given a hand lens, tally counter, data sheets, and a clipboard. Each
group was paired with a USDA-ARS scientist or technician and asked
to visit the four native habitats plus the invaded habitat in the KIND
Garden. Native habitats are all of similar size and are maintained to
prohibit invasion by non-native species. Within each habitat students
collected data on the number of tree, shrub, and herbaceous plant
species they encountered, as well as the number of invertebrate
and vertebrate animal species present, taking care to not disturb species that could be dangerous to handle ( i.e., bees, wasps, ants, etc.).
Field guides were provided in case a student wanted to learn more
about a particular insect or plant species. However, due to time constraints, varying expertise of the facilitators, and the overall goal to
identify differences among habitat types, not to identify organisms
to species, plants and animals were classified as “morphospecies.”
In this case, if two individuals looked alike, they were classified as
the same species. After recording data in the five different habitats,
the students gathered in a classroom to examine the data.
Each group totaled the number of species recorded in each
habitat they surveyed. Species in each trophic level were lumped
together into one group (total species) to save time. They then
reported the number of species they encountered in each habitat
to an instructor, who created a table on a dry-erase board. Each
group’s report was treated as a separate “replicate.” The mean number of species found in each habitat was calculated and graphed on
the dry-erase board in front of the students (Figure 2). The students
were then asked a series of questions to facilitate a discussion to
interpret the graph and synthesize their observations:
1. Which habitat type had the highest diversity? Why?
2. Which habitat type had the lowest diversity? Why?
3. How does the number of plant species present in a habitat
influence animal diversity?
From the graph of their data, the group immediately recog-
nized that species diversity was much higher in the native habitats
than in invaded areas. The invaded habitat is physically the largest
region of the KIND Garden, but the students observed the lowest
number of species in this habitat. We discussed the ability of inva-
sive plants to outcompete natives, and how invasive weeds often
form monocultures, decreasing biodiversity. We also discussed
the differences in student opinion between the “before” show-of-
hands survey and after visiting the KIND Gardem on how impres-
sions regarding biodiversity and invasive species may have
changed. After the exercise, the students had a much better under-
standing of how invasive plants affected biodiversity and how a
decline in the number of plant species in an area could lead to a
decrease in species in other trophic levels.
The invaded habitat of the KIND Garden features weeds that have
been the targets of USDA-ARS Invasive Plant Research Laboratory
biological control programs. The majority of arthropods observed
in this habitat were biological control agents. This reduction in
arthropod (and other animal) diversity in areas invaded by exotic
plants is common, as illustrated in a meta-analysis on the impacts
of invasive exotic plants (Vilá et al., 2011).
Several recent studies have sought to quantify the impact of non-native plants by evaluating community composition in habitats
dominated by native versus non-native plants. Although the current
student exercise used a very coarse estimate of biodiversity, with
species from all trophic levels lumped together, our results are consistent with these studies. Insect communities are more diverse on
native plants compared to non-native plants in early successional
communities (Ballard et al., 2013), forest thickets (Fickenscher
et al., 2014), and experimental landscapes consisting of native
and non-native woody congeners (Burghardt & Tallamy, 2013).
Furthermore, landscapes dominated by native plants support
increased diversity at higher trophic levels, including avian diversity
(Burghardt et al., 2009). More detailed comparisons for this exercise
are possible by calculating the number of species in each trophic
level for each habitat and comparing among habitats.
Lessons and activities that teach about biological invasions and
their impacts on biodiversity are directly applicable to several of
the Next Generation Science Standards. The KIND Garden biodiversity activity, although designed for grades 5–7, can be modified to
fulfill the standards for other grade levels (Table 1). Modifications
for middle school students include comparing diversity at different
trophic levels or feeding guilds and creating food webs. Students
could then be challenged to predict the results of perturbations to
these food webs. For high school students, modifications focus on
more sophisticated data collection and analysis, such as calculating
diversity indices and synthesizing what they have learned to create
a restoration plan for a site. There are also opportunities to integrate
this activity with other disciplines such as math, health, economics,
and history. For example, students could research the role of acclimatization societies in moving organisms around the world and
the consequences of this global movement. Students could also
research the effects of moving non-native species through global
trade ( i.e., horticulture, pet trade, shipping contaminants). Students
could discuss both the benefits (increased commerce through
exchange of these goods) and the costs (controlling invasive organisms and potential loss of beneficial natives), and determine if the
benefits outweigh the costs.
Many schools may already have contrasting communities in place
if landscaping that consists primarily of non-native plants and non-
Figure 2. Species richness (average number of species ± SE)
in each habitat type. Overall, students observed fewer species
in the invaded habitat than in the native habitats.