Dataset: Fern Observations

Holt Forest research area major subdivisions (100m x 100m): number (south-north coordinate) + letter (north-south coordinate)

Code for no leaf on plant being full length, but shortened because of breakage or insect damage below the tip of the leaf.F11. B = broken leaf.

Sori (with spores inside) are attacked at some point during the year, probably by insect larvae, creating a "smeared" effect on the back of leaves and occasional brown spots on the top of the leaves. Y = sori destroyed

Count of the leaves on the monitored plant that had spore bearing stuctures (sorus, pl sori) on the bottom surface of the leaf

Number of leaves on monitored plant that were fertile, but by the monitoring date (Sept/Oct) the sori were not yet mature (leaf assumed to have emerged mid-summer)

Plants were assigned an ID number when first monitored 1; a white flag marked with the number (Sharpie) was put in the ground near the plant and re-marked or replaced as needed throughout the study. Not all numbers between 1 and 849 were used to identify the 719 plants in the study.

Number of leaves on monitored plant with development that had been stopped by an insect (type unknown) that at some point along the rachis "rolled" the remaining developing pairs of leaflets into a "ball"; usually occurred at about leaflet pair 3 or 4 counting from the bottom, and leaflet pairs belo

Sum of long petiole length and lamina length measurements

Length of the lamina of the longest leaf on plant

Notes about plant locations printed on data sheets used for each year's monitoring: usually in relation to other flagged plants and may have changed from year to year to improve the plant location process

Length of the petiole of the longest leaf on plant

Code indicating plants in each study subquadrat that were randomly selected during the first year of the survey for extra measurements. These plants had ALL leaves measured to obtain info on the relationship between longest leaf length and mean leaf length for plants with that longest measured leaf.

Count of pairs of leaflets (toward tip until merged into a terminal leaflet) in the lamina on longest leaf of plant; noted from the beginning of study (2000) through 2011 and again in 2019 only

Holt forest major block divisions (50m x 50m), four per block

Count of the number of pairs of leaflets with sori on the longest fertile leaf measured (0 = terminal only, blank = sterile leaf or data for this variable not collected)

Abbreviation for the two species of fern monitored in this study. DI = Dryopteris intermedia and DM = Dryopteris marginalis

Code indicating that the plant has died, was missing or not surveyed.

First survey year for plant (STATCODE = AL) or first survey year that plant is gone (STATCODE = G) or year that plant was missing (STCODE = MIn) though found alive in subsequent surveys

Count of the leaves on the monitored plant that did NOT have spore bearing stuctures (sorus, pl sori) on the bottom surface of the leaf (includes observations of leaflets on broken leaves as well where the tip of the leaf may have been fertile)

Assigned sequence number (1-20) for sample units (subquadrats) used in THIS study (BLOCK-QUAD-SUBQ combination (eg 1 = F321, 2 = 3F23…20 = 8C44))

Holt forest minor block subdivisions (25m x 25m), four per block; basic "study plot" sampling area in THIS study

On fertile plants where the longest leaf was not fertile, this code indicates that a sterile leaf was measured. Happens occasionally (3.6% of all lvs in study)when the sterile leaf happens to be longer, or all fertile leaves were broken. In early years (prior to 2007) the leaf type was not noted.

In the monitoring year, the plant has produced one or more fertile (spore-bearing) leaves or is sterile, having produced only photosynthetic leaves

Code used in later years to describe plants with 4 or more leaves for which the leaves formed a complete circle, suggesting that all croziers had successfully emerged and matured; these plants were therefore capable of maximum leaf litter accumulation

Width of lamina at about midpoint for the longest leaf on plant

Year during which fall monitoring took place