Skip to main content
Fig. 6 | Fire Ecology

Fig. 6

From: Understory community shifts in response to repeated fire and fire surrogate treatments in the southern Appalachian Mountains, USA

Fig. 6

A dendrogram of clustered plots (n = 117) derived from the agglomerative hierarchical cluster analysis (AHCA) for herbaceous vegetation shows five distinct clusters (labeled 1 through 5) in response to treatments (control = C, burned four times = B, mechanical removal two times of stems <10 cm dbh = M, and combination of M and B = MB). Data from 2016 were used in this study (2001 to 2016) of plant community change in response to fuel treatments in Green River Game Land, North Carolina, USA. A Bray-Curtis approach was used as the distance metric and a flexible beta linkage was used as the fusion strategy to determine the appropriate number of clusters. The cluster number was determined from fusion height, a visualization method that shows natural breaks in the data, indicating the highest number of plot similarities. Each line on the dendrogram is denoted by orange (burned four times; B), black (control; C), purple (mechanical treatment two times; M), and blue (mechanical treatment two times plus burned four times; MB) dots that indicate which treatment was applied to that plot. Cluster 1 had nine plots in B, 14 in C, 12 in M, and zero in MB, categorizing it as having a different response from C (category 2; Cat. 2). Cluster 2 had eight plots in B, zero in C, zero in M, and 20 in MB, falling under category 2. Cluster 3 had one plot in B, six in C, four in M, and one in MB, falling under category 2. Cluster 4 had five plots in B, five in C, five in M, and two in MB, categorizing it as having a similar response to C (category 1; Cat. 1). Cluster 5 had seven plots in B, three in C, eight in M, and seven in MB, falling under category 1. The horizontal axis at the bottom of the dendrogram represents the distance or dissimilarity between clusters

Back to article page