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

Cretaceous oblique extensional deformation and magma accumulation in the Fosdick Mountains migmatite-cored gneiss dome, West Antarctica

The Fosdick Mountains, West Antarctica, expose a 15 x 80 km migmatite-cored gneiss dome consisting of migmatitic gneisses, diatexite migmatite, and subhorizontal leucogranite sheets. The Fosdick dome was emplaced and exhumed in the mid-Cretaceous due to oblique extension associated with the West Antarctic Rift system along the West Antarctic-New Zealand segment of East Gondwana. The dome is bounded to the south by a dextral oblique detachment structure and to the north by an inferred dextral strike-slip fault. Within the Fosdick dome and in the detachment zone, granite occupies leucosomes, dikes, sills, and dilatant and shear structures. The pattern of kilometer-scale domains of migmatite and granite suggest that lithologic variations and heterogeneous deformation (boudinage) resulted in pressure gradients that enhanced melt flow and magma accumulation in the Fosdick dome. Steep foliations are overprinted, folded, and transposed by subhorizontal fabrics. The crosscutting relationship is interpreted as a transition from wrench deformation to oblique divergence. Steep structures in the dome host concordant, subvertical leucosome and granite sheets yielding SHRIMP U-Pb zircon ages between ca. 117 and 114 Ma. Prevalent subhorizontal domains host large volumes of subhorizontal diatexite migmatite and granite sheets that yield U-Pb zircon ages between ca. 109 and 102 Ma. These ages indicate a timescale for melt influx of approximately 15 Ma and that the transition from wrench to oblique divergence may have occurred in as little as 5 Ma. Granites with crystallization ages between ca. 109 and 102 Ma were also emplaced in the South Fosdick Detachment zone, indicating that the detachment was active during oblique divergence. SHRIMP U-Pb titanite ages between ca. 102 and 97 Ma for late- to post-tectonic diorite dikes are interpreted as emplacement ages and give a minimum age for gneissic foliation development during detachment faulting. The Fosdick Mountains preserve a record of the middle to lower crustal response to a transition from wrench to oblique extensional deformation. Overprinting structural relationships show that a change in the angle of oblique extension can induce accumulation of subhorizontal magma sheets and lead to initiation of a detachment zone

Oblique dilation, melt transfer, and gneiss dome emplacement

The upward transfer of partially molten crust and the formation of gneiss domes and metamorphic core complexes commonly take place by localization of normal or oblique extension in the middle and upper crust. In Marie Byrd Land, Antarctica, a transition from wrench to oblique extension occurred during oblique plate divergence along the East Gondwana margin and intracontinental crustal extension associated with the West Antarctic Rift System in mid-Cretaceous time. Migmatites in the Fosdick dome record steep fabrics formed during wrenching, and associated granite networks display crystallization ages of 117-115 Ma. These steep fabrics are overprinted by subhorizontal foliation and leucogranite sheets with crystallization ages in the 109-102 Ma range. Syntectonic emplacement of granite sheets in the South Fosdick detachment zone indicates that detachment tectonics led to rapid exhumation of the terrain by 100 Ma. This study has implications for understanding melt transport, magma accumulation, and the formation of detachments in an oblique tectonic setting

Reproductive biology of the Antarctic “sea pen” Malacobelemnon daytoni (Octocorallia, Pennatulacea, Kophobelemnidae)

The reproductive biology of the sea pen Malacobelemnon daytoni was studied at Potter Cove, South Shetland Islands, where it is one of the dominant species in shallow waters. Specimens collected at 15–22 m depth were examined by histological analysis. M. daytoni is gonochoristic and exhibited a sex ratio of 1:1. Oocyte sizes (>300 µm) and the absence of embryos or newly developed larvae in the colonies suggest that this species can have lecithotrophic larvae and experience external fertilization. This life strategy is in line with other members of the group and supports the hypothesis that this could be a phylogenetically fixed trait for pennatulids. It was observed that oocytes were generated by gastrodermic tissue and released to the longitudinal canal. Thereafter, they migrate along the canal until they reach maturity and are released by autozooids at the top of the colonies. This striking feature has not yet been reported for other pennatulaceans. Mature oocytes were observed from colonies of 15 mm in length, suggesting that sexual maturity can be reached rapidly. This is contrary to what is hypothesized for the vast majority of Antarctic benthic invertebrates, namely that rates of activities associated with development, reproduction and growth are almost universally very slow. This strategy may also explain the ecological success of M. daytoni in areas with high ice impact as in the shallow waters of Potter Cove