• Energy Research

AbstractAimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.

Biomass plays a vital role in the energy supply of many developing countries. It is the major energy source for the rural population of Nepal, where 70 % of the total energy is derived from woody plant biomass in the form of fuelwood. The main aim of this study is to describe the fuelwood consumption pattern and the role of community forests and trees on private farmland in biomass supply to rural households in Nepal. The study investigates whether demography and socioeconomic attributes of households affect fuelwood consumption. A household survey was conducted, along with measurements of fuelwood mass for six community forest user groups in Dolakha district of Nepal. Average daily household fuelwood consumption was estimated to be 8.4 kg, giving a mean annual consumption of 3060 kg per household. Per capita fuelwood consumption per day was found to be 1.7 kg. Total fuelwood consumption of households is significantly correlated with household size, ownership of cultivated irrigated terraces and number of livestock per household, and negatively significantly correlated with ownership of cultivated rain-fed terraces. Fuelwood consumption varies significantly between seasons. Among various sources of biomass energy, fuelwood from community forests contributes 23 % and trees on private farmland contribute 12 %. The rest is provided from other biomass sources, including the remains of fodder collected from private farmland vegetation, wood previously used for fences and trellises in private farmland, crop residues, and purchased fuelwood.