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

Cross-shelf circulation, zonation and maintenance mechanisms of Nyctiphanes capensis and Euphausia hanseni (Euphausiacea) in the northern Benguela upwelling system

31 pages, 9 figuresHorizontal and vertical cross-shelf distribution of developmental stages of the inshore euphausiid species Nyctiphanes capensis and the shelf-break species Euphausia hanseni during different phases of the upwelling cycle in the northern Benguela upwelling system are analysed, in order to provide an explanation for the consistent distribution patterns observed. A two-cell cross-shelf circulation model is proposed, based on upwelling in inshore areas as well as at the shelf break, probably reinforced by the possible existence of a strong equatorward current at the shelf break. It is concluded that both euphausiid species complete their entire life cycle within discrete zones across the shelf and slope regions. It was observed that the interaction of biological processes, especially ontogenetic migration, with the physical processes during different phases of the upwelling cycle resulted in differential probabilities of cross-shelf and alongshore transport by N. capensis and E. hanseni, and the mechanisms involved in the segregation and maintenance of the species in discrete zones of the northern Benguela upwelling system outlined. © 1992Peer Reviewe

Influence of the frontal system on the cross-shelf distribution of Euphausia lucens and Euphausia recurva (Euphausiacea) in the southern Benguela system

7 pages, 6 figuresThe distribution of the euphausiids Euphausia lucens and E. recurva along a transect of stations off the mouth of the Olifants River, on the west coast of South Africa, was investigated to examine interchange processes through the frontal system. Longshore currents dominated the study area and confirmed the existence of the shelf-break frontal system. Densities of E. lucens larvae and adults declined sharply seawards of the front, whereas E. recurva were distributed farther offshore at the outer margin of the front. The front allowed little net cross-shelf transport of euphausiid reproductive products and maintained the species discreteness of the two euphausiids. © 1991 Taylor & Francis Group, LLC

Major pelagic borders of the Benguela upwelling system according to euphausiid species distribution

15 pages, 9 figuresThe distribution patterns of 21 species of euphausiids collected during eight research cruises extending from 17°30′ to 32°30′S and offshore to 135 miles were studied by means of Principal Component Analysis. The existence of possible environmental borders for zooplankton populations was explored and discussed in relation to the main hydrographic features of the Benguela upwelling system. Three main boundaries were identified: the shelf-break zone; the area between 19 and 20°S; and the northernmost extension of the Lüderitz upwelling cell (24°30′S). The first boundary separates inshore and shelf species from shelf-break and oceanic species, revealing the boundary between shelf and oceanic circulation. It is reinforced by the strong equatorward and poleward flows that occur over the shelf-break at different depths. The boundary at 19–20°S was related to the general surface, wind-driven flow of the Benguela and its interaction with the Angola Current. Knowledge of the temporal variability associated with this boundary may well be enhanced by monitoring the extension of the proposed indicator species, Euphausia americana and E. gibboides. The turbulent regime associated with the perennial activity of the Lüderitz upwelling cell defines the third main boundary zone. It partially separates inshore species of the northern and southern Benguela and reflects the relative dominance of cross-shelf or alongshore currentsPeer reviewe

Estimates of standing stock, production and consumption of meso- and macrozooplankton in the Benguela ecosystem

Attempts are made to consolidate current information on estimates of standing stock, production and consumption of meso- and macrozooplankton from the shelf region of the west and south coasts of southern Africa for inclusion in a network analysis of carbon flow in the Benguela system. The meso- and macrozooplankton communities consist chiefly of copepods and euphausiids respectively. Although geographic and seasonal differences in standing stock are reasonably well described for the inner shelf (<200 m), knowledge of production and rate processes affecting standing stock is limited, and extrapolation to the whole shelf area (<500 m) provides only a crude appraisal of the real situation. Despite the uncertainties, direct measurements have improved on estimates previously inferred. It seems likely that grazing by meso- and macrozooplankton plays a minor role in phytoplankton losses in the Benguela system. However, it would appear that predation by macrozooplankton, particularly under swarming conditions, has an appreciable impact on mesozooplankton biomass

Vertical migration and feeding of Euphausia lucens (Euphausiacea) in the Southern Benguela

25 pages, 9 figures, 2 tablesDiel migration and feeding were examined for populations of Euphausia lucens living in the near- and offshore waters of the southern Benguela. Euphausiids at both stations displayed nocturnal diel vertical migration patterns. Animals inshore ascended in a slow-fast-slow manner which seems to be related to differential food concentrations throughout the water column Pronounced quantitative and qualitative changes in the diet of E.lucens were observed offshore but not inshore. These differences are discussed in relation to different ambient food environments © 1991 Oxford University PressPeer Reviewe

Vertical migration and feeding of Euphausia lucens (Euphausiacea) in the Southern Benguela

25 pages, 9 figures, 2 tablesDiel migration and feeding were examined for populations of Euphausia lucens living in the near- and offshore waters of the southern Benguela. Euphausiids at both stations displayed nocturnal diel vertical migration patterns. Animals inshore ascended in a slow-fast-slow manner which seems to be related to differential food concentrations throughout the water column Pronounced quantitative and qualitative changes in the diet of E.lucens were observed offshore but not inshore. These differences are discussed in relation to different ambient food environments © 1991 Oxford University PressPeer Reviewe

Community structure and trophic ecology of euphausiids in the Benguela ecosystem

17 pages, 9 figures, 2 tablesCurrent knowledge of the community structure, life history strategies and trophodynamics of euphausiids in the Benguela ecosystem is synthesized. Three species dominate, Euphausia lucens over the shelf region of the southern Benguela, Euphausia hanseni over the outer shelf off Namibia and Nyctiphanes capensis in the neritic and shelf regions of the northern Benguela. Various models of interactions between biological processes and physical features are considered to explain likely mechanisms whereby these species can remain spatially segregated. All three species breed throughout the year, produce multiple broods and large numbers of eggs per brood and have high turnover rates. These strategies enable them to maintain high production in terms of both somatic growth and reproductive output throughout the year. Biomass of euphausiids in the northern Benguela is about double that of the west coast of the southern Benguela, consistent with similar geographical differences in phytoplankton abundance. Adult euphausiids are opportunistic omnivores and the larval stages are primarily herbivorous. Alternative feeding patterns are reflected in differences in the vertical migratory behaviour of various ontogenetic stages and ambient food type. Factors causing a switch from herbivory to carnivory are considered. Grazing of euphausiids is considered to play a minor role in phytoplankton losses, but euphausiids could exert considerable predatory impact on mesozooplankton and therefore compete directly with pelagic fish. Combined predation by various fish species has an appreciable impact on euphausiid production. © 1992 Taylor & Francis Group, LLC