The impact of red deer management on cryptogam ecology in vegetation typical of north west Scotland

Abstract

Background: An understanding of the effects of red deer on bryophyte and lichen communities in wet heath and bog vegetation typical of northwest Scotland is important so that land managers can make more informed decisions concerning deer numbers. Aims: To compare various measures of cryptogam species diversity inside and outside a number of established deer exclosures at the Letterewe and Little Gruinard estates, Wester Ross, Scotland. Methods: Species cover data were recorded from 192 2 m × 2 m quadrats allocated to 32 blocks and assigned to nine exclosures of different ages with due attention to randomisation. Linear mixed effects models were fitted to the data. Results: In the short to medium term there was no significant difference in cryptogam dominance, diversity and species richness on either side of the exclosures. However, Cladonia lichens responded to a lack of trampling and were significantly more abundant inside exclosures. Greater Calluna vulgaris cover in the absence of a large herbivore is likely to have created conditions that promote the growth of Sphagnum capillifolium ssp. rubellum and this in turn increased the habitat available for several liverworts. Conclusions: The upper limit of deer numbers deemed appropriate for reducing loss of Calluna cover in wet heath vegetation is set too high to prevent impact on important cryptogam communities.

Effects of rotational prescribed burning and sheep grazing on moorland plant communities: Results from a 60‐year intervention experiment

“…Conversely, the lack of response to light in the least disturbed (N) treatment suggests that the dense canopy cover is restricting species with greater light requirements. This is in keeping with the responses about individual species noted earlier, and especially the bryophyte and lichen responses (Burch, ; Harris et al, ; Moore & Crawley, ; Moore & Crawley, ,b; Virtanen & Crawley, ).…”

“…In this study, where grazing pressure was reduced, C. vulgaris as well as S. capillifolium ssp. rubellum , five other bryophyte and two lichen species all increased (Moore & Crawley, ). Clearly, much more experimental work is needed to ascertain the relationship between mosses, liverworts, and lichens in relation to the direct effects of management and the indirect effects brought about through modified vegetation structure, including both living and litter components.…”

Cryptogamic Biomass in Pannonic Acidic Sand Steppes Subject to Changing Land-Use

“…Some bryophytes also showed a rapid recovery after grazing exclusion, probably due to their ability to re-establish from fragments and to tolerate the shading caused by plant cover [ 44 ]. Generalization can be misleading due to the high variability of species-specific responses [ 116 , 117 ]. Further studies are necessary to elucidate how the effects of grazing and trampling vary by lichen growth forms and moss strategy types [ 118 ].…”

“…In the absence of grazing, successful cryptogamic competitors tend to be tall species, either bryophytes (such as Herbertus hutchinsiae Gottsche & Rabenh. in a study from Scotland) [ 117 ] or more often lichens, especially various large species of Cladonia [ 56 , 116 ]. In line with this, 50 to 60 mm tall mats of C. rangiformis , one of the tallest lichens in our study, can already effectively block smaller cryptogams and even hinder the growth of most vascular plants ( Figure 5 ).…”