The colonial legacy of herbaria.

Herbarium collections shape our understanding of Earth's flora and are crucial for addressing global change issues. Their formation, however, is not free from sociopolitical issues of immediate relevance. Despite increasing efforts addressing issues of representation and colonialism in natural history collections, herbaria have received comparatively less attention. While it has been noted that the majority of plant specimens are housed in the Global North, the extent and magnitude of this disparity have not been quantified. Here we examine the colonial legacy of botanical collections, analysing 85,621,930 specimen records and assessing survey responses from 92 herbarium collections across 39 countries. We find an inverse relationship between where plant diversity exists in nature and where it is housed in herbaria. Such disparities persist across physical and digital realms despite overt colonialism ending over half a century ago. We emphasize the need for acknowledging the colonial history of herbarium collections and implementing a more equitable global paradigm for their collection, curation and use.

Walking on Visual Illusions.

In nature, sensory and physical characteristics of the environment tend to match; for example, a surface that looks bumpy is bumpy. In human-built environments, they often don't. Here, we report observations from people exploring if mismatch between visual and physical characteristics affected their perceived walking experience. Participants walked across four flat floors, each comprising of a visual illusion: two patterns perceived as alternating 3D "furrows and ridges," the Primrose Field illusion, and a variant of the Cafe Wall illusion as a control pattern without perceived 3D effects. Participants found all patterns intriguing to look at; some describing them as "playful" or "gentle." More than half found some of the patterns uncomfortable to walk on, aversive, affecting walking stability, and occasionally even evoking fear of falling. These experiences raise crucial research questions for the vision sciences into the impact of architectural design on well-being and walkability.

Impact of the COVID-19 nonpharmaceutical interventions on influenza and other respiratory viral infections in New Zealand.

Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats.

Impact of the COVID-19 nonpharmaceutical interventions on influenza and other respiratory viral infections in New Zealand.

Stringent nonpharmaceutical interventions (NPIs) such as lockdowns and border closures are not currently recommended for pandemic influenza control. New Zealand used these NPIs to eliminate coronavirus disease 2019 during its first wave. Using multiple surveillance systems, we observed a parallel and unprecedented reduction of influenza and other respiratory viral infections in 2020. This finding supports the use of these NPIs for controlling pandemic influenza and other severe respiratory viral threats.

Herbarium data: Global biodiversity and societal botanical needs for novel research.

Building on centuries of research based on herbarium specimens gathered through time and around the globe, a new era of discovery, synthesis, and prediction using digitized collections data has begun. This paper provides an overview of how aggregated, open access botanical and associated biological, environmental, and ecological data sets, from genes to the ecosystem, can be used to document the impacts of global change on communities, organisms, and society; predict future impacts; and help to drive the remediation of change. Advocacy for botanical collections and their expansion is needed, including ongoing digitization and online publishing. The addition of non-traditional digitized data fields, user annotation capability, and born-digital field data collection enables the rapid access of rich, digitally available data sets for research, education, informed decision-making, and other scholarly and creative activities. Researchers are receiving enormous benefits from data aggregators including the Global Biodiversity Information Facility (GBIF), Integrated Digitized Biocollections (iDigBio), the Atlas of Living Australia (ALA), and the Biodiversity Heritage Library (BHL), but effective collaboration around data infrastructures is needed when working with large and disparate data sets. Tools for data discovery, visualization, analysis, and skills training are increasingly important for inspiring novel research that improves the intrinsic value of physical and digital botanical collections.

Reduction in pain response by combined use of local lidocaine anesthesia and systemic ketoprofen in dairy calves dehorned by heat cauterization.

This study assessed the efficacy of ketoprofen for mitigating pain following dehorning with an electric cautery iron. Forty Holstein heifer calves, 4 to 8 wk of age, were randomized to receive a lidocaine cornual nerve block and either an injection of ketoprofen (3 mg/kg IM) or physiological saline, 10 min prior to dehorning. Cortisol was measured from serum obtained 10 min prior to dehorning and at 3 and 6 h post-dehorning. Calf behavior was video-recorded between 0 to 2, 3 to 5, and 6 to 8 h post-dehorning, and frequency of ear flicks, head shakes, head rubs, lying, standing, feeding, and grooming were recorded. Finally, 24-h intake of calf starter was recorded. There was no effect of treatment on cortisol (P > 0.1); however, ketoprofen-treated calves displayed less ear-flicks and total head behavior (P < 0.05), and tended to consume more starter (P = 0.09) than control calves. Ketoprofen is effective for mitigating behavioral effects of postsurgical pain following dehorning in 4- to 8-week-old calves.

Hawaiian native forest conserves water relative to timber plantation: species and stand traits influence water use.

Tropical forests are becoming increasingly alien-dominated through the establishment of timber plantations and secondary forests. Despite widespread recognition that afforestation results in increased evapotranspiration and lower catchment yields, little is known of the impacts of timber plantations on water balance relative to native forest. Native forest trees have been claimed to use water conservatively and enhance groundwater recharge relative to faster-growing alien species, and this argument should motivate native forest preservation and restoration. However, data have been available primarily for leaf-level gas exchange rather than for whole-plant and stand levels. We measured sap flow of dominant tree and tree fern species over eight weeks in native Metrosideros polymorpha forest and adjacent alien timber plantations on the island of Hawai'i and estimated total stand transpiration. Metrosideros polymorpha had the lowest values of sap flux density and whole-tree water use (200 kg m(-2) sapwood d(-1), or 8 kg/d for trees of 35 cm mean diameter at breast height, D), substantially less than timber species Eucalyptus saligna or Fraxinus uhdei (33 and 34 kg/d for trees of 73 and 30 cm mean D, respectively). At the stand level, E. saligna and F. uhdei trees had three- and ninefold higher water use, respectively, than native M. polymorpha trees. Understory Cibotium tree ferns were most abundant in M. polymorpha-dominated forest where they accounted for 70% of water use. Overall, F. uhdei plantation had the highest water use at 1.8 mm/d, more than twice that of either E. saligna plantation or M. polymorpha forest. Forest water use was influenced by species composition, stem density, tree size, sapwood allocation, and understory contributions. Transpiration varied strongly among forest types even within the same wet tropical climate, and in this case, native forest had strikingly conservative water use. Comparisons of vegetation cover in water use should provide additional resolution to ecosystem valuation and land management decisions.

Dynamics of transpiration, sap flow and use of stored water in tropical forest canopy trees.

In large trees, the daily onset of transpiration causes water to be withdrawn from internal storage compartments, resulting in lags between changes in transpiration and sap flow at the base of the tree. We measured time courses of sap flow, hydraulic resistance, plant water potential and stomatal resistance in co-occurring tropical forest canopy trees with trunk diameters ranging from 0.34-0.98 m, to determine how total daily water use and daily reliance on stored water scaled with size. We also examined the effects of scale and tree hydraulic properties on apparent time constants for changes in transpiration and water flow in response to fluctuating environmental variables. Time constants for water movement were estimated from whole-tree hydraulic resistance (R) and capacitance (C) using an electric circuit analogy, and from rates of change in water movement through intact trees. Total daily water use and reliance on stored water were strongly correlated with trunk diameter, independent of species. Although total daily withdrawal of water from internal storage increased with tree size, its relative contribution to the daily water budget (approximately 10%) remained constant. Net withdrawal of water from storage ceased when upper branch water potential corresponded to the sapwood water potential (Psi(sw)) at which further withdrawal of water from sapwood would have caused Psi(sw) to decline precipitously. Stomatal coordination of vapor and liquid phase resistances played a key role in limiting stored water use to a nearly constant fraction of total daily water use. Time constants for changes in transpiration, estimated as the product of whole- tree R and C, were similar among individuals (~0.53 h), indicating that R and C co-varied with tree size in an inverse manner. Similarly, time constants estimated from rates of change in crown and basal sap flux were nearly identical among individuals and therefore independent of tree size and species.

Axial and radial water transport and internal water storage in tropical forest canopy trees.

Heat and stable isotope tracers were used to study axial and radial water transport in relation to sapwood anatomical characteristics and internal water storage in four canopy tree species of a seasonally dry tropical forest in Panama. Anatomical characteristics of the wood and radial profiles of sap flow were measured at the base, upper trunk, and crown of a single individual of Anacardium excelsum, Ficus insipida, Schefflera morototoni, and Cordia alliodora during two consecutive dry seasons. Vessel lumen diameter and vessel density did not exhibit a consistent trend axially from the base of the stem to the base of the crown. However, lumen diameter decreased sharply from the base of the crown to the terminal branches. The ratio of vessel lumen area to sapwood cross-sectional area was consistently higher at the base of the crown than at the base of the trunk in A. excelsum, F. insipida and C. alliodora, but no axial trend was apparent in S. morototoni. Radial profiles of the preceding wood anatomical characteristics varied according to species and the height at which the wood samples were obtained. Radial profiles of sap flux density measured with thermal dissipation sensors of variable length near the base of the crown were highly correlated with radial profiles of specific hydraulic conductivity (k(s)) calculated from xylem anatomical characteristics. The relationship between sap flux density and k(s) was species-independent. Deuterium oxide (D(2)O) injected into the base of the trunk of the four study trees was detected in the water transpired from the upper crown after only 1 day in the 26-m-tall C. alliodora tree, 2 days in the 28-m-tall F. insipida tree, 3 days in the 38-m-tall A. excelsum tree, and 5 days in the 22-m-tall S. morototoni tree. Radial transport of injected D(2)O was detected in A. excelsum, F. insipida and S. morototoni, but not C. alliodora. The rate of axial D(2)O transport, a surrogate for maximum sap velocity, was positively correlated with the predicted sapwood k(s) and with tree height normalized by the relative diurnal water storage capacity. Residence times for the disappearance of the D(2)O tracer in transpired water ranged from 2 days in C. alliodora to 22 days in A. excelsum and were positively correlated with a normalized index of diurnal water storage capacity. Capacitive exchange of water between stem storage compartments and the transpiration stream thus had a profound influence on apparent rates of axial water transport, the magnitude of radial water movement, and the retention time in the tree of water taken up by the roots. The inverse relationship between internal water exchange capacity and k(s) was consistent with a trade-off contributing to stability of leaf water status through highly efficient water transport at one extreme and release of stored water at the other extreme.

Heat dissipation sensors of variable length for the measurement of sap flow in trees with deep sapwood.

Robust thermal dissipation sensors of variable length (3 to 30 cm) were developed to overcome limitations to the measurement of radial profiles of sap flow in large-diameter tropical trees with deep sapwood. The effective measuring length of the custom-made sensors was reduced to 1 cm at the tip of a thermally nonconducting shaft, thereby minimizing the influence of nonuniform sap flux density profiles across the sapwood. Sap flow was measured at different depths and circumferential positions in the trunks of four trees at the Parque Natural Metropolitano canopy crane site, Panama City, Republic of Panama. Sap flow was detected to a depth of 24 cm in the trunks of a 1-m-diameter Anacardium excelsum (Bertero & Balb. ex Kunth) Skeels tree and a 0.65-m-diameter Ficus insipida Willd. tree, and to depths of 7 cm in a 0.34-m-diameter Cordia alliodora (Ruiz & Pav.) Cham. trunk, and 17 cm in a 0.47-m-diameter Schefflera morototoni (Aubl.) Maguire, Steyerm. & Frodin trunk. Sap flux density was maximal in the outermost 4 cm of sapwood and declined with increasing sapwood depth. Considerable variation in sap flux density profiles was observed both within and among the trees. In S. morototoni, radial variation in sap flux density was associated with radial variation in wood properties, particularly vessel lumen area and distribution. High variability in radial and circumferential sap flux density resulted in large errors when measurements of sap flow at a single depth, or a single radial profile, were used to estimate whole-plant water use. Diurnal water use ranged from 750 kg H2O day-1 for A. excelsum to 37 kg H2O day-1 for C. alliodora.

Leaf orientation, light interception and stomatal conductance of Eucalyptus globulus ssp. globulus leaves.

Juvenile and adult leaves of the heteroblastic species Eucalyptus globulus Labill. ssp. globulus did not show active diurnal orientation toward or away from incident radiation. Juvenile leaves of a late-maturing sapling of a Tasmanian provenance were evenly distributed in all azimuth sectors. In contrast, an early-maturing sapling of the same age from Wilsons Promontory, Victoria had a predominance of adult leaf blades facing east and west. Mid-vein and blade angles of juvenile and adult leaves were non-random with an overall vertical declination of the leaves. Both leaf types intercepted a greater irradiance during the morning than at midday. Sub-horizontal juvenile leaves intercepted 22% more irradiance than vertical adult leaves during the middle of the day. The amphistomatal and isobilateral adult leaves intercepted sunlight equally on both leaf surfaces. Stomatal conductance was variable during the period of measurement but was similar for the Tasmanian juvenile (0.4 to 0.9 cm s(-1)) leaves and Wilsons Promontory adult (0.5 to 1.2 cm s(-1)) leaves. Greater light interception by the sub-horizontal juvenile leaves would confer a growth advantage to saplings and regenerating canopies. Reduced light interception and leaf temperature of vertical adult E. globulus leaves would assist in water conservation, particularly at high solar angles.