The dry forest of southern Ecuador and northern Perú (called the Tumbesian region) is known for its high diversity, endemism, and healthy conservation state. Nevertheless, the forest is exposed to many threats linked with human activities. To understand the effects of these threats, which have not been appropriately assessed, we pose two questions: (a) What are the diversity and structural situations of the forest? (b) Are anthropogenic activities affecting the composition and structure of the forest? The assessed factors were species richness, diversity, species similarity, abundance, and density. Forest information was obtained from 72 plots (total area 25.92 ha) randomly placed to cover a wide range of stand densities (from 200 to 1100 m a.s.l.). After constructing linear mixed models and selecting the most influential one, we determined the individual influences of 12 predictors. The human pressure index (HPI) was the most negative predictor of forest health, and annual precipitation was the most important abiotic predictor of good health conditions. Livestock grazing did not significantly change the diversity and structure of mature forest. The mean annual temperature and stoniness influenced only the basal area and number of individuals, respectively. The species composition in our study area was not affected by the HPI, but was strongly predicted by annual precipitation.

The dry forests of southern Ecuador are characterized by a great floristic variety and high endemism rates in different taxonomic groups; however, these forests are disappearing at an alarming rate due to anthropogenic disturbances. Epiphytic cryptogams (bryophytes and lichens) are important in seasonally dry tropical forests (SDTFs) and, due to their physiology (poikilohydric species), are sensitive to the changes associated with specific human disturbances. We examined the response of epiphytic cryptogams to habitat disturbance in SDTFs (natural and semi-natural forests) by registering the frequency and coverage of epiphytic cryptogams on 182 trees. We recorded a total of 53 epiphytic cryptogams (47 lichens and 6 bryophytes). A greater number of species was found in the natural forest, with 51 species, than the semi-natural forests (DFs), which had 45 species. We found that total richness tended to decrease with increased intensity of disturbance. The impoverishment was particularly related to the reduction in tree density and diversity (e.g., selective logging) in semi-natural compared to natural forests. However, the epiphytic composition showed little relationship with forests disturbance. We conclude that anthropic disturbance, particularly selective logging, are the main factors affecting the diversity of epiphytic cryptogams in the SDTFs from southern Ecuador.

Root anatomical traits regulate water transport and resource acquisition in forest ecosystems, yet their variation and coordination with aboveground traits remain poorly understood in tropical forests. We investigated patterns of interspecific variation in four root anatomical traits (vessel diameter, vessel density, vessel lumen fraction, and theoretical hydraulic conductivity) across 20 tree species representing contrasting growth strategies in a premontane tropical forest of southern Ecuador. Using 160 root samples from transport roots (4–8 mm diameter), we quantified anatomical traits through microscopy and calculated theoretical hydraulic conductivity. We analyzed correlations with wood density and leaf functional traits and performed principal component analyses to assess trait coordination. Species exhibited substantial variation in root anatomical traits, ranging from acquisitive strategies with large vessel diameters (67.6 μm in Ocotea sp.) and high hydraulic conductivity (73.9 kg m⁻¹ MPa⁻¹ s⁻¹ in Alchornea glandulosa) to conservative strategies with high vessel density (>185 vessels/mm² in Leonia crassa and Aspidosperma rigidum). However, 60% of species displayed intermediate trait values, suggesting compensatory strategies rather than extreme specialization. We documented strong negative correlations between vessel diameter and both vessel density (r = −0.74) and wood density (r = −0.51), pointing at hydraulic efficiency-safety trade-offs. Principal component analysis revealed that leaf traits operated orthogonally to root anatomical traits, indicating independent axes of functional variation rather than coordinated whole-plant strategies. These decoupling challenges traditional plant economics spectrum assumptions and evidence that plants optimize above- and belowground functions through independent evolutionary pathways. Our findings highlight the prevalence of intermediate hydraulic strategies in tropical tree communities and provide new insights into the functional organization of diverse forest ecosystems.

Ex situ seed collections support dry-forest restoration, yet how much germination capacity tropical tree seeds retain under ambient, non-refrigerated storage is rarely documented beyond a few years. We compared historical seed lots of five native tree species from the Tumbesian dry forests of southern Ecuador, kept for 12 to 17 years in paper bags under uncontrolled laboratory conditions, with freshly collected lots, sowing 948 seeds. Because the lots are independent collections without initial germination data, all comparisons are observational and describe retained germination capacity rather than isolated storage effects; ungerminated seeds were not tested for viability. Historical lots germinated less than fresh lots in four species (58–87% lower); overall, 15.6% of historical and 48.1% of fresh seeds germinated. The difference was largest in Ceiba trichistandra (10.4% vs. 81.2%) and absent in Caesalpinia spinosa (25.0% vs. 27.1%), whose low fresh-lot germination may reflect physical dormancy. Coccoloba ruiziana, regionally listed as recalcitrant, still germinated at 23% after 14 years, which is inconsistent with recalcitrant behavior and supports treating it as intermediate. Relative loss increased with years in storage, but this exploratory association is confounded with species and collection year. Only C. ruiziana produced clearly shorter seedlings from historical seed. Decade-old ambient holdings can still yield seedlings, but sowing quantities must be species-specific.