TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Nonrandom extinction leads to elevated loss of angiosperm evolutionary history

The phylogenetic clustering of extinction may jeopardize the existence of entire families and genera, which can result in elevated reductions of evolutionary history (EH), trait diversity, and ecosystem functioning. Analyses of globally threatened birds and mammals suggest current extinction threats will result in a much higher loss of EH than random extinction scenarios, while the analyses of the taxonomical distribution of regionally rare plants find the opposite pattern. The disproportionately high number of rare plant species within species-rich families potentially suggests that lower losses of plant EH will be sustained than expected under random extinction. We show that at a global scale, this is not the case. Species-poor (especially monotypic) angiosperm families are more often at risk of extinction than expected. Because these high-risk species-poor families are as evolutionarily distinct as other families, the expected family-level EH plausibly lost in the next 100 years exceeds that predicted from random extinction by up to ~1165 million years.Centre of Excellence for Invasion Biolog

Is reproduction of endemic plant species particularly pollen limited in biodiversity hotspots?

Current evidence suggests that plants in biodiversity hotspots suffer more from pollen limitation of reproduction than those in lower diversity regions, primarily due to the response of self-incompatible species. Species in biodiversity hotspots may thus be more at risk of limited reproduction and subsequent population decline. Should these species have restricted ranges (i.e. be endemics to a certain region), pollen limitation within highly diverse regions may pose an important threat to global plant biodiversity. We further dissect the global pattern by exploring whether pollen limitation of range-restricted (endemic) species is distinctive and/or relates differently to species diversity than that of widespread (non-endemic) species. To provide a preliminary test of this prediction we conducted both cross-species and comparative phylogenetic meta-analyses to determine the effect of endemism on the magnitude of pollen limitation and its relationship with regional species richness. Our data set included 287 plant species belonging to 78 families distributed world-wide. Our results revealed that endemism and self-compatibility contribute to the global association between pollen limitation and species richness. Self-incompatible species were more pollen limited than self-compatible ones, and the PICs analysis indicated that transitions to endemism were associated with transitions to self-compatibility. The relationship between pollen limitation and species richness was significant only for the self-incompatible species, and was monotonically increasing in non-endemic species but accelerating in the endemic species. Thus, self-incompatible endemic species from biodiversity hotspots are at the greatest risk of pollination failure, a previously unknown aspect suggesting this group of species as a top priority for future development of conservation strategies. In contrast, reproduction of self-compatible species appears to be unrelated to plant diversity, although we caution that current data do not account for the reproductive limitation due to the quality of pollen received. Understanding the mechanisms underlying these patterns requires further investigation into plant-plant pollinator mediated interactions and the dynamics of pollen transfer in communities differing in species diversity. © 2009 The Authors.Peer Reviewe

The importance of marginal population hotspots of cold-adapted species for research on climate change and conservation

Areas hosting hotspots of low-latitude marginal populations of cold-adapted plant species could be key areas for understanding geographical attributes that result in refugia during climatic shifts as well as the conservation of genetic diversity in the face of climate change. Low-latitude populations of cold-adapted plants are important because they may harbour the combination of alleles that foster persistence in a warmer climate. Consequently, identification of areas where arctic-alpine, circumpolar and circumboreal species reach the low-latitude ends of their distribution will present a unique opportunity to uncover processes that shaped current biogeographical patterns, as well as prepare for future scenarios. Here, we identify 35 main marginal population hotspots (19 and 16 areas in North America and Europe, respectively) of 183 plant taxa. These hotspots represent areas where southern marginal populations of cold-adapted species co-occur. The identification of hotspots was based on geographic overlap of southernmost locations of the target species, in a 50\ua0 7\ua050\ua0km grid. With a threshold of two species in a single grid cell or in two contiguous cells, the analysis revealed that hotspots are in most cases located in the southern portion of major mountain chains. However, hotspots also occur in lowland areas at high latitudes (Fennoscandia, Alaska, Hudson Bay) which do not necessarily correspond to known cold- or warm-stage refugia (e.g. Alps). Rockies and Sierra Nevada both in California and Spain, Apennines, and the southern Scandes, maintain their hotspot status even with more stringent cut-off thresholds (>3 and >5 species per cell group). From a conservation point of view, our analysis reveals that only a small portion of the hotspots are currently included within protected areas. We discuss the importance of marginal population hotspots to future research on climate change and, finally, outline how conservation strategies can capitalize on the knowledge gained from studying climate change effects on cold-adapted plants

Plant diversity in the human diet: weak phylogenetic signal indicates breadth

Worldwide, humans have access to a greater range of food plants than does any other species. Examination of phylogenetic patterns in plants consumed by animals has recently uncovered important ecological processes. The same techniques, however, have not been applied to our own species. Here we show that although humans tend to eat more species in certain families (e.g., Rosaceae) and fewer in others (e.g., Orchidaceae), the proportion of edible species in most families is similar to random expectations. Phylogenetic patterning in angiosperm edibility is also weak. We argue that the remarkable breadth of the human diet is the result of humans’ huge geographic range, diverse food-collection methods, and ability to process normally inedible items. Humans are thus generalist feeders in the broadest sense. Cross-cultural analyses of diversity in the plant diet of humans could represent a fascinating new field of research linking ecology, anthropology, history, and sociology.Centre of Excellence for Invasion Biolog

The summary data for a review of the relationship with pollen limitation of plant reproduction

<p>Recent work on the ecosystem service of biodiversity suggests that higher pollinator diversity could lower pollen limitation, but these two aspects of plant–pollinator communities have only rarely been causally connected. Here we present a review of studies that produced quantitative assessments of both pollinator diversity and evenness as well as pollen limita- tion of focal plant species. Although pollen limitation is expected to be lower when pollinator diversity is high, our analysis suggests this relationship is weak. The relationship may be obscured when features of the plant species (e.g., average level of specialization) are confounded with features of the plant communities (e.g., habitat). We encourage researchers investigat- ing pollen limitation to consider including measures of diversity of the floral visitors, and their effectiveness. These data would permit a more powerful test of the relationships among these variables and improve our understanding of the critical elements of stable plant–pollinator networks.</p

The scope of Baker's law.

Baker's law refers to the tendency for species that establish on islands by long-distance dispersal to show an increased capacity for self-fertilization because of the advantage of self-compatibility when colonizing new habitat. Despite its intuitive appeal and broad empirical support, it has received substantial criticism over the years since it was proclaimed in the 1950s, not least because it seemed to be contradicted by the high frequency of dioecy on islands. Recent theoretical work has again questioned the generality and scope of Baker's law. Here, we attempt to discern where the idea is useful to apply and where it is not. We conclude that several of the perceived problems with Baker's law fall away when a narrower perspective is adopted on how it should be circumscribed. We emphasize that Baker's law should be read in terms of an enrichment of a capacity for uniparental reproduction in colonizing situations, rather than of high selfing rates. We suggest that Baker's law might be tested in four different contexts, which set the breadth of its scope: the colonization of oceanic islands, metapopulation dynamics with recurrent colonization, range expansions with recurrent colonization, and colonization through species invasions

Sexual ratio and floral biology of the dioecious Neea theifera Oerst. (Nyctaginaceae) in a cerrado rupestre of central Brazil Razão sexual e biologia floral de Neea theifera Oerst. (Nyctaginaceae), uma espécie dióica na vegetação de um cerrado rupestre no Brasil Central

Dioecy is characterized by a complete separation of sexual functions on male and female plants. It has evolved many times in flowering plants and is widespread among distinct Angiosperm families. It is viewed as a reproductive strategy to reduce endogamy, and to promote optimal resource allocation between male and female sexual functions. Neea theifera is a common species in Cerrado, neotropical savannas in Brazil, but information regarding its reproductive biology is still incomplete. In order to investigate how environmental conditions possibly affect this dioecious species, we studied its floral biology, sex ratio and spatial distribution of sexual morphs along a soil-altitudinal gradient. The sex ratio did not significantly deviate from the expected 1:1 ratio. However, flower abundance in the population was significantly biased towards staminate flowers. Female individuals were larger than male individuals and plant size was negatively correlated with altitude, but did not differ between sexual morphs. The population did not show spatial segregation of sexes and male individuals were sexually mature earlier than female ones. Staminate flowers were larger than pistillate flowers and presented high pollen viability. Meliponini bees, small flies and thrips were potential pollinators, but pollination success was very low. Dioecy in N. theifera corroborates many general features of this reproductive strategy, such as woody habit, inconspicuous flowers, pollination by small generalist insects and differential resource allocation between male and female plants. However, reproduction in this species seems to be impaired by pollinator limitation. The results showed that the soil-altitude gradient influenced the growth pattern of the species and may play an important role in its reproductive biology but did not affect dioecy directly.<br>Dioicia é caracterizada pela separação completa das funções sexuais, na qual plantas apresentam indivíduos masculinos e femininos. Este sistema evoluiu muitas vezes entre as Angiospermas e está amplamente distribuído entre as distintas famílias. É visto como uma estratégia reprodutiva para reduzir a endogamia e otimizar a alocação diferencial de recursos entre as funções sexuais masculinas e femininas. Neea theifera é uma espécie comum no Cerrado, área de Savana Neotropical no Brasil, mas informações acerca de sua biologia reprodutiva são incompletas. Para investigar se as condições ambientais afetam espécies dióicas, foi estudada sua biologia floral, a razão sexual e distribuição espacial dos morfos ao longo de um gradiente de solo-altitude. A razão sexual da população não diferiu da razão esperada de 1:1. Porém, a abundância de flores estaminadas na população foi significativamente maior. Os indivíduos femininos foram maiores que os masculinos e o tamanho das plantas correlacionou-se negativamente com a altitude, apesar de não diferirem entre os morfos sexuais. A população não apresentou segregação espacial dos morfos sexuais e os indivíduos masculinos apresentam maturação sexual precoce em relação aos femininos. Flores estaminadas foram maiores que as pistiladas, além de apresentarem alta viabilidade polínica. Abelhas Meliponini, pequenas moscas e tripes foram os potenciais polinizadores, entretanto o sucesso de polinização foi muito baixo. A dioicia em N. theifera corrobora muitas características gerais desta estratégia reprodutiva, como hábito lenhoso, flores inconspícuas, polinização por pequenos insetos generalistas e alocação diferencial de recursos entre indivíduos masculinos e femininos. Porém, a reprodução nesta espécie é aparentemente afetada por limitação de polinizadores. Os resultados mostram que o gradiente de solo-altitude influencia o padrão de crescimento da espécie e pode ter um importante papel na biologia reprodutiva da planta, mas não afeta diretamente a dioicia