(Humphrey et al., 2002). Mixed broadleaf woodlands
cover 12% of the landscape and play host to some
the most species-rich habitats in the UK (Trivedi et al.,
2017). Research into the best course of management
for optimising the adaptive resilience is high in priority
for habitat conservation, particularly in the face of
climate change (Read et al., 2009).
P. ramorum, a fungus-like tree pathogen, is one
such cause for disturbance events as it is cited as
a notifiable plant pathogen responsible for Sudden
Oak Death (Rizzo et al., 2005). P. ramorum threatens
120,000 hectares of Japanese larch in Great Britain
(Chadfield & Pautasso, 2012) with around 1,900
hectares (approximately 500,000 larch trees) having
shown symptoms of P. ramorum infection (Brasier &
Webber, 2010).
The presence of P. ramorum necessitates large-
scale forest management in the form of the removal
of its principal hosts, larch (Larix decidua and Larix
kaempferi) and rhododendron (Rhododendron
ponticum) within a 3km radius of the infection site
(Tracy, 2009). Japanese larch (L. kaempferi) and
rhododendron are both exotic species (Webber et al.,
2010, Tooley & Browning, 2018) but serve different
purposes. Rhododendron was introduced to England
in 1763 as an ornamental plant (Barron & Little,
2009), while Japanese larch was imported to Britain
in the 17th Century for use as a nurse tree (Smith,
2017, Nord-Larsen & Meilby, 2016). P. ramorum
biosanitation removes these organisms to decrease
the risk of spreading pathogens within afflicted
woodland (Rizzo et al., 2005). All biomass (inoculum)
that may harbour the offending pathogen is removed
from the infected site, ensuring the destruction of the
offending organism through burning (Kliejunas, 2010).
The most prominent form of P. ramorum biosanitation
is the clear felling of all Japanese larch, within the
affected region (Patausso et al., 2010), although this
method has its drawbacks. The opening of woodland
canopies has been shown to increase understory
flora biodiversity (Kirby et al., 2017), the removal of
an entire species from an ecosystem diminishes niche
variation: the different types of habitats offered by
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an ecosystem. This affects the species richness of
reliant organisms, which has adverse effects on an
ecosystem’s health. These effects are able to persist
for hundreds of years (Boyd et al., 2013), leading to
irreversible landscape homogenisation (Staley et al.,
203). Additionally, acute and abrupt conifer clearing
(e.g. larch felling) increases light exposure to harmful
levels, decreasing soil fertility (Jianwei & Chengqiu,
1999). This significantly reduces species richness
of sensitive specialised flora (Brown et al., 2015),
contributing to the decline of species diversity in
woodland plant communities for several decades
(Keith et al., 2009).
In Keele Springpool Wood
In response to an outbreak of the notifiable and
deadly plant pathogen P. ramorum, Springpool
Wood at Keele was placed under a cordon sanitaire
in accordance with the Forestry Commission’s
(FC) Statutory Plant Health Notice on 7 August
2013. Between July 2014 and April 2015, 1600
L. kaempferi and all R. ponticum were cut down in
Springpool Wood to eliminate P. ramorum and its
key sporulating hosts, with further removal of R.
ponticum taking place across Keele University campus
until October 2015. The cut stumps were treated
with herbicide to prevent regrowth and potentially
P. ramorum-infected plant material was reportedly
burned onsite. Complete root removal of infected
rhododendron was carried out in Bluebell Wood, but
this was not possible in lower Springpool Wood.
These environmental disturbances severely cut away
at the woodland ecosystem, with the combined action
of increased light levels and soil disturbance providing
optimal conditions for the invasion of opportunistic
plants. The presence of non-native invasive Japanese
knotweed (Fallopia japonica) and Himalayan balsam
(Impatiens glandulifera) have both been documented
in the woodlands and can readily spread into the
disturbed regions, with detrimental impacts on ground
flora biodiversity (Vilà et al., 2011). A full inventory
of rhododendron had not been carried out since
student surveys in 2011, but further surveys from
2018 indicated extensive regrowth of cut stumps and