Species abundance along the railway of Kashmir Himalaya

1. The significant portion of global terrestrial biodiversity
harbored in mountains is under increasing threat from a variety of
anthropogenic impacts. Protecting fragile mountain ecosystems requires
understanding how these human disturbances affect biodiversity. As roads
and railways are extended further into mountain ecosystems, understanding
the long-term impacts of this infrastructure on community composition and
diversity gains urgency. 2. We used railway corridors constructed across
the mountainous landscapes of the Kashmir Himalaya from 1994-2013 to study
the effects of anthropogenic disturbance on species’ distributions and
community dynamics. In 2014 and 2017, we collected vegetation data along
31 T-shaped transects laid perpendicular to the railway line, adopting the
MIREN (Mountain Invasion Research Network) road survey
methodology.  3. Plant communities shifted significantly
from 2014 to 2017, potentially as a result of ongoing species’
redistribution after railway construction, mostly driven by declines in
both native and non-native species richness, and increasing abundance of a
few non-native species, especially in areas away from the railway
track.  4. These patterns indicate an advancing succession, where
initial – rare – pioneering species are replaced by increasingly dominant
and often non-native competitors, and potentially suggest a trend towards
delayed local extinctions after the disturbance event. Native and
non-native species richness were negatively correlated with elevation, but
that relationship diminished over time, with the abundance of non-natives
significantly increasing at high elevations.  5. Synthesis and
applications: Transport corridors seem to facilitate the spread of
non-native species to higher elevations, which has serious implications in
light of the warming mountain tops. Our results indicate that plant
communities next to railways do not reach equilibrium quickly after
disturbance. More than 10 years after railway establishment succession
continued, and signs pointed in the direction of a landscape increasingly
dominated by non-native species. Our study indicates that the single
disturbance event associated with construction of a railway in the
Himalayas had large and long-lasting effects on plant communities at and
around this transport corridor, and suggests the need for a long-term
region-wide coordinated monitoring and management program.