Action: Exclude wild herbivores using physical barriers
Key messagesRead our guidance on Key messages before continuing
- One study evaluated the effects on peatland vegetation of physically excluding wild herbivores. The study was in a fen meadow.
- Vegetation cover (1 study): One replicated, paired, controlled study in a fen meadow in Poland reported that the effect of boar- and deer exclusion on vascular plant and moss cover depended on other treatments applied to plots.
- Vegetation structure (1 study): The same study reported that the effect of boar- and deer exclusion on total vegetation biomass depended on other treatments applied to plots.
- Overall plant richness/diversity (1 study): The same study reported that the effect of boar- and deer exclusion on plant species richness depended on other treatments applied to plots.
Herbivores are animals that eat plants. Wild herbivores on temperate peatlands include deer, rabbits, hares, kangaroos, feral horses, feral pigs, grouse and slugs. Insects, monkeys and other large mammals are important herbivores in tropical peat swamps. Herbivores can damage peatland vegetation directly, by eating it. Herbivores can also have indirect effects on peatland vegetation. Large animals can trample and compact peat. Beavers, introduced to Tierra del Fuego, can flood existing peatlands when they build dams or drain peatlands through channels formed when dams fail (Grootjans et al. 2014). Wild herbivores could be physically excluded from pristine peatlands to prevent damage, or from damaged peatlands to let them recover.
Key peatland types where this action may be appropriate: bogs, fens/fen meadows, tropical peat swamps.
Related actions: exclude or remove domestic livestock, which may be the dominant herbivores on peatlands; use fences or barriers specifically to protect planted/sown peatland plants.
Grootjans A., Iturraspe R., Fritz C., Moen A. & Joosten H. (2014) Mires and mire types of Peninsula Mitre, Tierra del Fuego, Argentina. Mires and Peat, 14, Article 1.
Supporting evidence from individual studies
A replicated, paired, controlled study in 2004–2007 in a degraded fen meadow in Poland (Klimkowska et al. 2010) found that the effect of fencing (to exclude wild herbivores) on vegetation depended on other treatments applied to plots: hay addition and topsoil stripping. This was true for plant species richness, vascular plant cover, moss cover and vegetation biomass (reported as statistical model results). For example, amongst areas stripped of 20 cm of topsoil, fencing increased plant species richness if hay was not added, but reduced richness if hay was added. These comparisons were not tested for statistical significance. In 2004, eight pairs of plots (8 x 16 m) were established in a drained fen meadow grazed by wild boar and deer. Eight plots (one plot/pair) were fenced to exclude these herbivores. The other plots were not fenced. Additionally, all plots were stripped of topsoil (20 or 40 cm deep), and parts of each plot were sown with hay from a nearby fen meadow (details not clear). Vegetation cover and plant species were recorded annually between 2004 (after stripping and fencing) and 2007. Total vegetation biomass was measured from clippings taken in August 2006–2007.