3.3 Directional eco-effect
The exploitation of the directional eco-effect existing in the EP responses of the LEP, AEP, and HEP ecosystems to the snow-onset, -end, and both -onset&-end SP over the NH area was operated (Supplementary Fig. 8), and so did for the NA (Supplementary Fig. 9) and NE (Supplementary Fig. 10), with their directional eco-effects of the snow-onset&-end SP-related case displayed in Fig. 7. The specific leading directions along with latitudes in each of the cases were also displayed (the inserted boxes in Fig. 7). The statistics of all of these results are shown in Fig. 8, with the leading geo-grid ratios listed in each case of combining the three traits – LEP, AEP, and HEP, the eight directions in the correlation window, and the three regions of NH, NA, and NE. Globally, the leading directions are distinctive between these cases when regarding the directional eco-effect, especially for the whole NH. Nevertheless, it still could be distinguished that in terms of directional eco-effect, the EP-SP responses over the NA were more to north while the NE more to south.
-Insert Fig. 7 here-
-Insert Fig. 8 here-
Overall, the derived neighborhood eco-effect and directional eco-effect together can verify the applicability of the newly proposed “periconnection” conceptual framework. After all, before its proposal, it is quite difficult to get the inferences as did in this study. The resulting 3.14%, 3.38%, and 3.46% (listed in Fig. 2d–f, respectively), equivalently, relate to the potential derivations based on the traditional attribution analysis methods (Winkler et al.,2018), and such low ratios cannot reflect the EP situations of the whole continents in a statistical sense. Now, the creatively revealed periconnection-related eco-effects can expose more reliable information about the underlying rules of snow cover phenological variations affecting ecosystem activities. Overall, the contributions of this study are equal to opening a new way for investigating from ecology to Earth interactions, and hence, we encouraged more uses of periconnection to vigorously discover more about the causes, processes, evolutions, and patterns of various natural phenomena in ecology, global change, and Earth interaction in the future.