Butterfly Assemblages Associated with Invasive Tamarisk (Tamarix spp.) Sites: Comparisons with Tamarisk Control and Native Vegetation Reference Sites

Table 2

Environmental variables and butterfly species richness associated with landscape categories.

Landscape category	Environmental variables and species richness (mean of annual values, range in parentheses)
	Soil moisture (%)	Riparian condition	Forb and graminoid richness (number/site)	Nectar (# florets/m^2)	Butterfly species richness
NV (𝑛=7)	61^a (14–98)	6.8^a (5.6–7.4)	9^a (1–14)	43.7^a (7.5–97.6)	19^a(13–26)
MIX (𝑛=5)	49^a (16–97)	5.1^b (4.6–6.5)	10^a (7–13)	46.8^a (28.1–77.3)	18^a (14–22)
RER (𝑛=4)	49^a (15–94)	5.9^a (5.3–6.6)	7^a (3–10)	37.5^a (21.0–57.3)	15^a (10–21)
REU (𝑛=3)	37^a (1–88)	3.7^b (3.0–4.4)	2^b (0–3)	2.8^b (1.0–3.8)	13^a (4–17)
TAM (𝑛=6)	53^a (1–99)	3.8^b (2.0–5.2)	5^a (2–14)	33.4^a (1.3–69.1)	14^a (4–24)
TRT (𝑛=9)	51^a (16–97)	3.6^b (2.0–5.9)	6^a (2–10)	22.7^a (0.0–42.9)	15^a (7–23)

Column values with dissimilar letters indicate significant (𝑃<0.05) differences (Dunnett’s post hoc test) between landscape types and the reference sites NV. Variables as presented are not transformed; however, soil moisture and nectar were transformed for statistical purposes related to normality. NV: native vegetation, MIX: mixed, RER: revegetated with riparian vegetation, REU: revegetated with upland vegetation, TAM: tamarisk dominated, and TRT: treated to remove tamarisk.