability in branch volume.

Conclusions
The use of the compatible system of equations developed will be useful for the management of J. coahuilensis in arid and semi-arid ecosystems and will reduce errors in total tree volume estimates.

Introduction
Due to significant population growth, the San Diego Tlailotlacan Drinking Water System, located in the municipality of Texcoco, Estado de México, faces challenges in maintaining its water distribution network, particularly in improving the frequency and quality of the supply.

Objective
To estimate users’ willingness to pay (WTP) for the improvement of the hydraulic network to enhance the quality and reliability of the drinking water service.

Materials and methods
The Contingent Valuation Method (CVM) was applied using a dichotomous choice referendum format to estimate WTP for a hypothetical improvement in the drinking water service. WTP was calculated using both parametric and non-parametric estimation methods.

Results
The mean WTP was 37.29 MXN using the parametric method and 31.25 MXN using nonparametric methods. The confidence intervals for both estimates overlapped. The most significant variables were the amount to be paid, economic dependents, education level and economic fee discount.
Users receiving fee discount (discounts on water bill) demonstrated a lower willingness to pay for service improvements. 

Conclusions. The total annual value for the improvement was estimated at 1 210 880.00 MXN for the hydraulic network improvement. It is recommended to use the non-parametric estimation method as a complement to the parametric method to assess the consistency of the latter, especially when facing variations in model specification.