W. John Kress’s research while affiliated with Smithsonian Institution and other places

As multiple UN fora develop parallel rules for sharing benefits from digital sequence information, we urge better coordination. International policymakers should focus on harmonizing new benefit-sharing rules to ensure open access to data, database interoperability, and better benefit-sharing outcomes.

Habitat fragmentation remains a major focus of research by ecologists decades after being put forward as a threat to the integrity of ecosystems. While studies have documented myriad biotic changes in fragmented landscapes, including the local extinction of species from fragments, the demographic mechanisms underlying these extinctions are rarely known. However, many of them—especially in lowland tropical forests—are thought to be driven by one of two mechanisms: (1) reduced recruitment in fragments resulting from changes in the diversity or abundance of pollinators and seed dispersers or (2) increased rates of individual mortality in fragments due to dramatically altered abiotic conditions, especially near fragment edges. Unfortunately, there have been few tests of these potential mechanisms due to the paucity of long‐term and comprehensive demographic data collected in both forest fragments and continuous forest sites. Here we report 11 years (1998–2009) of demographic data from populations of the Amazonian understory herb Heliconia acuminata (LC Rich.) found at Brazil's Biological Dynamics of Forest Fragments Project (BDFFP). The data set comprises >66,000 plant × year records of 8586 plants, including 3464 seedlings established after the first census. Seven populations were in experimentally isolated fragments (one in each of four 1‐ha fragments and one in each of three 10‐ha fragments), with the remaining six populations in continuous forest. Each population was in a 50 × 100 m permanent plot, with the distance between plots ranging from 500 m to 60 km. The plants in each plot were censused annually, at which time we recorded, identified, marked, and measured new seedlings, identified any previously marked plants that died, and recorded the size of surviving individuals. Each plot was also surveyed four to five times during the flowering season to identify reproductive plants and record the number of inflorescences each produced. These data have been used to investigate topics ranging from the way fragmentation‐related reductions in germination influence population dynamics to statistical methods for analyzing reproductive rates. This breadth of prior use reflects the value of these data to future researchers. In addition to analyses of plant responses to habitat fragmentation, these data can be used to address fundamental questions in plant demography and the evolutionary ecology of tropical plants and to develop and test demographic models and tools. Though we welcome opportunities to collaborate with interested users, there are no restrictions on the use of this data set. However, we do request that those using the data for teaching or research purposes inform us of how they are doing so and cite this paper and the data archive when appropriate. Any publication using the data must also include a BDFFP Technical Series Number in the Acknowledgments. Authors can request this series number upon the acceptance of their article by contacting the BDFFP's Scientific Coordinator or E. M. Bruna.

The complex spatial structure and dynamics of ecological communities continue to defy explanation by simple principles despite decades of attention from ecologists and theoreticians. For example, the relationship between plant spatial distributions and species coexistence is often challenging to resolve in empirical settings. By analysing the spatial patterns of trees in 21 large forest plots we find a general and strong latitudinal gradient in the relationship between conspecific aggregation and abundance of tree species, with stronger negative abundance-dependency as latitude increases. To derive theoretical expectations for how interactions between multiple spatial pattern and processes can impact species coexistence, we incorporate the observed spatial patterns together with neighbourhood crowding competition into a mathematical model to estimate the local extinction risk of species. Strikingly, we find simple relationships that predict species local extinction risk from their demography and spatial distribution. Compared to a corresponding non-spatial analysis, accounting for spatial patterns reduces the 1000-year extinction risk on average by 52% when species invade from low abundances of 50 individuals. Additionally, based on their current abundances, only 8% of the species had an extinction risk greater than 5%. Our approach opens up new avenues for integrating observed spatial patterns with multiple ecological processes into mathematical theory. Our results demonstrate that emerging spatial patterns can contribute substantially to coexistence in species-rich forests, emphasizing the need to understand the interacting multiple processes under-pinning spatial patterns in greater detail than has previously been appreciated.

Tropical wet forest plants experience relatively stable temperatures throughout the year. However, tropical forests represent a mosaic of habitats characterized by different temperatures. Heat tolerances are expected to be adapted to temperatures specific to their habitats. Although heat tolerance of species sharing similar environments is expected to be similar, it is also possible that heat tolerance is constrained by evolutionary history because closely related species usually display similar physiologies. When exotic species are introduced to novel communities, colonization may be facilitated by their previous adaptation to high temperatures and other physiological, genetic and demographic traits, which may grant them some competitive advantage. Increasing temperatures may represent a strong environmental filter affecting community assembly, and higher heat tolerances could facilitate the persistence of exotic species in novel environments. Using a community of 32 native and 7 exotic Zingiberales species from different tropical habitats in Costa Rica, Central America, we aim to answer the following questions: (a) does evolutionary history constrain heat tolerance? (b) do plants in the same habitat display similar heat tolerances? (c) do the heat tolerances of exotic species differ from those of native species? We measured temperature‐dependent changes in photosynthetic fluorescence to determine the temperature at which the first sign of damage to photosystem II is observed (T15), and the temperature at which the fluorescence of photosystem II is reduced by 50% (T50). Using a community phylogeny, we tested for phylogenetic signal in T15 and T50. In addition, we tested for differences in heat tolerance among Zingiberales from old growth, secondary forests and open areas, as well as between native and exotic species. Our results support (a) a significant phylogenetic signal (Pagel's λ) for both T15 and T50, (b) communities from open areas displayed similar photosynthetic heat tolerance compared to species from old growth and secondary forests, and (c) exotic Zingiberales are marginally tolerant to high temperatures than native species, but only for T15. Our results suggest that evolutionary history constraints heat responses of native and exotic Zingiberales in a warming world. Read the free Plain Language Summary for this article on the Journal blog.

Premise: Hedychium J.Koenig (Zingiberaceae) is endemic to the Indo-Malayan Realm and is known for its colorful and fragrant flowers. Historically, two different pollination syndromes characterize Hedychium: diurnal or bird pollination and nocturnal or moth pollination. In this study we aim to understand the evolution of nocturnal and diurnal flowers, and to test its putative association with lineage diversification in Hedychium. Methods: A molecular tree of Hedychium was used as a scaffold upon which we estimated ancestral character-states, phylogenetic signals, and correlations for certain categorical and continuous floral traits. Further, we employed phylomorphospace and trait-dependent diversification rate estimation analyses to understand phenotypic evolution and associated lineage diversification in Hedychium. Results: Although floral color and size lacked any association with specific pollinators, white or pale flowers were most common in the early branching clades, when compared to bright-colored flowers which were more widely represented in the most derived clade IV. Five categorical and two continuous characters were identified to have informative evolutionary patterns which also emphasized that ecology may have played a critical role in the diversification of Hedychium. Conclusions: From our phylogenetic analyses and ecological observations, we conclude that specializations in pollinator interactions are rare in the hyperdiverse clade IV, thus challenging the role of both moth-specialization and bird-specialization as central factors in the diversification of Hedychium. However, our results also suggest that clade III (predominantly island clade) may show specializations, and future studies should investigate ecological and pollinator interactions, along with inclusion of new traits such as floral fragrance and anthesis time. This article is protected by copyright. All rights reserved.

The community of biologists has been eager to realize the promise of DNA barcodes since the concept of a rapid method for genetic identification of species was first proposed in 2003 [...]

Aim The relationships between biome shifts and global environmental changes in temperate zone habitats have been extensively explored; yet, the historical dynamics of taxa found in the tropical rain forest (TRF) remain poorly known. This study aims to reconstruct the relationships between tropical rain forest shifts and global environmental changes through the patterns of historical biogeography of a pantropical family of monocots, the Zingiberaceae. Location Global. Taxon Zingiberaceae. Methods We sampled DNA sequences (nrITS, trn K, trn L‐ trn F and psb A‐ trn H) from GenBank for 77% of the genera, including 30% of species, in the Zingiberaceae. Global fossil records of the Zingiberaceae were collected from literatures. Rates of speciation, extinction and diversification were estimated based on phylogenetic data and fossil records through methods implemented in BAMM. Ancestral ranges were estimated using single‐tree BioGeoBEARS and multiple‐trees BioGeoBEARS in RASP. Dispersal rate through time and dispersal rate among regions were calculated in R based on the result of ancestral estimation. Results The common ancestor of the Zingiberaceae likely originated in northern Africa during the mid‐Cretaceous, with later dispersal to the Asian tropics. Indo‐Burma, rather than Malesia, was likely a provenance of the common ancestor of Alpinioideae–Zingiberoideae. Several abrupt shifts of evolutionary rates from the Palaeocene were synchronized with sudden global environmental changes. Main conclusions Integrating phylogenetic patterns with fossil records suggests that the Zingiberaceae dispersed to Asia through drift of the Indian Plate from Africa in the late Palaeocene. Formation of island chains, land corridors and warming temperatures facilitated the emigration of the Zingiberaceae to a broad distribution across the tropics. Moreover, dramatic fluctuations of the speciation rate of Zingiberoideae appear to have been synchronized with global climate fluctuations. In general, the evolutionary history of the Zingiberaceae broadens our understanding of the association between TRF shifts in distribution and past global environmental changes, especially the origin of TRF in Southeast Asia.

DNA barcoding has transformed the fields of ecology, evolution, and conservation by providing a rapid and effective tool for species identification. The growth of DNA barcodes as a resource for biologists has followed advances in computational and sequencing technology that have enabled high-throughput barcoding applications. The global DNA barcode database is expanding to represent the diversity of species on Earth thanks to efforts by international consortia and expanding biological collections. Today, DNA barcoding is instrumental in advancing our understanding of how species evolve, how they interact, and how we can slow down their extirpation and extinction. This review focuses on current applications of DNA barcode sequences to address fundamental lines of research, as well as new and expanding applications of which DNA barcoding will play a central role.