England english field forest fresh grass Great Britain green hills landscape meadow natural nature rural sky South Downs spring Sussex trees woodland banks Bedfordshire course flow great Ouse oxygenate oxygenation reflections river water waterweed weir blue bluebell carpet Castanea chestnut coppice Endymion non-scriptum flower leaf leaves sunlight tree trunk wild wood young bridleway countryside exercise lane road track travel walk farm hedge home house peace quiet background border colors copy copyspace day design desktop fields garden gardening grassy green grass holiday isolation lawn plants summer summers day warm avenue bright lime linden path Tilia trunks