Effect of forest management on tree diversity in temperate ecosystem forests in northern Mexico

Abstract

An important challenge for silvicultural practices is the conservation of tree diversity while fulfilling the traditional objectives of forest management, most notably timber harvesting. The purpose of this study was to compare the tree diversity before and after the application of silvicultural treatments in a temperate forest in northern Mexico. Fifteen experimental plots, each measuring 2500 m 2 , were established to evaluate the immediate effect of four silvicultural treatments. These treatments were identified by their levels of management: intensive (clearcut, removal 100%), semi-intensive (removal of 59-61% of basal area), conservative (removal of 29-31% of basal area), and a control group. New forest guidelines, in contrast to conventional approaches, were applied to the semi-intensive and conservative treatments based on health and diversity conditions. Basal area, canopy cover, tree and total volume were measured in each plot. The Importance Value Index, alpha diversity, and evenness were estimated before and after treatments. Eighteen species belonging to five genera and five families were found in the study area. The species with the highest ecological values were Pinus durangensis, P. teocote, Quercus sideroxyla, and Quercus convallata with IVI numbers between 13.6 and 24.5%. Alpha diversity was intermediate (Margalef: 2.9 to 3.8), while dominance and evenness were above average compared to other studies (Simpson: 0.69 to 0.77; Shannon-Wiener: 1.44 to 1.6; Pielou: 0.76 to 0.85). The species evenness index in the conservative treatment was high (Sorensen, Jaccard, quantitative Sorensen and Morisita-Horn; 88 to 99%), although abundance decreased. Overall, there were no significant differences in IVI values and diversity indicators before and after treatments, with the exception of the clearcut treatment. When associating the diversity indices with stand variables, only the Pielou's evenness index showed a significant relationship between them. We concluded that both the conservative and semi-intensive treatments did not generate significant changes in tree diversity, but the former had slightly higher alpha diversity indices. These results can provide a better insight on silvicultural practices and their effects on species composition.

Effects of stand variables on stemflow and surface runoff in pine-oak forests in northern Mexico

“…They allowed us to conduct research and field measurements on their property. The current management plan includes the application of non-intensive tree regeneration methods (selective harvesting) as well as intensive methods (seed tree retention or clear-cuts) in different parts of the property [18,26]. Of the total area, about 2,050 ha are under timber management, with the following treatment distribution: clear-cuts 3.5%, tree retention 14%, thinning 27%, and individual selection 55.5% [26].…”

“…Intensive silvicultural treatments (e.g. stand thinning from above or clear-cutting) change forest density [18], eventually modifying throughfall and stemflow at both stand level and individual tree level [19], while increasing surface runoff [20]. The potential impact of the increased water from the surface flow may eventually affect site productivity and the provision or regulation of other ecosystem services (e.g., plant diversity, soil erosion control, carbon sequestration, etc.)…”

The Connections between Above-Ground Biomass and Plant Diversity of Roadside Trees, Density and Diversity on Different Types of Roads in Karachi

“…The relationship between diversity and biomass could be characterized by diversity indicators such as Simpson [9] and Pielou [10]. Sun et al [2] applied these indices to study other climate types in China, such as northern Mexico [11]. While studies on biomass and species diversity have been conducted in other locations, such as the tropical forests of Hainan Island, Southern China [12], Karachi City as a representative of Pakistan tropical coastal city, has not been assessed.…”

Mid-term Impacts of Silvicultural Treatments on Soils and Understory Plant Diversity in Temperate Hardwood Forests of Quebec, Canada.

“…The taxonomic approach can detect the presence of rare species, but its indicators have low analytical power to characterize biodiversity and the effects of disturbance on ecosystem functions (Daly et al 2018;Willis and Martin 2020). Consequently, substantial variations in understory plant diversity not only remain very di cult to measure, but also di cult to predict along a disturbance intensity gradient on the basis of species richness alone, for example, using meta-analyses (Gilliam and Roberts 1995 Nolet et al 2018). In contrast, the functional approach provides more information on the processes of species responses to biotic and abiotic conditions (Aubin et al 2007;Lavorel et al 2007).…”

“…Yet, these communities exhibit increased environmental sensitivity that could be exacerbated by repeated harvesting pressures that disturb both the soil and forest cover (Roberts and Zhu 2002;Ellum 2009). Since the 1990s, researchers have been interested in the relationships between silvicultural treatment intensi cation (i.e., increased disturbance intensity or frequency; Foley et al 2005), forest productivity and biodiversity (Gilliam and Roberts 1995;Brockerhoff et al 2008;Paquette and Messier 2010). Some have suggested that intensi cation required of forest management practices threatens forest landscapes (e.g., through decreases in structural complexity; Chaudhary et al 2016) and biodiversity (e.g., changes in species composition, decreases in heterogeneity and functional diversity; Lindenmayer 2012Lindenmayer , 2016Gauthier et al 2016;Yeboah et al 2016;Messier et al 2019).…”