Tropical landscapes are dominated by land‐use systems, but their contribution to the conservation of biodiversity is largely unknown. Since changes in biodiversity in response to human impact are known to differ widely among taxonomic groups and guilds, there is a need for multidisciplinary collaboration of plant, vertebrate, and invertebrate experts. We used inventories of trees, understory plants, birds (subdivided into endemics, insectivores, frugivores/nectar feeders), butterflies (endemics, fruit feeders), and dung beetles in Sulawesi (Indonesia) to characterize a gradient from near‐primary to secondary forests, agroforestry systems, and annual crops. As expected, overall species richness tended to decrease within this gradient of increasing habitat modification, but, in contrast to previous studies, we found the species richness between most taxonomic groups to be significantly correlated (36 out of 38 pairwise comparisons). However, on average only 48% of the variance could be explained (within the five main groups), and only a few taxonomic groups/guilds turned out to be good predictors for others: for example, trees for fruit‐ and nectar‐feeding birds (88% explanation) and fruit‐feeding butterflies (83%), endemic birds for endemic butterflies (72%), and frugivorous/nectar‐feeding birds for fruit‐feeding butterflies (67%). Although biodiversity of land‐use systems showed taxonomic group‐ and guild‐specific differences, most groups were affected in a similar way by habitat modification. Near‐primary forest sites proved to be of principal importance for conservation; however, land‐use systems such as secondary forests (for understory plants, birds, and butterflies) and agroforestry systems (for butterflies) supported relatively high numbers of species and might play a significant role for biodiversity conservation in tropical landscapes.

The island of Sulawesi is the largest in Indonesian Wallacea, one of the most important ecoregions in SE Asia and globally. Here, we generate a comprehensive and detailed map of forest type, its condition, and some of its threats, which highlights key forest conservation areas, pinpoints frontlines within them, and provides the basis for the development of more specific objectives. We relied upon a variety of techniques to generate five main descriptors of forest quality: condition, its level of endangerment, its landscape setting, its simulated fate given a simple model of forest change, and its overall size. Using the results of this analysis, we assessed the existing protected areas (PA), recognized by the Indonesian government, and a conservation portfolio (CP) generated by a recently completed Ecoregional Conservation Assessment (ECA). Our map of conservation priorities is congruent with previous conservation activities, although several priority areas were identified outside of the current PA system and should be the focus of strategic protected area development. Our ranking system is simple, transparent, and flexible. Its modular construction will allow local managers to choose among available proxy measures and to add their own conservation values according to specific priorities and desired outcomes. We envision this analysis as the foundation upon which more specific conservation strategies, based upon detailed biotic information as it becomes available, can be developed.

The Spathelia-Ptaeroxylon clade is well placed in Rutaceae and it is reasonable to unite the genera into one subfamily (Spathelioideae). We propose a new tribal classification of Spathelioideae. A narrow circumscription of Spathelia is established to make the genus monophyletic, and Sohnreyia is resurrected to accommodate the South American species of Spathelia. The most recent common ancestor of Spathelioideae probably had leaves with secretory cavities and oil cells, haplostemonous flowers with appendaged staminal filaments, and a tracheidal tegmen.