Little has been written about the substrates selected by newts on land, but observations from Cuxton Chalk pit in Strood, Kent showed some quite remarkable and very surprising associations.
Over 20,000 Smooth newts of all ages were moved as part of a licensed development. This involved extensive use of drift fencing/pitfalling, direct searching, followed by a painstaking destructive clearance. It was in the latter phase that it became apparent that Smooth Newt efts were positively attracted to the drier substrates. The high chalk cliffs that surrounded the pit eroded to form extensive talus slopes of loose friable chalk rubble from golf ball to pea size. These were partly shaded by birch dominated scrub/young woodland. It was within this debris that one year old Smooth Newt efts were most abundant. They were clearly uniquely able to survive here where there was no possible connection to ground water moisture, often 2-3m up in the screes. Adult Smooth and Great Crested Newt adults and efts were found mainly under debris which was lying on ground connected by capillary action to the wildly fluctuating groundwater levels in this bizarre pit. A huge pile of clayey overburden was present but rarely used by any newts, showing that there is a limit to drought tolerance. When I first visited the site I had assumed the newts would be concentrated in the extensive mossy covered fen areas in the lowest parts of the pit (but except when breeding in these when flooded), newts were extremely rare in this area. In high summer the moss shrivelled and presumably would have had a desiccating effect on any amphibians within it.
In hindsight i wish I had done more science, but the sheer abundance of amphibians was such that it was a full time task just rescuing them!