Figure 1.
Organization of the NEXCADE analysis pipeline.
Figure 2.
Query submission protocol in the NEXCADE web server.
(A) Selection of network type, (B) Data entry form.
Figure 3.
NEXCADE Result & Analyses for a given network.
Panel A shows four distinct sections, for input data visualization (Section I) and perturbation analyses (Section II - IV). The lower panel B depicts labeled node visualization for an example dataset with nine disconnected clusters (left) along with topological statistics of the generated network (right).
Figure 4.
A typical use of NEXCADE for Single Node Perturbation.
The network (A) before and (B) after extinction of the species Prunus spinosa, are shown. As can be seen, a single perturbation can result in a large number of associated co-extinctions of other affiliate species (Panel C). Users can compare change in network attributes (A with B), and view list of affected nodes, secondary extinctions and remaining interactions in the sub-network. High resolution graphics of networks can be drawn with and without labels.
Figure 5.
Results of clustered perturbation simulated on the example network shown in Figure 3.
Clicking section III in Figure 3A enables users to: (A) select a group of target nodes based on degree and (B) analyze the affect of perturbation. Clicking the first option on this page returns Panel (C) - the selection form for simulating clustered edge perturbation on the edges of pre-selected nodes and the resulting sub-network can be analyzed comparatively as shown in (D). As can be seen in panel (E), the reduced sub-network upon clustered node perturbation is much fragmented and smaller, in contrast with the unperturbed network shown in Figure 3B.
Figure 6.
Outcome of random and ordered sequential perturbation on GNIC.
Clicking section IV in Figure 3A enables users to simulate three distinct co-extinction curves, namely (A) specialist-first, (B) generalists first, and random cascades. Panels (C) and (D) depict the contrasting network responses between two opposing extinction sequences, resulting in complete collapse at 52 and 195 extinctions respectively. Plots in panels (E) and (F) show this contrasting response in terms of network size and secondary extinctions. When node removals are simulated from the most-linked to least-linked species (red curves), the network collapses much faster, and secondary extinctions begin at a very early stage, as compared to the opposing node loss sequence (green curves). Random co-extinction curves are depicted in Black. Panels (G) and (H) show the status of the network at equivalent number of node removals in the two opposing extinction series.