1. Introduction
• Abundance of invasive
species is higher > 2 km
from road.
• Abundance of native
species is higher < 3 km
from road.
• Total native plant cover is
higher far from road
• Total invasive plant cover
is higher near road.
Hypotheses
Abstract
Results
Methods
Conclusion
• Abundance of native species
with proximity to road yielded a
p-value of 0.007, and an R
squared value of 0.187 (Fig.1).
• The total amount of native
plants far away from road had
outliers, and a p-value of 0.007
(Fig. 2).
• Abundance of invasive species
was higher near road, with a p-
value of 0.002, and an R
squared value of 0.241 (Fig. 3).
• Total amount of invasive
species were only found near
road, and reported a p-value of
0.004 (Fig. 4).
• Study was conducted in
Redwood Regional Park in
Oakland.
• A total of 38 samples were
surveyed with a 1.8x1.8
quadrant.
• Quadrant had a total of 16
squares, with each square
representing six percent.
• A random number
generator was used to
generate number of
footsteps.
• Species in samples were
identified and categorized
as invasive or native.
• A regression analysis was
used to determine
abundance of plants with
proximity to road.
• Kruskal-Wallis test was
used to determine total
amount of plants found
near/far from road.
Figure 1
Figure 3
Figure 2
Figure 4
The abundance of invasive
species was much higher
near the road, therefore, the
null hypothesis was rejected.
However, the distribution of
native plants and their
proximity to roads was oddly
distributed. This result
indicates there are other
factors, besides roads,
influencing plant
distribution. Further studies
are needed to determine
these influences.
Redwood forests have been
under the influence of human
activity since California’s 1849
gold rush, when redwood logging
initiated (Save the Redwoods
League 2015). Redwood forests
tend to have high ecological
diversity with very detailed and
intricate vegetation webs, but can
be disrupted dramatically due to
human influences such as roads
(Keyes and Teraoka 2014). It is
known that effects from human
activities are prolonged in the
ecological structure of a forest,
and studies have shown that
canopy cover, basal area, and
species abundance in redwood
forests continue to be affected
even a hundred years after
harvesting has taken place
(Russell 2009).
Redwood forests are composed of intricate ecological webs, and can be easily influenced by human
activities. Abundance of invasive species was much higher near road, and abundance of native
species was higher far from road. Native plant distribution with proximity to road was oddly
distributed indicating the need for further research to determine the other influencing factors.