“Differential responses among species may cause problems for life cycles such as pollinating insects emerging out of synchrony with flowers opening in spring,” he said. “This could increase vulnerability to extreme events such as late frosts, disrupt food webs, and change the balance of competition between species.”

The full article can be read here: https://www.heraldscotland.com/news/15166462.revealed-why-spring-is-coming-earlier-and-earlier-each-year/  

RBGE records from 1977 – 2014 show that temperatures have been gradually increasing.  For example, the trend for air frosts over the past years has been negative with, on average, one less frosty day every three years (-0.35 days/year).  Ground frosts, measured by the grass temperature, have also shown a downward trend with a reduction of -0.54 days/year (max. 161 days in 1979, min. 72 days in 2014) when the ground was frozen.  The graph below illustrates the number of days with average air temperatures above 15°C (illustrated with a yellow line) and days below 5°C (illustrated with a blue line).

As can be seen with the two red lines, there is a general trend of decreasing cold days and an increase in the number of warm days from 1977 till 2014.  

Signs of climate change including longer drought have been reported in Scotland.  Last year in the Spey Valley reported unusually dry conditions leading to a shortage of grass for silage due to several weeks without significant rainfall and soaring temperatures (BBC, 2018).  Last year, Scotland experienced its warmest day in June in more than 20 years at 31°C in Aviemore (western Scotland) on the 27^th.  This was quickly followed the next day (28^th June 2018) by 33.2°C in Motherwell which was noted as Scotland’s highest ever temperature since records began.    

According to Tony Garn, Garden Supervisor at RBGE: “We have a changing climate.  The long term trend over the past forty years shows a steady increase in total rainfall; heavy rainfall events are becoming more frequent and intense, leading to more waterlogging, runoff and flooding.  For example, the total rainfall for July 2018 was 32.8mm and the sunshine total was 229.4 hours.  By way of contrast, in 2012 we had 181.6mm of rain and 105 hours of sunshine.  Last year, we had the driest summer since 1976.”    

These changes in weather patterns have a knock on effect for plant communities.  According to Ruth Monfries, a Climate Scientist at RBGE: “All regions of Scotland have seen an increase in the growing season of more than five weeks since 1961.  Our weather has always been changeable but climate change is bringing more extremes and unseasonal events that are hard to plan for.  Climate change for Scotland is not a gradual warming but is characterised by weirding of the weather.”

Although less popular for decorating, native Scots Pine (Pinus sylvestris) is also available as a Christmas tree. 

While it doesn’t seem to be mentioned on the Earth’s Endangered Creature’s list, there is a third Sorbus species endemic to Arran – the Catacol Whitebeam (S. pseudomeinichii).  The Catacol Whitebeam is represented by only a single tree.  This tree is situated precariously on the side of a steep ravine and its immediate danger is the threat of being washed downstream in a heavy storm.

“On the Causes of Plants” discusses the cultivation of plants – optimal growing conditions etc. along with their practical applications and economic value.  

Both treatises were of vast importance during the Middle Ages as they constituted the first systemisation of the botanical world.

Text can be read here:    https://www.loebclassics.com/view/LCL070/1916/volume.xml