71 



THE VEGETATION OF 'SWIDDENS' IN NORTH=EAST 

 YORKSHIRE. 



FRANK ELGEE, 

 Middleshrough. 



{Continued from page 20). 



This last-named Swidden passed into another, which was 

 practically grassed over with a turf of Agrosiis canina, Aira 

 praecox, and the Sheep's Fescue Grass {Fesiuca ovina), all 

 dwarfed and closely nibbled by sheep. Clumps of /. squarrosiis 

 were conspicuous in one part, and clumps of Call una in another. 

 Polytrichiim was also a constituent of this characteristic bit of 

 moorland sward. 



Sometimes large Swiddens which have been " graved " 

 for " turves," merely shew plants growing isolated here and 

 there, the rest of the ground being bare. One was noted near 

 the preceding examples, and the plants upon it were Poly- 

 trichiim, Agrostis, Aira, Juncus squarrosus, T'. Myrtillits, Poten- 

 tilla and Calluna. 



The following details of the plant life of a Swidden on a slope 

 facing the south are interesting. Towards the summit of the 

 slope the principal plants were Calluna, Aira praecox and 

 Juncus squarrosus. The latter species together with patches 

 of Agrostis, were very conspicuous on the slope itself, whilst 

 amongst the burnt stems of Heather at the foot of the Swidden, 

 Bilberry pre\'ailed with a few tufts of Polyirichum. 



On Swiddens of the mixed character, just described, Festuca 

 ovina is occasionally plentiful, and often occurs in rounded 

 tussocks closely bitten off by sheep. A Swidden shewing this 

 feature was observed on Fryup Ridge, where the ground was 

 practically covered with Fesiuca and Agrostis, both grasses 

 having a tendency to grow in old cart tracks ; young Heather 

 was also numerous with occasional plants of Juncus squarrosus 

 and Potentilla. This and the last described Swiddens were 

 surrounded by pure Calluna moors. Calluna frequently appears 

 first on tracks crossing Swiddens which may otherwise be desti- 

 tute of plants. 



We must next consider those Swiddens occurring on wet 

 ground, and one which was observed in Stockdale on a slope 



1910 Feb. I. 



