THIS DATASET HAS BEEN WITHDRAWN. This dataset includes all measurements of roots from the Climoor fieldsite in the Clocaenog Forest. The data spans three periods: 2003-2004, 2008 and 2011. In 2003 and 2004, 5cm x 15cm plastic root cores were measured, and roots manually picked out the soil. In 2008, root biomass was determined by sieving and washing. In 2011, root biomass, density and length was also determined using sieving and washing. However, the methods used in each of the periods differs so significantly the data should not be directly compared, only differences between experimental plots should be considered.
Publication date: 2014-03-07
In 2003 and 2004 root biomass was determined from soil cores that were cut from the soil using a combination of knife and driving a plastic corer (5cm x 15cm) down through the soil profile. Three replica cores were taken in each of the 9 experimental plots. The cores were transported back to the lab within the plastic core and stored at 4 degrees C until analysis. After the core was removed from the plastic corer, the length and weight of the core was measured. The organic soil horizon was then identified (it being visually more fibrous and less dense than the underlying inorganic layer) and the core was cut along this boundary. The organic soil horizon was measured and weighed, and then the roots were manually picked out of the soil by hand. The time used to pick roots out of the soil was limited to 5 minutes to ensure consistency. The same was repeated on the inorganic layer of the soil core (which was denser in nature and had far fewer roots), again a 5 minute limit was placed on manually picking out the roots. This method was repeated on cores taken in May 2013. Root biomass was measured in 2008 by extraction using a sieving and washing protocol. In 2008, soil cores 3cm diameter 20cm length were taken from the plots. The soil cores were removed from the corer at 5cm intervals (0-5 cm, 5-10 cm, 10-15 cm and 15-20 cm) and placed in plastic bags for transportation back to the laboratory where they were stored at 4 degrees C until extraction. Roots were extracted by first immersing sections of cores under 3cm of water for 15-30 minutes. Following this, the root/soil mass was gently broken up by hand underwater and the resulting mixture of water/soil/roots was poured into a sieve, which was agitated and further soil crumbs were broken up gently by hand. The water in the bowl was replaced 5 times for each core section. After this, the contents of the sieve were transferred into a clean container of water. Forceps were used to remove strands of roots. Roots were air-dried, then oven dried at 75 degrees C for three days. On 11/9/2011, root cores were taken using a stratified sampling technique from inside the experimental plots. In each plot, 3 cores (15cm length, 5cm diameter) were taken from underneath Calluna vulgaris. Cores were put in the freezer immediately upon return until required for analysis. During analysis, root cores were washed and roots extracted. Cores were sliced from the top into 1cm segments. 10cm of the cores was washed hence 0-1cm, 1-2cm, 2-3cm, data etc. Extraction was carried out using water in a sequential sieve block, once separated into different sizes roots were again suspended in water and manually extracted using tweezers. These were then scanned and analysed using Winrhizo software.