Forest Ecosystem Monitoring Cooperative(802) 656-0683femc@uvm.eduwww.uvm.edu/femc705 Spear StreetSouth BurlingtonVermont05403United States of AmericaUniversity of Maine Holt Research ForestpartnerHolt Research Forest Fern ObservationsLong-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.Holt Research Forest Fern ObservationsSharpeJoanneMurrayPaulinademographyherbivorylong-term monitoringdisturbancefernreproductive functionFern Observations2000-09-262024-09-13Long-term (25 years) dataset of annual observations of adult individuals of two common temperate fern species Dryopteris intermedia (Evergreen wood fern) and Dryopteris marginalis (Marginal wood fern) in the Holt Research Forest, Arrowsic Maine.To document growth and reproduction characteristics (plant sizes and mortality rates, leaf and spore production rates, leaf size) of reproductively mature plants of two common temperate fern species Dryopteris intermedia (Evergreen wood fern) and Dryopteris marginalis (Marginal wood fern). In selected years, note additional leaf and plant features (leaf breakage, insect damage, plant morphology, counts of leaflet pair, counts of leaflet pairs with sori, length of all leaves). To evaluate annual variation in fern growth and reproduction long-term (2000-2024). To assess the effects of original Holt Research Forest management protocols (2000-2019) and harvest (2020-2021) on ferns as representatives of the forest floor plant community. To compare temperate terrestrial fern demographic patterns with those of similar tropical ferns at the Luquillo Forest Long-Term Ecological Research Program (Puerto Rico) over time.Z1820_4040_OVGLLVVMC.1820.4040mySQLSharpe, Joanne M. (2024) Observations of leaves of two fern species (Dryopteris intermedia, Dryopteris marginalis) at the Holt Research Forest, Arrowsic, ME from 2020 through 2024. FEMC. Available online at: https://www.uvm.edu/femc/data/archive/project/fern-observations/dataset/fern-observationshttps://vmc.w3.uvm.edu/vmcdevel/CI4/data/archive/project/fern-observations/dataset/fern-observations-1BLOCKBLOCKBlock 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.textHRF_StudyGridBROKENLFBROKENLFLeaf breakage code, where breakage had removed upper part of leaftextD-M-YY-1Bleaf broken off in petiole or rachis (leaflet pair) section of leafBI broken due to rachis bending damage ("fem mop") attributed to the anthomyiid fly species Chirosia betuletiBSHbroken due to moth larvae shelter-building (very rare)Wleaf whole with no damage affecting leaf lengthEATENEATENHerbivory on sori on abaxial surface of fertile leaf; only recorded 2005-2011, 2019textD-M-YY-1Ydestruction of sori and smearing of spores on the underside of a fertile leafNsoral appearance normalFERTILEFERTILECount of fertile leaves (spore-bearing leaves, sporophyllis) on the monitored plantint1FIMFIMCount of fertile leaves on which sori were present but not yet mature. Only recorded for D. marginalis in years 2006-2012.int1FLAGFLAGID number associated with each study plant and written on flag (white plastic, metal wire support) with Sharpie pen (replaced as needed)intINSECT_LF_COUNTINSECT LF COUNTCount 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").int1LAMLAMLeaf lamina (blade) lengthint1LATLATLatitude of sample subquadratdecimalLONLONLongitude of sample subquadratdecimalLENGTHLENGTHLeaf length: sum of longest leaf's petiole length and lamina length measurements (PET + LAM)int1LONGESTLONGESTCategory of leaf measured (longest or not)textNall leaves on the plant except the longest; includes only leaf measurements; only measured in 2003, 2007, 2019, and 2023/24Xlongest leaf on plant, always measured when plant is monitored; includes leaf measurements as well as other descriptive leaf and plant variablesMISSCODEMISSCODECode used to indicate that plant was not found or found but not monitored a span of n number of yearstextMInwhere n = number of years missed until monitored againPCATPCATCode identifying the category of plant observationstextXfocal (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)Nadditional D. marginalis plants monitored and longest leaf measured from 2000 until death of plant or 2019 (excluding 2018)PETPETPetiole (stalk below leaflets) lengthint1PFERTPFERTCode denoting the plant reproductive status at the start of monitoring in 2000textFa spore-bearing plant (ie, sporophyllis or fertile leave present)Sno fertile leaves present, a sterile (foliage, photosynthetic) plant at the start but possibly producing sporophylls later in the studyPRSPRSCount of pairs of leaflets (pinnae) in lamina (below terminal leaflet area at the leaf tip: only recorded in 2000-2011, 2019, 2023/24int1QUADQUADQuadrat number assigned to each of four 50m x 50x areas within a blockint1Quadrat 12Quadrat 23Quadrat 34Quadrat 4SORAL_COUNTSORAL COUNTCount 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).int1SPECIESSPECIESSpecies abbreviation for the two species of fern monitored in this study.textDIDryopteris intermedia, (Evergreen wood fern)DMDryopteris marginalis, (Marginal wood fern)STATCODESTATCODECode for plant mortality statustextALplant alive and presentALMplant missing or only in 2018GYgone within past year and not seen againGgone from study before current yearSTATYEARSTATYEARFirst survey year for plant (when STATCODE = AL) or first survey year that plant is gone (when STATCODE = GY)intYYYY-1STERILESTERILECount 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)int1SUBQIDSUBQIDID code for study subquadratsint1-20sequenced ID number for the 20 sample subquadrats (BLOCK-QUAD-SUBQ combination (eg. ID: 1 = F321, 2 = 3F23...20 = 8C44)) used for fern observationTYPEPLANTTYPEPLANTCode noting the presence or absence of reproductive structures on any of the leaves during current monitoring session.textFfertile plant with fertile leaves (sporophylls) present during this monitoring periodSsterile plant with no spore-bearing fertile leaves present during this monitoring periodTYPELEAFTYPELEAFLeaf 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).textFfertile leaf with spores (sporophyll)Ssterile leaf with no reproductive structures present (vegetative, trophophyll)VCROWNVCROWNCode used to describe crown shape of plants. Only recorded in years 2008-2024.textYplant with 4 or more leaves for which the leaves form a symmetrical circle (vase-shaped crown)Nnot a vase-shaped crownWIDTHWIDTHWidth of lamina at about its midpointint1YEARYEARYear during which fall monitoring took place.dateYYYYSUBQUADSUBQUADSubquadrat number assigned to minor block subdivisions (25m x25m), four per Quadrat, used for monitoring.int1SUBQUAD 12SUBQUAD 23SUBQUAD 34SUBQUAD 4