scholarly journals Tree Fern Apical Temperatures at the Royal Botanic Garden Edinburgh

Author(s):  
Alastair Wardlaw ◽  
Louise Galloway ◽  
Andrew Ensoll

Tree ferns are difficult to maintain out of doors in the British Isles except in western localities, where winter temperatures are moderated by the North Atlantic Drift, or in places where buildings provide a clement microclimate. The present study of tree-fern apical temperatures during winter was carried out on five trunked specimens of Dicksonia antarctica that had been grown satisfactorily out of doors for several years, while planted in the ground of a courtyard at the Royal Botanic Garden Edinburgh (RBGE). The plants were never wrapped or otherwise protected with thermal insulation during the winter months. An electric thermometer was inserted into the apical cleft of each plant in November 2003, and weekly readings of minimum and maximum temperature taken until April 2004. The ambient temperature of the air in the courtyard was similarly recorded and compared with the screen and grass temperatures at the RBGE weather station in the main botanic garden. The lowest grass and screen temperatures were respectively -11.2°C and -7.1°C, whereas the lowest courtyard and fern-apical temperatures were respectively -3.2°C and -0.8°C. Thus in the coldest period of that winter there was over 10°C difference in temperature between ground level in the main garden and a tree fern apical cleft in the sheltered courtyard. The tree ferns were not noticeably damaged by exposure of the apical cleft region to just below freezing point on a few occasions and the fronds stayed green. The five individual plants differed considerably in trunk height, diameter and volume. Regression analysis revealed that there was a significantly increasing thermal-insulating effect in the apical cleft associated with larger trunk diameters and volumes. The RBGE weather station temperatures during the winter of 2003-4 were unexceptional when compared with records from the previous 19 years. Thus the data from 2003-4 may be taken as representing a typical recent winter for this Edinburgh location. This study highlights the benefits of having detailed temperature measurements when assessing the winter-protective capabilities of a particular micro—environment for a semi-hardy species such as D. antarctica.

Author(s):  
Andrew Ensoll ◽  
Louise Galloway ◽  
Alastair Wardlaw

Ten plants of six species of tree fern were trialled for frost hardiness during the winter of 2005/06 when they were planted outdoors in the ground of an interior courtyard at the Royal Botanic Garden Edinburgh. The species were Culcita macrocarpa, Cyathea dealbata, Cyathea dregei,Cyathea smithii, Dicksonia antarctica and Thyrsopteris elegans. An additional specimen of C. dregei was planted in the main garden. The apex region of each tree fern was fitted with an electric thermometer probe to record weekly minimum and maximum temperatures. These were compared with the air temperatures of the courtyard. For thermal insulation, the trunks and crowns of the three Cyathea species were encased in straw. The prostrate rhizomes of C. macrocarpa and T. elegans were covered respectively with leaf litter, straw and a polystyrene tile. As comparators, three trunked specimens of D. antarctica were given no winter wrapping, since previous experience had shown it to be unnecessary. All ten plants survived the winter of 2005/06 which was colder than average, and put out new growth the following spring. Fronds of D. antarctica and C. macrocarpa stayed green; the fronds of the other species were withered by the coldest exposures when the air temperature reached 4.7°C.Compared with the main botanic garden, the courtyard provided a relatively mild microclimate. It was on average 2.5 °C warmer than the air temperature measured in the screen of the main garden weather station, and 7.7°C warmer than the ‘grass’ temperature in the main garden, which went down to –13°C at its lowest. All tree fern apices registered sub-zero temperatures, the range in different plants being from –0.3 to –3.4°C. The apex regions did not get as cold as the surrounding air temperature, which ranged between 0.5 and 2.3°C. The three D. antarctica (without added insulation) had minimum apical temperatures in the same range as the species that were wrapped for the winter. The insulation effect in the apex regions was also shown by the weekly maximum temperatures, which on average were lower than those of the courtyard air maxima.In conclusion, the combination of the locally favourable microclimate of the courtyard, plus appropriate trunk and crown insulation provided for some species, allowed the planting outdoors, of tree ferns normally grown in Edinburgh under heated glass.


2015 ◽  
Vol 42 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. G. Ayres

Isaac Bayley Balfour was a systematist specializing in Sino-Himalayan plants. He enjoyed a long and exceptionally distinguished academic career yet he was knighted, in 1920, “for services in connection with the war”. Together with an Edinburgh surgeon, Charles Cathcart, he had discovered in 1914 something well known to German doctors; dried Sphagnum (bog moss) makes highly absorptive, antiseptic wound dressings. Balfour directed the expertise and resources of the Royal Botanic Garden, Edinburgh (of which he was Keeper), towards the identification of the most useful Sphagnum species in Britain and the production of leaflets telling collectors where to find the moss in Scotland. By 1918 over one million such dressings were used by British hospitals each month. Cathcart's Edinburgh organisation, which received moss before making it into dressings, proved a working model soon adopted in Ireland, and later in both Canada and the United States.


Author(s):  
Natacha Frachon ◽  
Martin Gardner ◽  
David Rae

Botanic gardens, with their large holdings of living plants collected from around the world, are important guardians of plant biodiversity, but acquiring and curating these genetic resources is enormously expensive. For these reasons it is crucial that botanic gardens document and curate their collections in order to gain the greatest benefit from the plants in their care. Great priority is given to making detailed field notes and the process of documentation is often continued during the plants formative years when being propagated. However, for the large majority of plants this process often stops once the material is planted in its final garden location. The Data Capture Project at the Royal Botanic Garden Edinburgh is an attempt to document specific aspects of the plant collections so that the information captured can be of use to the research community even after the plants have died.


Author(s):  
An Zhang ◽  
Jinhuang Lin ◽  
Wenhui Chen ◽  
Mingshui Lin ◽  
Chengcheng Lei

Long-term exposure to ozone pollution will cause severe threats to residents’ physical and mental health. Ground-level ozone is the most severe air pollutant in China’s Pearl River Delta Metropolitan Region (PRD). It is of great significance to accurately reveal the spatial–temporal distribution characteristics of ozone pollution exposure patterns. We used the daily maximum 8-h ozone concentration data from PRD’s 55 air quality monitoring stations in 2015 as input data. We used six models of STK and ordinary kriging (OK) for the simulation of ozone concentration. Then we chose a better ozone pollution prediction model to reveal the ozone exposure characteristics of the PRD in 2015. The results show that the Bilonick model (BM) model had the highest simulation precision for ozone in the six models for spatial–temporal kriging (STK) interpolation, and the STK model’s simulation prediction results are significantly better than the OK model. The annual average ozone concentrations in the PRD during 2015 showed a high spatial variation in the north and east and low in the south and west. Ozone concentrations were relatively high in summer and autumn and low in winter and spring. The center of gravity of ozone concentrations tended to migrate to the north and west before moving to the south and then finally migrating to the east. The ozone’s spatial autocorrelation was significant and showed a significant positive correlation, mainly showing high-high clustering and low-low clustering. The type of clustering undergoes temporal migration and conversion over the four seasons, with spatial autocorrelation during winter the most significant.


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