saunders {untb} | R Documentation |
A dataframe with each row representing species inventories for a kelp
holdfast (saunders
) together with a Boolean flag indicating
whether the holdfast was in a sheltered or exposed location. Also two
data frames, one for the 20 exposed holdfasts (saunders.exposed
)
and one for the 20 sheltered holdfasts (saunders.sheltered
).
Also three count
objects, giving counts for all organisms
(saunders.tot
), all those from exposed locations
(saunders.exposed.tot
), and all those from sheltered locations
only (saunders.sheltered.tot
).
data(saunders)
Dataset saunders
is a data frame with 40 observations on 177
variables. The observations (rows) are 40 holdfasts and the variables
are, with the exception of the first one, the numbers of each of 176
species living there. The first variable is a Boolean, indicating
whether or not that holdfast was exposed (TRUE
) or sheltered
(FALSE
).
Summary datasets saunders
, saunders.exposed
, and
saunders.sheltered
are objects of class count
that
are the species abundance for sheltered holdfasts, exposed
holdfasts, and the entire dataset.
Kelp are large seaweeds classified in kingdom Chromista. Kelp grows in shallow oceans in kelp forests.
The holdfast is a root-like structure that anchors the kelp to the ocean floor. Fauna inhabiting kelp holdfasts, being “incredibly diverse” (Anderson et al 2005), are often used as indicators of environmental change.
The data was collected in New Zealand, from eight sites along the Leigh coastline from north of Leigh Harbour down to the southern end of Kawau Island (a stretch of roughly 20 km). Four sites were wave-exposed, four were sheltered (although two of the latter were arguably quite tidally-dominated). Each site had a spatial extent of roughly one hectare. They were collected from 5 - 10 November, 2003
It is not entirely obvious how to derive the summary datasets from the
saunders
dataframe. Use function extractor()
for this.
Data supplied by Justine Saunders
data(saunders) plot(saunders.sheltered.tot, uncertainty=TRUE, n=1) preston(saunders.tot) plot(extant(extractor(saunders,1)))