Resumen

MOLINA-MARCHAN, Emanuel; NARVAEZ-FLORES, Raúl  y  MOJICA-GUERRERO, Aldo Saúl. Horizontal structure and diversity of the Pseudotsuga menziesii (Mirb) Franco forests in Mexico. Polibotánica [online]. 2024, n.57, pp.63-80.  Epub 19-Abr-2024. ISSN 1405-2768.  https://doi.org/10.18387/polibotanica.57.4.

Assessing diversity allows us to know the general state of ecological systems, the impact of climate change, forest management and other anthropic activities, and has been used for practical purposes of conservation, monitoring and management of forests. The objective of the study was to analyze the structure, diversity and similarity of the tree stratum of Pseudotsuga menziesii forests in Mexico, a species listed in NOM-059-SEMARNAT-2010, whose areas are considered of High Conservation Value. The present study included 11 of the 14 states where this species is distributed in Mexico. Information from 28 Pseudotsuga communities was analyzed and processed, obtained from the National Forest and Soil Inventory, research works and own information; horizontal structure was determined with the Importance Value Index (IVI), diversity with the Shannon-Wiener (H') and Pielou (J) index, significant

differences in diversity were determined with the Hutcheson's t-test, and floristic similarity was obtained with the Morisita-Horn index. At the national level, 9 families, 14 genera and 45 species were recorded, the IVI of Pseudotsuga fluctuates between 20.77 and 53.33; H' values generally indicate low diversity (<2.00) and high J-equity (>0.70). The Morisita index presents three groupings corresponding to the physiographic provinces Sierra Madre Occidental, Sierra Madre Oriental and Faja Volcánica Transmexicana, and reflects a high similarity within each province and medium to low similarity between regions. This work will contribute to the development of management strategies for monitoring and conservation in these forests.

Palabras llave : Douglas-fir Forest; ecology; conservation; effective species; species richness; community similarity.