Changes in climate and the intensity of agriculture expansion can alter plant population dynamics and community composition and structure of dry shrublands.We tested how temperature and moisture al...

Tropical dry forests are among the most threatened ecosystems globally, yet the consequences of livestock overgrazing for ant communities remain poorly documented, particularly in the Tumbesian biodiversity hotspot of southwestern Ecuador, where uncontrolled goat grazing constitutes the dominant disturbance agent. We sampled ant communities (Formicidae) across a goat-grazing disturbance gradient in Zapotillo (Loja Province, Ecuador), establishing three disturbance levels (Dense, Semi-dense, and Open Forest) with nine 60 × 60 m plots per level (n = 27) and 486 pitfall traps. Community responses were assessed using abundance-based and presence–absence analyses of morphospecies richness, Hill-number diversity, community composition, beta diversity decomposition, and functional guild structure; vegetation structure was characterized using satellite-derived NDVI. We recorded 47,459 individuals belonging to 22 morphospecies in six subfamilies. Morphospecies richness declined with disturbance (Dense: 19, Semi-dense: 15, Open: 12), with four specialist genera exclusive to Dense Forest. Beta diversity decomposition revealed a shift from turnover-dominated dissimilarity at moderate disturbance to nestedness-dominated dissimilarity at high disturbance, indicating progressive habitat filtering as the dominant community-restructuring process. Community composition differed among disturbance levels (PERMANOVA: F = 4.49, R² = 0.272, p = 0.001) and was correlated with NDVI (r² = 0.341, p = 0.013). Cryptic/soil and Leaf-cutter guilds were nearly eliminated from Open forest while the Opportunist guild expanded markedly, indicating that functional homogenization precedes detectable taxonomic impoverishment. Overgrazing drives directional ant diversity loss and biotic homogenization at both taxonomic and functional levels in the Tumbesian dry forest, underscoring the conservation value of intact Dense forest.

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.