교육데이터 활용•지원 서비스

This data set presents the data collected in 2014 as part of the long-term terrestrial vegetation monitoring program at Channel Islands National Park in collaboration with the Mediterranean Coast Network of the NPS Inventory and Monitoring Program. The purposes of the monitoring program are to document the long-term trends in the major vegetation communities within the park. The data collected are from 30 m point-line intercept transects. In the past, each transect was sampled annually. However, beginning in 2012 the program began adding randomly located transects to improve the representativeness of the sampling, and transitioned to a rotating panel design. Now only a core subset of the transects are now read annually. Non-core transects are assigned to one of four panels and those transects are read only once every four years. A summary analysis of the 2014 data shows that: • 98% of the transects that were to be monitored in 2014 were read (157 out of 160 transects). • The 157 transects were distributed across all five islands: Santa Rosa Island (n = 92), Santa Cruz Island (n = 24), Santa Barbara Island (n = 15), Anacapa Island (n = 13) and San Miguel Island (n = 13). • Native plant cover averaged 69% across all islands and sampled communities. The percent native cover ranged from a low of 27% in seablite scrub on Santa Barbara Island to highs of nearly 100% in coastal strand on Santa Rosa Island and caliche scrub on San Miguel Island. • In general, the number of vegetation data points recorded per transect appears to correlate with average rainfall. In other words, as rainfall increases, vegetation cover increases and this is reflected in the number of “hits” or transect points containing vegetation. When precipitation declined there was a corresponding drop in the number of hits. In 2014, as a result of 3 years of below average rainfall, the average number of hits was at an all-time low of 61. The highest average number of hits was 240 in 1993. • The number of vegetation communities varied by island. In 2014, there were 14 on Santa Rosa Island, 11 communities on Santa Cruz Island, 7 communities on San Miguel Island, 4 communities on Santa Barbara Island, and 3 communities on Anacapa Island. • Nine vegetation communities (as currently classified) occurred on more than 1 island. The most common shared community was Valley/Foothill grassland which was found in one form or another on all five islands within the park. The next most common communities were coreopsis scrub, coastal sage scrub, and island chaparral which were shared on 3 islands, although not necessarily on the same 3 islands. The other 5 shared communities – caliche scrub, coastal bluff scrub, mixed woodland, oak woodland, and riparian were shared on 2 islands each.