statisticalModeling (version 0.3.0)

Alder: Nitrogen fixing by alder plants

Description

These data were collected by biologist Mike Anderson in a study of nitrogen fixation by bacteria growing on the root nodules of alder bushes.

Usage

data(Alder)

Format

A data frame Alder with 196 rows and 24 variables:

• LAND. landscape, floodplain vs. upland.
• SAMPPER. sampling period: early, mid, late
• SPECIES. host species, Alnus tenuifolia (AT) vs. A. crispa (AC)
• STAGE. successional stage, early vs. late in floodplain and upland landscapes. This is not equivalent across landscapes.
• JULDAY. Julian day
• PERNODN. nodule percent nitrogen by mass
• RF. bacterial genotype
• SNF. nitrogen fixation rate of nodule tissue, umol N2/gram of nodule dry weight/hr
• SLA. specific leaf weight, grams of leaf weight/square-meter, dry
• ONECM. soil temperature at 1 cm depth
• FIVECM. soil temperature at 5 cm depth
• PERH2O. soil moisture, percent H2O by mass
• DEL. del15N of leaf tissue
• DELNOD. del15N of nodule tissue
• NPERAREA. leaf nitrogen content per unit leaf area
• NDiff. nitrogen content difference between leaf and nodule of the same plant
• delDiff. del15N difference between leaf and nodule of the same plant
• SITE. Site designations: 1A,B,C for replicate early succession floodplain sites, 4A,B,C for late succession floodplain, UP1A,B,C for early succession upland and UP3A,B,C for late succession upland
• HABSPEC. habitat+species, concatenated LAND, STAGE, SPECIES
• SITESPEC. concatenated SITE, SPECIES
• REP. replicate site within a given level of HABSPEC
• PLNO. plant number, unique for individuals of each species (AT1-180, AC1-270)

Source

Michael Anderson

Details

Two questions that Anderson wanted to answer are: (1) Can any variation in nitrogen fixation (variable SNF) be attributed to genotype (variable RF)? (2) What are the major sources of variation in SNF and PERLEAFN? Variables of biological interest are seasonality (SAMPPER or JULDAY), soil temperature and moisture, and habitat differences (STAGE for host species AT andSTAGE and LAND for host species AC).

Three replicate sites were sampled for each landscape/stage combination in three sampling periods across the growing season. Site sampling was arranged in a Latin Square design in order to systematize any effects of seasonality on N2-fixation rates.

References

Anderson MD, Ruess RW, Myrold DD, Taylor DL. ``Host species and habitat affect modulation by specific Frankia genotypes in interior Alaska'' Oecologia (2009) 160:619-630.

Examples

mod <- lm(logSNF ~ RF + SITESPEC, data = Alder)