• Address:
  705 Spear Street
  South Burlington, Vermont 05403
  United States of America
  
  Phone: (802) 391-4135
  Email: femc@uvm.edu
  Website: www.uvm.edu/femc

Long-term observations of two fern species (Dryopteris intermedia and Dryopteris marginalis ) at the Holt Research Forest. Annual variation in fern leaf production, leaf size, spore production, and other observed characteristics. Plant observations from an annual fall monitoring visit began in 2000 and were completed in 2024.

• Label: BLOCK

• Description: Block number-letter combination identifying Holt Research Forest major research area subdivisions (100m x 100m): number (west-east coordinate) + letter (north-south coordinate) used in Fern Observation Study.

• Storage Type: text

• Measurment Type: nominal

• Location List: BLOCK
• • Code: HRF_StudyGrid
  • • Definition:

Attribute Name: BROKENLF
• Label: BROKENLF
• Description: Leaf breakage code, where breakage had removed upper part of leaf
• Storage Type: text
• Measurment Type: nominal
• String Format: D-M-YY
• Number Type: -1
• Custom List: BROKENLF Codes
• Code: B
• Definition: leaf broken off in petiole or rachis (leaflet pair) section of leaf
• Code: BI
• Definition: broken due to rachis bending damage ("fem mop") attributed to the anthomyiid fly species Chirosia betuleti
• Code: BSH
• Definition: broken due to moth larvae shelter-building (very rare)
• Code: W
• Definition: leaf whole with no damage affecting leaf length

• Label: EATEN

• Description: Herbivory on sori on abaxial surface of fertile leaf; only recorded 2005-2011, 2019

• Storage Type: text

• Measurment Type: nominal
• String Format: D-M-YY
• Number Type: -1

• Custom List: EATEN Codes
• Code: Y
• Definition: destruction of sori and smearing of spores on the underside of a fertile leaf
• Code: N
• Definition: soral appearance normal

• Label: FERTILE

• Description: Count of fertile leaves (spore-bearing leaves, sporophyllis) on the monitored plant

• Storage Type: int

• Measurment Type: interval
• Precision: 1

• Label: FIM

• Description: Count of fertile leaves on which sori were present but not yet mature. Only recorded for D. marginalis in years 2006-2012.

• Storage Type: int

• Measurment Type: interval
• Precision: 1

• Label: FLAG

• Description: ID number associated with each study plant and written on flag (white plastic, metal wire support) with Sharpie pen (replaced as needed)

• Storage Type: int

• Measurment Type: interval

• Label: INSECT LF COUNT

• Description: Count of leaves with herbivory in the form of a gall attributed to the larvae of an amthomyiid fly (Chirosia betuleti) where leaf development had been arrested by the formation of a rolled rachis forming a cluster of developing pairs of leaflets (a structure sometimes referred to a "mop-head").

• Storage Type: int

• Measurment Type: interval
• Precision: 1

• Label: LAM

• Description: Leaf lamina (blade) length

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit: cm

• Label: LAT

• Description: Latitude of sample subquadrat

• Storage Type: decimal

• Measurment Type: interval
• Unit: cm

• Label: LON

• Description: Longitude of sample subquadrat

• Storage Type: decimal

• Measurment Type: interval
• Unit: cm

• Label: LENGTH

• Description: Leaf length: sum of longest leaf's petiole length and lamina length measurements (PET + LAM)

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit: cm

• Label: LONGEST

• Description: Category of leaf measured (longest or not)

• Storage Type: text

• Measurment Type: nominal
• Unit:

• Custom List: LONGEST Codes
• Code: N
• Definition: all leaves on the plant except the longest; includes only leaf measurements; only measured in 2003, 2007, 2019, and 2023/24
• Code: X
• Definition: longest leaf on plant, always measured when plant is monitored; includes leaf measurements as well as other descriptive leaf and plant variables

• Label: MISSCODE

• Description: Code used to indicate that plant was not found or found but not monitored a span of n number of years

• Storage Type: text

• Measurment Type: nominal
• Unit:

• Custom List: MISSCODE Codes
• Code: MIn
• Definition: where n = number of years missed until monitored again

• Label: PCAT

• Description: Code identifying the category of plant observations

• Storage Type: text

• Measurment Type: nominal
• Unit:

• Custom List: PCAT Codes
• Code: X
• Definition: focal (or profile) plants (7 per species per block) longest leaf monitored from 2000 until death of plant or end of study (2023(Blocks 3F, 5E) or 2024 (Blocks 7C, 8C)) with all leaves on the plants measured in selected years (2003, 2007, 2019, 2023/2024)
• Code: N
• Definition: additional D. marginalis plants monitored and longest leaf measured from 2000 until death of plant or 2019 (excluding 2018)

• Label: PET

• Description: Petiole (stalk below leaflets) length

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit: cm

• Label: PFERT

• Description: Code denoting the plant reproductive status at the start of monitoring in 2000

• Storage Type: text

• Measurment Type: nominal
• Unit:

• Custom List: PFERT Codes
• Code: F
• Definition: a spore-bearing plant (ie, sporophyllis or fertile leave present)
• Code: S
• Definition: no fertile leaves present, a sterile (foliage, photosynthetic) plant at the start but possibly producing sporophylls later in the study

• Label: PRS

• Description: Count of pairs of leaflets (pinnae) in lamina (below terminal leaflet area at the leaf tip: only recorded in 2000-2011, 2019, 2023/24

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit:

• Label: QUAD

• Description: Quadrat number assigned to each of four 50m x 50x areas within a block

• Storage Type: int

• Measurment Type: interval
• Unit:

• Custom List: QUAD Codes
• Code: 1
• Definition: Quadrat 1
• Code: 2
• Definition: Quadrat 2
• Code: 3
• Definition: Quadrat 3
• Code: 4
• Definition: Quadrat 4

• Label: SORAL COUNT

• Description: Count of the number of pairs of leaflets on the longest fertile leaf with sori present (0 = terminal only). Only recorded in 2005, 2006, 2008-2011 for all longest fertile leaves and in 2019 for longest fertile leaves on focal plants (pcat = X).

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit:

• Label: SPECIES

• Description: Species abbreviation for the two species of fern monitored in this study.

• Storage Type: text

• Measurment Type: nominal
• Unit:

• Custom List: SPECIES Codes
• Code: DI
• Definition: Dryopteris intermedia, (Evergreen wood fern)
• Code: DM
• Definition: Dryopteris marginalis, (Marginal wood fern)

• Label: STATCODE

• Description: Code for plant mortality status

• Storage Type: text

• Measurment Type: nominal

• Custom List: STATCODE Codes
• Code: AL
• Definition: plant alive and present
• Code: ALM
• Definition: plant missing or only in 2018
• Code: GY
• Definition: gone within past year and not seen again
• Code: G
• Definition: gone from study before current year

• Label: STATYEAR

• Description: First survey year for plant (when STATCODE = AL) or first survey year that plant is gone (when STATCODE = GY)

• Storage Type: int

• Measurment Type: datetime
• String Format: YYYY
• Number Type: -1

• Label: STERILE

• Description: Count of sterile leaves (photosynthetic only, vegetative, trophophyllis) on the monitored plant and lacking spore bearing structures (sorus, pl sori) on the lower surface of the leaf (includes observations of broken leaves even though it is not known if the upper part of the leaf had spores)

• Storage Type: int

• Measurment Type: interval
• Precision: 1

• Label: SUBQID

• Description: ID code for study subquadrats

• Storage Type: int

• Measurment Type: nominal

• Custom List: SUBQID Codes
• Code: 1-20
• Definition: sequenced ID number for the 20 sample subquadrats (BLOCK-QUAD-SUBQ combination (eg. ID: 1 = F321, 2 = 3F23...20 = 8C44)) used for fern observation

• Label: TYPEPLANT

• Description: Code noting the presence or absence of reproductive structures on any of the leaves during current monitoring session.

• Storage Type: text

• Measurment Type: nominal

• Custom List: TYPEPLANT Codes
• Code: F
• Definition: fertile plant with fertile leaves (sporophylls) present during this monitoring period
• Code: S
• Definition: sterile plant with no spore-bearing fertile leaves present during this monitoring period

• Label: TYPELEAF

• Description: Leaf type code indicating sterile (vegetative) or fertile (reproductive) functional status of the leaf measured; if not recorded assumed as TYPEPLANT (2000-2002 and 2004-2006).

• Storage Type: text

• Measurment Type: nominal

• Custom List: TYPELEAF Codes
• Code: F
• Definition: fertile leaf with spores (sporophyll)
• Code: S
• Definition: sterile leaf with no reproductive structures present (vegetative, trophophyll)

• Label: VCROWN

• Description: Code used to describe crown shape of plants. Only recorded in years 2008-2024.

• Storage Type: text

• Measurment Type: nominal

• Custom List: VCROWN Codes
• Code: Y
• Definition: plant with 4 or more leaves for which the leaves form a symmetrical circle (vase-shaped crown)
• Code: N
• Definition: not a vase-shaped crown

• Label: WIDTH

• Description: Width of lamina at about its midpoint

• Storage Type: int

• Measurment Type: interval
• Precision: 1
• Unit: cm

• Label: YEAR

• Description: Year during which fall monitoring took place.

• Storage Type: date

• Measurment Type: datetime
• String Format: YYYY
• Unit:

• Label: SUBQUAD

• Description: Subquadrat number assigned to minor block subdivisions (25m x25m), four per Quadrat, used for monitoring.

• Storage Type: int

• Measurment Type: nominal

• Custom List: SUBQUAD Codes
• Code: 1
• Definition: SUBQUAD 1
• Code: 2
• Definition: SUBQUAD 2
• Code: 3
• Definition: SUBQUAD 3
• Code: 4
• Definition: SUBQUAD 4

• Fern Observations
  • Method Description: Four 100m x 100m blocks of the gridded Holt Research Forest maps were chosen in 2000 for study: two from the “managed or to be managed” western section and two from the “control” eastern section of the Holt Forest based on 1980’s releve maps showing where highest densities of ferns were found. Only Dryopteris marginalis (Marginal wood fern) and Dryopteris spinulosa (later split into three species including Evergreen wood fern (Dryopteris intermedia) monitored in this study) had high densities in more than a few small areas of the forest. Both species retain a live canopy until after emergence of the following year’s leaves. Within these four plots, five subquadrats that had high densities of the selected fern species were randomly chosen for long- term observation. Seven reproductively mature (spore-bearing leaves present) individuals of D. intermedia and up to fifty of the more common D. marginalis (with seven randomly assigned as “focus plants” to be compared with D. intermedia) were chosen for observation and identified by white flags marked with an ID number. During annual monitoring sessions after the end of the growing season (September-November) a study plant (if it was still alive) was located and various characteristics of the leaf and plant were recorded. The longest leaf of the 14 focus plants was measured every year from 2000 through 2025 as well as all leaves in the crown in 2003, 2007, 2019 and 2023/24. Various other fern traits (count of reproductive (fertile leaves (spore- bearing; sporophylls) and photosynthesis-only (sterile leaves; trophophylls) structures; leaflet pair counts, evidence of insect damage, crown morphology) were recorded in all or some years of the study.

• Sampling Equipment
• Sampling Description: Plants were identified using a white plastic flag on a wire support put in the ground near the plant. ID numbers were written on the flag with Sharpie. Leaves were measured using a 30- cm ruler and observations were written in a waterproof field book or on waterproof checklists.