The biodiversity hotspot of the Equatorial Pacific region in western Ecuador and northwestern Peru comprises the most extensive seasonally dry forest formations west of the Andes. Based on a recently assembled checklist of the woody plants occurring in this region, we analysed their geographical and altitudinal distribution patterns. The montane seasonally dry forest region (at an altitude between 1,000 and 1,100 m, and the smallest in terms of area) was outstanding in terms of total species richness and number of endemics. The extensive seasonally dry forest formations in the Ecuadorean and Peruvian lowlands and hills (i.e., forests below 500 m altitude) were comparatively much more species poor. It is remarkable though, that there were so many fewer collections in the Peruvian departments and Ecuadorean provinces with substantial mountainous areas, such as Cajamarca and Loja, respectively, indicating that these places have a potentially higher number of species. We estimate that some form of protected area (at country, state or private level) is currently conserving only 5% of the approximately 55,000 km 2 of remaining SDF in the region, and many of these areas protect vegetation at altitudes below 500 m altitude. In contrast, the more diverse seasonally dry forests in mountainous areas remain little protected.

Understanding the vulnerability of tree species to anthropogenic threats is important for the efficient planning of restoration and conservation efforts. We quantified and compared the effects of future climate change and four current threats (fire, habitat conversion, overgrazing and overexploitation) on the 50 most common tree species of the tropical dry forests of northwestern Peru and southern Ecuador. We used an ensemble modelling approach to predict species distribution ranges, employed freely accessible spatial datasets to map threat exposures, and developed a trait-based scoring approach to estimate species-specific sensitivities, using differentiated trait weights in accordance with their expected importance in determining species sensitivities to specific threats. Species-specific vulnerability maps were constructed from the product of the exposure maps and the sensitivity estimates. We found that all 50 species face considerable threats, with an average of 46% of species' distribution ranges displaying high or very high vulnerability to at least one of the five threats. Our results suggest that current levels of habitat conversion, overexploitation and overgrazing pose larger threats to most of the studied species than climate change. We present a spatially explicit planning strategy for species-specific restoration and conservation actions, proposing management interventions to focus on (a) in situ conservation of tree populations and seed collection for tree planting activities in areas with low vulnerability to climate change and current threats; (b) ex situ conservation or translocation of populations in areas with high climate change vulnerability; and (c) active planting or assisted regeneration in areas under high current threat vulnerability but low climate change vulnerability, provided that interventions are in place to lower threat pressure. We provide an online, user-friendly tool to visualize both the vulnerability maps and the maps indicating priority restoration and conservation actions. K E Y W O R D S functional traits, multithreat vulnerability, restoration and conservation planning, sensitivity, tropical dry forest FREMOUT ET al. | 3553Vulnerability

Forest restoration projects involving active planting should prioritize species that are useful to local communities, while also considering species' threat status and resistance to local stress factors, but scientific knowledge on these criteria is scarce, especially in understudied tropical ecosystems. We hypothesized that local ecological knowledge can help to fill this gap. Through interviews with 47 local experts and 197 randomly selected households in 8 rural communities of the tropical dry forests of northwestern Peru and southern Ecuador, we identified the species perceived as most useful, most threatened, and most resistant to local stress factors. To better understand the studied local ecological knowledge, we also explored the following research questions and their implications for species selection decisions: (1) How does species' potential usefulness compare to their active use? (2) How does species' perceived threat status relate to their usefulness? (3) Does local knowledge on species' resistance to local stress factors corroborate scientific knowledge? We found large differences between the potential and active use of species and illustrate how data on both can yield useful insights. Furthermore, we found that species' perceived threat status was mainly linked to their usefulness for construction wood, and that the vast majority of local perceptions on species' threat status and stress resistance coincided with scientific knowledge. Our findings illustrate the large potential of local ecological knowledge for improving species selection strategies and thereby increasing the success of forest restoration efforts worldwide.

Tropical and subtropical dry forests make up the world's largest terrestrial ecosystem. However, these forests have been used to establish several productive activities, such as growing crops, rearing livestock, and using the forest resources, due to their ease of access and climatic conditions, which has led to this ecosystem becoming highly threatened. Therefore, this research assessed the effects of anthropogenic pressures and a number of abiotic variables on natural regeneration in dry forests in the Tumbesian region by addressing three research questions: (a) What is the status of natural regeneration in terms of abundance and diversity? (b) Does livestock grazing and the anthropogenic pressure affect the abundance and diversity of natural regeneration? (c) Does seasonality or grazing have the greatest influence on the regeneration dynamics? Data were obtained from 72 samples (36 fenced and 36 unfenced) during five surveys spanning a 2-year period, and the seedling abundance, mortality, recruitment, species richness and diversity were evaluated using linear mixed models. Natural regeneration was most positively affected by rainy season precipitation, but soil conditions also played an important role. Short-term fences had a major effect on reducing mortality but did not improve the abundance or diversity, whereas cattle grazing significantly affected the abundance of seedlings. Scientists have been depicting the threats that tropical dry forests are exposed to for many years 1-6 and have identified some parts of this ecosystem as places of tremendous diversity and endemism 7-9. These insights have supported the establishment of new protected areas in several regions of the world-for instance, the Brazilian Minister of the Environment identified 52 priority areas for conservation in the Caatinga in 2002, 27 of which were catalogued as an extreme priority 10 ; Koleff et al. 11 stated in 2012 that 42% of the Mexican tropical dry forests should be protected; several private and state-owned areas were added to the list of protected areas in Ecuador, including the 'Bosques de Paz' Biosphere Reserve, in 2017 12 ; and one of the most representative areas of Peru was placed under protection by the Amazonas Department in 2018 13. However, although the number of protected areas has increased and a large amount of research has been undertaken on the biophysical aspects of tropical dry forests of Latin America, Caribbean and Africa 14,15 , little is known about the ecology and regeneration of tropical dry forests 16 or the effects of domestic animals and other threats on the natural regeneration of these forests, which are still diminishing in size 14. The tropical dry forest that extends along the Pacific coast from the southwest of Ecuador to the northwest of Peru covers approximately 64,500 km 2 17 and faces similar issues 18. This region, which is named the 'Tumbesian region' , is known for its high level of endemism among woody species 7,19 and for being one of the better preserved areas in the region 20,21. Some ef...