Revista Mexicana de Ciencias Forestales Vol. 15 (85)

Septiembre - Octubre (2024)

Fecha de recepción/Reception date: 6 de marzo de 2024.

Fecha de aceptación/Acceptance date: 28 de junio de 2024.

^{_______________________________}

¹Universidad Autónoma de Chihuahua, Facultad de Ciencias Agrícolas y Forestales. México.

²Universidad Autónoma de Nuevo León, Facultad de Ciencias Forestales. México.

*Autor por correspondencia; correo-e: rnarvaez@uach.mx

*Corresponding autor; e-mail: rnarvaez@uach.mx

Abstract

Pseudotsuga menziesii is “subject to special protection”. In Mexico due to its restricted distribution in small and isolated populations in the Sierra Madre Occidental and Oriental, and some localities in Central Mexico. Currently, few ecological studies allow implementation strategies for its conservation. Therefore, the objective of the present study was to determine the distribution, structure and diversity of mixed forests with the presence of this species in Chihuahua. Using the Land Use and Vegetation Chart of Chihuahua State scale 1:50 000, geographical coordinates of the State Forest and Soil Inventory (Iefys) 2009-2014 and records of various locations, the map of its distribution in the state was prepared. With the information on the tree stratum of 11 Iefys locations, the Importance Value Index (IVI) and diversity were determined with the Shannon-Wiener index (H') and Pielou's evenness index (J'); Hutcheson's t-test was used to obtain significant differences in H' and true diversity for the magnitude of their differences. 21 species were recorded, of which the most important are Pinus durangensis, Pinus strobiformis, Pseudotsuga menziesii, Pinus arizonica and Quercus sideroxyla. The species of interest is distributed in 23 municipalities of Chihuahua, and covers an approximate area of 17 000 ha. The values of H' (<2.00) and J' (>0.70) indicate low diversity and high evenness of their abundances. The present study will contribute to the State Strategy for the Conservation and Sustainable Use of the Biodiversity of species at risk.

Key words: Oregon pine, biological conservation, temperate ecosystems, Importance Value Index, Pseudotsuga menziesii (Mirb.) Franco, floristic richness. 

Resumen

En México, Pseudotsuga menziesii está “sujeta a protección especial” por su distribución restringida en poblaciones pequeñas y aisladas en las Sierras Madre Occidental y Oriental, y algunas localidades del Centro de México. Actualmente, son escasos los estudios ecológicos que permitan implementar estrategias para su conservación. Por lo anterior, el objetivo del presente estudio fue determinar la distribución, estructura y diversidad de bosques mixtos con presencia de esta especie en Chihuahua. Mediante la Carta de Uso de Suelo y Vegetación de Chihuahua escala 1:50 000, coordenadas geográficas del Inventario Estatal Forestal y de Suelos (Iefys) 2009-2014 y registros de diversas localidades, se elaboró el mapa de su distribución en el estado. Con la información del estrato arbóreo de 11 localidades del Iefys se determinó el Índice de Valor de Importancia (IVI) y la diversidad con el Índice de Shannon-Wiener (H’) y de Equidad de Pielou (J’); la prueba de t de Hutcheson se utilizó para obtener diferencias significativas de H’ y la diversidad verdadera para la magnitud de sus diferencias. Se registraron 21 especies, las de mayor importancia fueron Pinus durangensis, Pinus strobiformis, Pseudotsuga menziesii, Pinus arizonica y Quercus sideroxyla. La especie de interésse distribuye en 23 municipios de Chihuahua, y comprende una superficie aproximada de 17 000 ha. Los valores de H’ (<2.00) y J’ (>0.70) indican una baja diversidad y una alta equidad de sus abundancias. El presente estudio contribuirá a la Estrategia Estatal para la Conservación y Uso Sustentable de la Biodiversidad de especies en riesgo.

Palabras clave: Ayarín, conservación biológica, ecosistemas templados, Índice de Valor de Importancia, Pseudotsuga menziesii (Mirb.) Franco, riqueza florística.

Introduction

The state of Chihuahua is the largest in the Mexican Republic, it has a great diversity of species and ecosystems, and one of the most representative associations is its temperate forests, with an area of 7.4 million hectares (Inegi, 2021). They are distributed in the Northern part of the Sierra Madre Occidental (SMO), which has been recognized as a megacenter of diversity (Felger et al., 1997). Numerous endemic species survive in these ecosystems, or within the NOM-059-SEMARNAT-2010 (Royo-Márquez et al., 2014), such as Pseudotsuga menziesii (Mirb.) Franco, a species “subject to special protection” that lives in small discontinuous populations in the high parts of the mountains (Rzedowski, 2006; Mápula-Larreta et al., 2007).

To date, there are few works in Mexico with an ecological approach to species within any risk category (Pompa-García et al., 2017), such as Pseudotsuga menziesii, which only brings together some works on diversity and structure in the Sierra Madre Occidental (Moreno et al., 2018; García et al., 2020; García-García et al., 2021; Molina-Marchan et al., 2024a). Ventura et al. (2010) point out that more research is required on the distribution of these populations and their current status. Likewise, Martínez-Sifuentes et al. (2022) reaffirm the importance of the conservation of these habitats in the face of the effects of climate change and anthropogenic activities, and highlight the development of preservation measures based on their distribution, density and conditions in which they develop. These type of studies contribute to know the state of forests and their response to natural and anthropogenic impacts, in order to monitor and execute management and conservation plans (Spellerberg, 1991).

Therefore, the objective of this research was to determine the distribution, structure and diversity of the tree layer of the Pseudotsuga menziesii forests in the state of Chihuahua, in order to contribute to the State Strategy for the Conservation and Sustainable Use of the Biodiversity of the National Commission for Knowledge and Use of Biodiversity (Conabio) through strategic axes 1, 4 and 7 that correspond to scientific knowledge and information management for the protection, conservation and attention to threats to biodiversity (Cruz et al., 2015).

Materials and Methods

Study area

Pseudotsuga forests on a national scale cover 57 000 ha distributed in the states of Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Nuevo León, Oaxaca, Puebla, Querétaro, Sonora, Tamaulipas, Tlaxcala, Veracruz and Zacatecas (Figure 1) (Molina-Marchan et al., 2024b). According to García (2004) climate classification, the areas where most populations thrive are temperate sub-humid, with an average annual temperature between 10 and 14 °C and an average annual precipitation greater than 600 mm.

Source: Molina-Marchan et al. (2024b).

Figure 1. Modified map of the distribution of Pseudotsuga menziesii (Mirb.) Franco in Mexico.

In the SMO in Chihuahua, Pseudotsuga Carrière stands are concentrated at altitudes of 2 400 to 3 200 m, in North-facing exposures and moderate to steep slopes ranging from 15 to 72 %, conditions that are present in other regions of the country (Encina-Domínguez et al., 2008; Ventura et al., 2010).

The soils are of the Feozem, Regosol and Litosol type (INEGI, 2014), with depths between 10 and 60 cm, which indicates that they are low and medium depth soils (Conafor, 2014).

Information from the localities from the State Forest and Soil Inventory of the state of Chihuahua 2009-2014 (Conafor, 2014) was used, where each one is made up of four circular sites of 400 m² with the shape of an inverted Y in which the gender and species of all individuals with a normal diameter greater than or equal to 7.5 cm at a height of 1.30 m. Information was available from 62 localities with the presence of Pseudotsuga menziesii (Figure 2), and based on the analysis of the data, those that have an Importance Value Index greater than 5 % of the species were selected (Table 1).

Chihuahua = State of Chihuahua.

Figure 2. Geographic location of the 11 analyzed localities of Pseudotsuga menziesii (Mirb.) Franco.

Table 1. Description of the studied localities of Pseudotsuga menziesii (Mirb.) Franco in the state of Chihuahua.

P = Pinus; Q = Quercus; Ps = Pseudotsuga.

Data analysis

Distribution

The area and distribution of Pseudotsuga menziesii in the state was estimated using the database of the Land Use and Vegetation Chart Scale 1:50 000 (Stock Informático, 2013), which favors greater accuracy for research studies and natural resources management (Stock Informático, 2013) and the records with coordinates of the State Forest and Soil Inventory of Chihuahua (Conafor, 2014) through the QGIS 3.30.2 program (QGIS Development Team, 2023). The localities registered by various authors were also considered (Villanueva et al., 2000; Vargas-Hernández et al., 2003; Cruz-Nicolás et al., 2008; Sánchez et al., 2012; Cibrián et al., 2014; Conanp, 2017; García et al., 2020).

Horizontal structure

The Importance Value Index (IVI) considers the absolute and relative values of abundance, dominance and frequency (Equation 1), it is a quantitative parameter of the horizontal structure and indicates the ecological weight of the species present in a community (Lozada, 2010).

Where:

IVI = Importance Value Index

Ar = Relative abundance

Dr = Relative dominance (basimetric area)

Fr = Relative frequency

Diversity indexes

Diversity was calculated using the Shannon-Wiener index (H') which considers the abundance and richness of species. The more taxa the community and the more equitable has their abundances, the greater their diversity will be (Moreno, 2001). With the Pielou index (J') the evenness between the abundances of the species was obtained, whose values vary between zero and one, and the latter represents maximum evenness (Magurran, 2004).

To determine if there is a significant difference between the communities studied, paired comparisons were made through Hutcheson's t-test (p≤0.05) with the following Equation (Hutcheson, 1970).

Where:

t = Hutcheson's t test

H’1 = Diversity of sample 1

H’2 = Diversity of sample 2

varH’1 = Variance of the diversity obtained for the sample 1

varH’2 = Variance of the diversity obtained for the sample 2

g. l. = Degrees of freedom needed to calculate the value of t

The magnitude of significant differences in diversity was established with the true diversity of order 1 (^qD) (Jost, 2006) as follows: when community A (CA) has greater diversity than community B (CB), the  ratio reflects the times that CA is more diverse than CB (Moreno et al., 2011). The diversity indices were carried out in the PAST statistical program version 4.16 (Hammer et al., 2001).

Results and Discussion

Distribution

The results obtained from the analysis of the Land Use and Vegetation Cartography of the State of Chihuahua (Stock Informático, 2013) indicate that Pseudotsuga menziesii forests occupy an area of 16 276.9 ha distributed in 14 municipalities. However, the State Forest and Soil Inventory 2009-2014 recorded the presence of this species in 9 more municipalities (Figure 3). Therefore, it is estimated that the surface of these forests is around 17 000 ha, which are distributed throughout the SMO from the Southern part in the Cerro Mohinora Protected Natural Area (PNA) in Guadalupe y Calvo, to the North in the Janos PNA.

Figure 3. Area of Pseudotsuga menziesii (Mirb.) Franco by municipality in the state of Chihuahua. 

Of the 23 municipalities where these communities are located, the most important are Guadalupe y Calvo, Guerrero and Bocoyna with 9 497.4 ha, 1 306.5 ha and 1 300.7 ha, respectively (Figure 3). The largest area was recorded in the Guadalupe y Calvo municipality, possibly related to biophysical conditions favorable for its development, such as the average annual precipitation greater than 1 000 mm, the variability of reliefs, cold temperatures, fertile soils and altitudes between 2 200 and 3 200 m (Rzedowski, 2006; Guerra et al., 2012; Moreno et al., 2018; García-García et al., 2024); furthermore, in this area the Cerro Mohinora PNA is located, which is the highest part of the entity. These fir forests in Guadalupe y Calvo form an important biological corridor with the Guanaceví municipality, state of Durango (Molina-Marchan et al., 2024a).

When this species is dominant or co-dominant in Chihuahua, its population density varies between 125 to 155 trees ha^-1 (Conafor, 2014; García et al., 2020), lower values than those reported by Domínguez-Calleros et al. (2014); if it occurs as a secondary species in pine-oak and oak-pine forests, its density accumulates between 30 and 70 trees ha^-1, which coincides with Ventura et al. (2010). Picea martinezii T. F. Patt. records similar figures as a dominant and secondary species with densities of 155 and 52 trees ha^-1, respectively (González et al., 2018).

It should be noted that the distribution of species changes over time, since they are strongly influenced by environmental conditions and anthropogenic activities, which can put the existence of some taxa at risk and favor the permanence and distribution areas of others (Conabio, 2023). An example of this is the forecasts of Martínez-Sifuentes et al. (2022) who point out that the potential distribution areas of Pseudotsuga under different climate scenarios will be reduced by more than 50 % by 2040. To this it should be added the fact that these areas in Mexico are currently affected by land use change, fires and clandestine logging (Mápula-Larreta et al., 2007; Velasco-García et al., 2007). In addition to the above, in Chihuahua and other Northern entities, the Dendroctonus pseudotsugae Hopkins pest has been detected, which mainly damages mature forests of this conifer (Sánchez et al., 2012).

Several species included in NOM-059-SEMARNAT-2010 do not develop in an PNA as mentioned by Luna-Vega et al. (2010); or their representation is scarce, such as the Douglas fir forests that in Chihuahua only comprise 2 928.95 ha (18 %) within an PNA (Table 2).

Table 2. Area of Pseudotsuga menziesii (Mirb.) Franco in Protected Natural Areas of Chihuahua.

Therefore, it is considered of great relevance that with the elements provided by this work, more surface area of these communities is included within an PNA and strategies are implemented to monitor the effect of climate change and anthropogenic activities on current populations for the conservation of these High Conservation Value forests.

Horizontal structure

In the present study, 6 families, 7 genera and 18 species were recorded. The Pinaceae and Fagaceae families were the most important, both with seven species, which together amount to 77.77 % of the total taxa. Pseudotsuga communities bring together a floristic richness of between 3 and 11 species; the most outstanding localities were Basogachi, P. P. Álamo Mocho and Chinatú with 11, 10 and 9 taxa, respectively, similar numbers to those of Domínguez (2004) and González (2019). In addition to the species recorded in this study, others that share the same habitat are: Picea chihuahuana Martínez and Abies durangensis Martínez (García et al., 2020), in the PNA of the Cotorra Serrana Occidental Sanctuary in Madera; in addition to Pseudotsuga menziesii, the main species that make up this community are Abies concolor (Gordon & Glend.) Lindl. ex Hildebr., Pinus strobiformis Engelm., Populus tremuloides Michx., Pinus arizonica Engelm. and Quercus sideroxyla Bonpl. (Conanp, 2023; Molina-Marchan et al., 2024a). The state's Northernmost town of Pseudotsuga is located on Janos in a “sky island”; it is considered an ancient forest and has the greatest floristic richness with 16 species (Cortés et al., 2012).

The IVI of Pseudotsuga menziesii in the studied localities varied between 6 and 41 % (Figure 4), values closely related to natural and anthropogenic disturbances, the succession stage and environmental conditions such as latitude, altitude, precipitation and exposure (Stirling and Wilsey, 2001; Asquith, 2002). In Chihuahua the highest IVI values for this species occur in the Madera PNA with 42 % (Molina-Marchan et al., 2024a); and in the forests of the Cerro Mohinora PNA, from 2 600 m onwards Abies Mill. and Pseudotsuga concentrate 62 to 74 % of the relative abundances (García-García et al., 2024), these results are similar to those reported by Guerra et al. (2012) and González (2019) and possibly the greater presence of Abies and Pseudotsuga in these localities is due to the boreal origin of these genera that find their most favorable environmental conditions for their development in the high parts of the mountains with low temperatures, high humidity and slopes with orientations North (Rzedowski, 2006).

Figure 4. Importance Value Index (IVI) in the studied localities of Pseudotsuga menziesii (Mirb.) Franco.

According to Criterion 1 of the Forest Stewardship Council (Brown et al., 2013), Pseudotsuga forests are considered Areas of High Conservation Value because it cohabits with endemic species such as Quercus fulva Liebm., Quercus obtusata Bonpl., Pinus durangensis Martínez, Pinus lumholtzii B. L. Rob. & Fernald and Quercus sideroxyla, and in NOM-059-SEMARNAT-2010 as Pseudotsuga menziesii, Pinus strobiformis, Picea chihuahuana and Abies concolor.

Pinus strobiformis, P. durangensis, Pseudotsuga menziesii, Quercus sideroxyla and Pinus arizonica were the taxa with the greatest ecological weight within the forests analyzed. Pinus strobiformis frequently coexists in Douglas fir communities, because they share similar environmental requirements in the high, humid parts of the mountains (González et al., 2006); similar results have been recorded by García and González (2003).

Diversity

Based on the Shannon-Wiener index (H'), it was obtained that the diversity of the tree layer of the Pseudotsuga communities is low since the range of values for H' were from 0.78 to 2.04; these results are similar to those reported by Encina-Domínguez et al. (2008), González (2019) and García et al. (2020) for these communities, and coincide with those of Méndez et al. (2018) and Graciano-Ávila et al. (2020) for temperate mixed forests of Mexico. The low diversity of the tree layer in these ecosystems is possibly because they are located in the highest altitudinal gradients of the mountains and, according to Boyle (1996) and Hemp (2005), there is a negative relationship between altitude and diversity of tree species. Challenger and Soberón (2008) and McCain and Grytnes (2010) document that in forests at higher elevations there is a decrease in temperature that generates adverse conditions and only allows the dominance of a small number of taxa. Regarding the Pielou index, the results show that the evenness of their relative abundances is high from 0.71 to 0.97 (Table 3).

Table 3. Diversity indexes and Hutcheson’s t test in Pseudotsuga menziesii (Mirb.) Franco localities.

Different letters indicate significant difference based on Hutcheson's t test (p≤0.05).

In general, the IVI and the high evenness of the relative abundances of the species that make up these communities show that there is no defined dominance of one or several species, which suggests a more efficient distribution of resources (Guzmán, 2009), through niche differentiation, which increases ecosystem productivity and functionality (Harrison et al., 2019).

The forests studied show significant differences in diversity according to the t test (Hutcheson) (Table 3). P. P. Álamo Mocho with H' of 2.04 was the one with the highest value due to its high species richness and high evenness in its abundances. The analysis of true diversity indicates that this locality with 7.6 effective species is 1.17 and 3.51 times more diverse than San Julián and Rio El Nido, which occupied the second and last place in diversity, respectively. Forests with higher indices are more heterogeneous and have a greater complexity of ecological interactions, which favors the stability and resilience of the ecosystem. On the other hand, those localities with a low diversity of species are the most susceptible to effects, such as pests and diseases (Thompson, 2011; Keesing and Ostfeld, 2024); likewise, a poor use of light or soil resources is generated, which establishes a lower diversity of niches (Huuskonen et al., 2021).

Regarding regeneration, approximately 50 % of the localities did not present repopulation of P. menziesii, which is similar to what was described by Velasco-García et al. (2007) and Ventura et al. (2010), due to inbreeding and low germination rate (Cruz-Nicolás et al., 2008); it may also be due to cone and seed pests, interspecific competition, and ecological site conditions.

Current forestry must have a comprehensive approach that includes ecological criteria such as IVI, biomass and species diversity. Likewise, conservation must be a main component of management in order to maintain the functional and structural relationships of the ecosystem, as well as adequate repopulation of the species (Vargas, 2013; Jardel, 2015). The above will allow more stable and resilient ecosystems in the face of disturbance events and climate change.

Conclusions

Chihuahua is one of the states in the country with the largest extension of Pseudotsuga menziesii forests, which are currently under special protection and coexist with other species in some risk categories, according to NOM-059-SEMARNAT-2010. These communities have a low tree diversity that is common in the high and cold parts of the mountains, and their structure has a high evenness in their abundances. Due to their specific ecological requirements, these communities are susceptible to climate change and it is expected that in a period of 20 to 30 years their distribution areas will be drastically reduced. Other factors that are affecting their populations are anthropogenic activities and the Dendroctonus pseudotsugae pest. For these reasons, it is important to monitor the sites of the National Forest and Soil Inventory, and to establish permanent research sites, to evaluate the dynamics and resilience of these communities over time. The inclusion of more surface area of these forests within PNAs is recommended, as well as the implementation of demographic or ecological studies such as this contribution, which allow the implementation of better strategies for conserving these Areas of High Conservation Value.

Acknowledgments

The authors thank the National Forest Commission (Conafor) for providing the database of the State Forestry and Soil Inventory of the state of Chihuahua. As well as the various reviewers who, through their comments, allowed us to improve the quality of the manuscript.

Conflict of interests

The authors have no conflict of interest.

Contribution by author

Emanuel Molina Marchan: preparation of the manuscript, data analysis, and preparation of cartography; Raúl Narváez Flores: review and preparation of the manuscript, support in data analysis and application of corrections; Jesús Miguel Olivas García: review and application of corrections; Javier Hernández Salas: review and support in data analysis; Aldo Saúl Mojica Guerrero: analysis of the Iefys database.

References

Asquith, N. M. 2002. La dinámica del bosque y la diversidad arbórea. In: Guariguata, M. R. y G. H. Kattan (Edits.). Ecología y conservación de bosques neotropicales. Libro Universitario Regional. Cartago, C, Costa Rica. pp. 377-406.

Boyle, B. L. 1996. Changes on altitudinal and latitudinal gradients in neotropical montane forests. Ph. D. Thesis. Washington University. St. Louis, MO, United States of America. 275 p.

Brown, E., N. Dudley, A. Lindhe, D. R. Muhtaman, C. Stewart y T. Synnott (Edits.). 2013. Guía genérica para la identificación de altos valores de conservación. Red de Recursos de AVC (HCVRN). Estocolmo, STO, Suiza. 65 p. https://www.proforest.net/fileadmin/uploads/proforest/Documents/Publications/guia-generica-para-la-identificacion-de-altos-valores-de-conservacion.pdf. (15 de junio de 2024).

Challenger, A. y J. Soberón. 2008. Los ecosistemas terrestres. In: Sarukhán, J. (Coord.). Capital natural de México. Vol. I: Conocimiento Actual de la Biodiversidad. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio). Tlalpan, D. F., México. pp. 87-108.

Cibrián T., D., O. A. Pérez-Vera, S. E. García D., V. D. Cibrián L., J. Cruz J. y G. Hernández A. 2014. Tizón suizo (Phaeocryptopus gaeumannii (Rhode) Petrak) en Pseudotsuga menziesii var. glauca (Beissn.) Mayr. Revista Mexicana de Ciencias Forestales 5(22):104-116. Doi: 10.29298/rmcf.v5i22.353.

Comisión Nacional de Áreas Naturales Protegidas (Conanp). 2017. Programa de Manejo. Área de Protección de Flora y Fauna Papigochic. Secretaría de Medio Ambiente y Recursos Naturales (Semarnat) y Conanp. Miguel Hidalgo, Cd. Mx., México. 93 p.

Comisión Nacional de Áreas Naturales Protegidas (Conanp). 2023. Estudio previo justificativo para el establecimiento del Área Natural Protegida Santuario Cotorra Serrana. Conanp y Secretaría de Medio Ambiente y Recursos Naturales (Semarnat). Chihuahua, Chih., México. 242 p. https://www.conanp.gob.mx/pdf/separata/EPJ-S-CotorraSerranaOccidental.pdf. (21 de septiembre de 2023).

Comisión Nacional Forestal (Conafor). 2014. Inventario Estatal Forestal y de Suelos–Chihuahua 2013. Secretaría de Medio Ambiente y Recursos Naturales (Semarnat) y Conafor. Tlalpan, D. F., México. 160 p. https://transparencia.cnf.gob.mx/filesconafor/userfiles/IEFyS/IEFYS_Chihuahua_2013/IEFYS_Chihuahua_2013.pdf. (15 de abril de 2023).

Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio). 2023. Distribución de las especies. https://www.biodiversidad.gob.mx/especies/distribesp. (12 de julio de 2023).

Cortés M., C., P. Z. Fulé, D. A. Falk, J. Villanueva-Díaz and L. L. Yocom. 2012. Linking old-growth forest composition, structure, fire history, climate and land-use in the mountains of northern México. Ecosphere 3(11):1-16. Doi: 10.1890/ES12-00161.1.

Cruz A., A., M. Alfaro M., S. J. Solís J., E. D. Melgarejo y F. Rodríguez R. (Coords.). 2015. Estrategia para la Conservación y el Uso Sustentable de la Biodiversidad del estado de Chihuahua. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio). Tlalpan, D. F., México. 149 p. https://biblioteca.ecosur.mx/cgi-bin/koha/opac-detail.pl?biblionumber=57815. (14 de junio de 2024).

Cruz-Nicolás, J., J. J. Vargas-Hernández, P. Ramírez-Vallejo y J. López-Upton. 2008. Patrón de cruzamiento en poblaciones naturales de Pseudotsuga menziesii (Mirb.) Franco en México. Agrociencia 42(3):367-378. https://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952008000300011. (19 de septiembre de 2023).

Domínguez Á., F. A., J. J. Vargas H., J. López U., P. Ramírez V. y E. Guízar N. 2004. Aspectos ecológicos de Pseudotsuga menziesii en el ejido La Barranca, Pinal de Amoles, Querétaro. Anales del Instituto de Biología, Universidad Nacional Autónoma de México, Serie Botánica 75(2):191-203. http://revistas.unam.mx/index.php/bot/article/view/14656. (12 de agosto de 2023).

Domínguez-Calleros, P. A., G. A. Chávez-Flores, E. Rodríguez-Téllez, J. J. Corral-Rivas, J. R. Goche-Telles y M. A. Díaz-Vázquez. 2014. Caracterización silvícola de Pseudotsuga menziesii en la reserva de la biosfera "La Michilía". Madera y Bosques 20(2):23-31. Doi: 10.21829/myb.2014.202161.

Encina-Domínguez, J. A., F. J. Encina-Domínguez, E. Mata-Rocha y J. Valdes-Reyna. 2008. Aspectos estructurales, composición florística y caracterización ecológica del bosque de oyamel de la Sierra de Zapalinamé, Coahuila, México. Boletín de la Sociedad Botánica de México 83:13-24. https://www.scielo.org.mx/pdf/bsbm/n83/n83a2.pdf. (10 de septiembre de 2023).

Felger, R. S., G. P. Nabhan and R. Bye. 1997. Apachian/Madrean Region of South-western North America, Mexico and U.S.A. In: Davis, S. D., V. H. Heywood, O. Herrera-MacBryde, J. Villa-Lobos and A. C. Hamilton (Editors). Centres of plant diversity: a guide and strategy for their conservation. Vol. III. The Americas. The World Wide Fund for Nature (WWF) and International Union for the Conservation of Nature (IUCN). Cambridge, CBG, United Kingdom. 172-180 p.

García, E. 2004. Modificaciones al Sistema de clasificación climática de Köppen. Instituto de Geografía de la Universidad Nacional Autónoma de México. Coyoacán, D. F., México. 90 p.

García A., A. y M. S. González E. 2003. Pináceas de Durango. Instituto de Ecología, A. C. y Comisión Nacional Forestal (Conafor). Durango, Dgo., México. 187 p.

García G., S. A., E. Alanís R., O. A. Aguirre C., E. J. Treviño G. y G. Graciano Á. 2020. Regeneración y estructura vertical de un bosque de Pseudotsuga menziesii (Mirb.) Franco en Chihuahua, México. Revista Mexicana de Ciencias Forestales 11(58):92-111. Doi: 10.29298/rmcf.v11i58.665.

García-García, S. A., E. Alanís-Rodríguez, E. A. Rubio-Camacho, O. A. Aguirre-Calderón, E. J. Treviño-Garza y G. Graciano-Ávila. 2021. Patrones de distribución espacial del arbolado en un bosque de Pseudotsuga menziesii en Chihuahua, México. Madera y Bosques 27(3):1-15. Doi: 10.21829/myb.2021.2732242.

García-García, S. A., E. Alanís R., E. A. Rubio-Camacho, Ó. A. Aguirre-Calderón, … y A. Collantes C. 2024. Distribución espacial de Pinus y Quercus en un gradiente altitudinal de bosque templado en Guadalupe y Calvo, Chihuahua. Revista Mexicana de Ciencias Forestales 15(81):33-58. Doi: 10.29298/rmcf.v15i81.1426.

González C., R. 2019. Evaluación del estado actual de las poblaciones de Abies vejarii Martínez en el noreste de México. Tesis doctoral. Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León. Linares, NL, México. 106 p.

González C., R., E. J. Treviño G., M. A. González T., Á. Duque M. y M. Gómez C. 2018. Diversidad y estructura arbórea en un bosque de Abies vejarii Martínez en el sur del estado de Nuevo León. Revista Mexicana de Ciencias Forestales 9(45):36-64. Doi: 10.29298/rmcf.v9i45.142.

González E., M. S., M. González E. y M. A. Márquez L. 2006. Vegetación y ecorregiones de Durango. Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Durango del Instituto Politécnico Nacional (CIIDIR-IPN). Durango, Dgo., México. 165 p.

Graciano-Ávila, G., E. Alanís-Rodríguez, O. A. Aguirre-Calderón, M. A. González-Tagle, … y J. J. Corral-Rivas. 2020. Cambios estructurales de la vegetación arbórea en un bosque templado de Durango, México. Acta Botánica Mexicana (127):1-16. Doi: 10.21829/abm127.2020.1522.

Guerra De la C., V., J. C. López-Domínguez, J. López U., C. Bautista S. y L. Hernández G. 2012. Estructura silvícola de poblaciones de Pseudotsuga menziesii (Mirb.) Franco en Tlaxcala y Puebla. Revista Mexicana de Ciencias Forestales 3(13):73-88. Doi: 10.29298/rmcf.v3i13.490.

Guzmán L., M. A. 2009. Distribución, sistemática, y algunos aspectos ecológicos del mezquite Prosopis spp. (L.) en el estado de Nuevo León, México. Tesis de Doctorado. Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León. San Nicolás de los Garza, NL, México. 197 p.

Hammer, Ø., D. A. T. Harper and P. D. Ryan. 2001. Past: Paleontological Statistics Software Package for Education and Data Analysis. Palaeontologia Electronica 4(1):1-9. https://palaeo-electronica.org/2001_1/past/past.pdf. (24 de mayo de 2022).

Harrison, T., J. Gibbs and R. Winfree. 2019. Anthropogenic landscapes support fewer rare bee species. Landscape Ecology 34(5):967-978. Doi: 10.1007/s10980-017-0592-x.

Hemp, A. 2005. Continuum or zonation? Altitudinal gradients in the forest vegetation of Mt. Kilimanjaro. Plant Ecology 184:27-42. Doi: 10.1007/s11258-005-9049-4.

Hutcheson, K. 1970. A test for comparing diversities based on the Shannon formula. Journal of Theoretical Biology 29(1):151-154. Doi: 10.1016/0022-5193(70)90124-4.

Huuskonen, S., T. Domisch, L. Finér, J. Hantula, … and H. Viiri. 2021. What is the potential for replacing monocultures with mixed-species stands to enhance ecosystem services in boreal forests in Fennoscandia? Forest Ecology and Management 479:118558. Doi: 10.1016/j.foreco.2020.118558.

Instituto Nacional de Estadística y Geografía (INEGI). 2014. Conjunto de datos de erosión del suelo, Escala 1: 250 000 Serie I Continuo Nacional. (2014). https://www.inegi.org.mx/app/biblioteca/ficha.html?upc=702825004223. (25 de mayo de 2022).

Instituto Nacional de Estadística y Geografía (Inegi). 2018. Conjunto de datos vectoriales de uso del suelo y vegetación. Escala 1:250 000. Serie VII. Conjunto Nacional (2018). https://www.inegi.org.mx/app/biblioteca/ficha.html?upc=889463842781. (25 de mayo de 2022).

Jardel P., E. J. 2015. Criterios para la conservación de la biodiversidad en los programas de manejo forestal. Comisión Nacional Forestal (Conafor) y Programa de las Naciones Unidas para el Desarrollo (PNUD). Zapopan, Jal., México. 126 p.

Jost, L. 2006. Entropy and diversity. Oikos 113(2):363-375. Doi: 10.1111/j.2006.0030-1299.14714.x.

Keesing, F. and R. S. Ostfeld. 2024. The more, the healthier: Tree diversity reduces forest pests and pathogens. PLoS Biology 22(2):e3002525. Doi: 10.1371/journal.pbio.3002525.

Lozada D., J. R. 2010. Consideraciones metodológicas sobre los estudios de comunidades forestales. Revista Forestal Venezolana 54(1):77-88. http://www.ula.ve/ciencias-forestales-ambientales/indefor/wp-content/uploads/sites/9/2017/01/2010_ConsMetEstComVeg_orig.pdf. (10 de diciembre de 2023).

Luna-Vega, I., O. Alcántara A. and R. Contreras-Medina. 2010. Threatened temperate plant species: Contributions to their biogeography and conservation in México. In: Tepper, G. H. (Edit.). Species diversity and extinction. Nova-Science Publishers. Hauppauge, NY, United States of America. pp. 317-339.

Magurran, A. E. 2004. Measuring biological diversity. Blackwell Science, Ltd. Oxford, OX, United Kingdom. 256 p.

Mápula-Larreta, M., J. López-Upton, J. J. Vargas-Hernádez and A. Hernández-Livera. 2007. Reproductive indicators in natural populations of Douglas-fir in Mexico. Biodiversity and Conservation 16(3):727-742. Doi: 10.1007/s10531-005-5821-y.

Martínez-Sifuentes, A. R., J. A. Hernández-Herrera, L. M. Valenzuela-Núñez, E. A. Briceño-Contreras, … and M. J. López C. 2022. Climate change impact on the habitat suitability of Pseudotsuga menziesii (Mirb.) Franco in Mexico: An approach for its conservation. Sustainability 14(14):8888. Doi: 10.3390/su14148888.

McCain, C. M. and J. A. Grytnes. 2010. Elevational gradients in species richness. In: Nature Publishing Company and John Wiley & Sons. Encyclopedia of Life Sciences. John Wiley & Sons, Ltd. Hoboken, NJ, United States of America. pp. 1-10.

Méndez O., C., C. A. Mora D., E. Alanís R., J. Jiménez P., ... y M. Á. Pequeño L. 2018. Fitodiversidad y estructura de un bosque de pino-encino en la Sierra Madre del Sur, México. Revista Mexicana de Ciencias Forestales 9(50):35-53. Doi: 10.29298/rmcf.v9i50.236.

Molina-Marchan, E., R. Narváez-Flores y A. S. Mojica-Guerrero. 2024a. Estructura horizontal y diversidad de los bosques de Pseudotsuga menziesii (Mirb.) Franco en México. Polibotánica 57(29):63-80. Doi: 10.18387/polibotanica.57.4.

Molina-Marchan, E., R. Narváez-Flores y A. S. Mojica-Guerrero. 2024b. Distribución de los bosques de Pseudotsuga menziesii (Mirb.) Franco en México. E-CUCBA 11(21):59-67. Doi: 10.32870/e-cucba.vi21.323.

Moreno, C. E., F. Barragán, E. Pineda y N. P. Pavón. 2011. Reanálisis de la diversidad alfa: alternativas para interpretar y comparar información sobre comunidades ecológicas. Revista Mexicana de Biodiversidad 82(4):1249-1261. Doi: 10.22201/ib.20078706e.2011.4.745.

Moreno, C. E. 2001. Métodos para medir la biodiversidad. Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (Cyted), Oficina Regional de Ciencia y Tecnología para América Latina y el Caribe de la Unesco y Sociedad Entomológica Aragonesa (SEA). Zaragoza, Zgz., España. 84 p.

Moreno V., M. E., T. G. Domínguez G., M. del S. Alvarado, J. G. Colín, S. Corral R. y H. González R. 2018. Aporte y descomposición de hojarasca en bosques templados de la región de El Salto, Durango. Revista Mexicana de Ciencias Forestales 9(47):70-93. Doi: 10.29298/rmcf.v9i47.180.

Pompa-García, M., J. Á. Sigala R. and E. Jurado. 2017. Some tree species of ecological importance in Mexico: A documentary review. Revista Chapingo Serie Ciencias Forestales y del Ambiente 23(2):185-219. Doi: 10.5154/r.rchscfa.2016.05.032.

QGIS Development Team. 2023. QGIS (Version 3.30.2). Santa Cruz, CA, United States of America. Geographic Information System. https://qgis.org. (28 de mayo de 2023).

Royo-Márquez, M. H., A. Melgoza-Castillo y G. Quintana-Martínez. 2014. Especies vegetales en peligro, su distribución y estatus de conservación de los ecosistemas donde se presentan. Revista Mexicana de Ciencias Forestales 5(22):86-103. Doi: 10.29298/rmcf.v5i22.352.

Rzedowski, J. 2006. Vegetación de México. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio). Tlalpan, D. F., México. 504 p.

Sánchez M., G., C. J. Mehmel, N. E. Gillette, E. González G., … y L. M. Torres E. 2012. Fundamentos para el control integral del descortezador Dendroctonus pseudotsugae barragani Furniss en México. INIFAP-CIRNOC-Campo Experimental Pabellón. Pabellón de Artega, Ags., México. 54 p.

Spellerberg, I. F. 1991. Monitoring ecological change. Cambridge University Press. Cambridge, Cambs., United Kingdom. 334 p.

Stirling, G. and B. Wilsey. 2001. Empirical relationships between species richness, evenness, and proportional diversity. The American Naturalist 158(3):286-299. Doi: 10.1086/321317.

Stock Informático. 2013. Cartografía de Uso de Suelo y Vegetación del Estado de Chihuahua. Escala 1: 50 000 (2013). Gobierno del Estado de Chihuahua y Secretaría de Desarrollo Rural. Chihuahua, Chih., México. 97 p.

Thompson, I. 2011. Biodiversidad, umbrales ecosistémicos, resiliencia y degradación forestal. Unasylva Revista Internacional de Silvicultura e Industrias Forestales 62:25-30. https://www.ucipfg.com/Repositorio/MGAP/MGAP-10/SEMANA1/07.pdf. (30 de septiembre de 2023).

Vargas-Hernández, J. J., J. López-Upton, V. J. Reyes-Hernández, F. A. Domínguez-Álvarez and M. Mapula-Larreta. 2003. Natural populations of Douglas-fir in Mexico: Current status and needs for conservation. In: Beaulleu, J. (Edit.). Silviculture and the conservation of genetic resources for sustainable forest management. Proceedings of the symposium of the North American Forest Commission, Forest Genetic Resources and Silviculture Working Groups, and the International Union of Forest Research Organizations (IUFRO). Natural Resources Canada, Canadian Forest Service and Laurentian Forestry Centre. Quebec, QC, Canada. pp. 26-36.

Vargas L., B. 2013. Manual de mejores prácticas de manejo forestal para la conservación de la biodiversidad en ecosistemas templados de la región norte de México. Comisión Nacional Forestal (Conafor) y Programa de las Naciones Unidas para el Desarrollo (PNUD). Zapopan, Jal., México. 86 p.

Velasco-García, M. V., J. López-Upton, G. Ángeles-Pérez, J. Vargas-Hernández y V. Guerra-de la Cruz. 2007. Dispersión de semillas de Pseudotsuga menziesii, en poblaciones del centro de México. Agrociencia 41:121-131. https://www.agrociencia-colpos.org/index.php/agrociencia/article/view/523/523. (25 de octubre de 2023).

Ventura R., A., J. López U., J. J. Vargas H. y V. Guerra de la C. 2010. Caracterización de Pseudotsuga menziesii (Mirb.) Franco en el centro de México. Implicaciones para su conservación. Revista Fitotecnia Mexicana 33(2):107-116. https://www.scielo.org.mx/scielo.php?pid=S0187-73802010000200003&script=sci_abstract. (11 de enero de 2024).

Villanueva D., J., D. W. Stahle, M. K. Cleaveland y M. D. Therrell. 2000. Estado actual de la dendrocronología en México. Revista Ciencia Forestal en México 25(88):5-36. https://cienciasforestales.inifap.gob.mx/index.php/forestales/article/view/921. (10 de septiembre de 2023).

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