Long-Term Deer Exclusion Releases Dwarf Bamboo, Reducing Vascular Plant Diversity

Sammanfattning

AimsOvergrazing by excessive deer populations harms native plant communities across most north temperate and boreal regions. In regions where deer impact is particularly severe, fencing is sometimes employed as a conservation measure to safeguard rare and threatened species and ecosystems. Here we examine how forest vascular plant communities have been affected by 21 years of sika deer exclusion by fencing of a 900 ha area.LocationNikko National Park, Tochigi prefecture, Japan.MethodsWe surveyed vascular plant cover in 240 plots and measured forest density on both sides of the fence in stands dominated by larch (Larix kaempferi) and oak (Quercus crispula).ResultsVascular plant species richness was found to be lower in forest areas protected by the fence. At the same time, dwarf bamboo, often the most abundant understory component in Japanese open forests, was taller and denser inside the fence where deer had been excluded. In addition, the lack of natural tree regeneration inside the fence, likely due to strong dwarf bamboo competition, was also notable. This suggests that deer exclusion has benefitted dwarf bamboo while inhibiting the competition of other species, thereby lowering vascular plant richness. Vascular plant communities outside the fence instead seem to be strongly shaped by abundant sika deer; several species found there are known to be unpalatable or grazing tolerant, and there were few tree seedlings.ConclusionThese results show that fencing to protect forest flora against overgrazing may have unintended consequences where there is a risk that competitive species can dominate understory plant communities. Instead of fencing, improved game management to maintain moderate deer populations may be a better strategy for large-scale conservation of forest flora and for promoting natural tree regeneration.

Nyckelord

biodiversity; deer fence; forest flora; Japan; Larix kaempferi; Nikko; Quercus crispula; Quercus mongolica var. crispula; temperate forest; ungulate grazing

Publicerad i

Applied Vegetation Science
2025, volym: 28, nummer: 1, artikelnummer: e70018
Utgivare: WILEY

SLU författare

• Petersson, Lisa

  • Institutionen för sydsvensk skogsvetenskap, Sveriges lantbruksuniversitet
    
  • Utsunomiya University

• Salk, Carl

  • Institutionen för sydsvensk skogsvetenskap, Sveriges lantbruksuniversitet
    
  • Institute for Globally Distributed Open Research and Education (IGDORE)

• Thor, Göran

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Ekologi
Skogsvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.1111/avsc.70018

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/141288