Gregory S. Gilbert ggilbert@ucsc.edu University of California, Santa Cruz

Alexander S. Jones asjones@ucsc.edu University of California, Santa Cruz

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Abstract: Here we present stem-based data from the first three censuses of the 16-ha UC Santa Cruz Forest Ecology Research Plot, located in the Mediterranean climate forest of coastal central California, USA. The forest includes both mixed evergreen forest and redwood-dominated forest, and is recovering from significant logging disturbance in the early 20th century. Each woody stem with diameter larger than 1 cm has been mapped, tagged, identified, and measured, with censuses on a ~5-year interval. The first census (FERP1) began in 2007, and included just 6 ha. During FERP2, begun in 2011, the plot was expanded to 16 ha. The FERP3 census was begun in 2017. The community includes 34 woody species, including 4 gymnosperm and 9 angiosperm tree species, 18 species of shrubs, and 3 species of lianas. Across the three censuses we report identity, size, location, and mortality data from 48,556 stems of 31,206 mapped individuals.

The authors appreciate prior consultation over potential co-authorship for significant analysis and publication of the data.

Published in Gilbert, G.S., S.G. Carvill, A.R. Krohn, and A.S. Jones. 2024. Three censuses of a mapped plot in coastal California mixed-evergreen and redwood forest. Forests 15: 164; https://doi.org/10.3390/f15010164

Descriptions of each of the values included in the data:

quadrat: Southwest corner of 20x20-m quadrat, designate in meters E and N of the southwest corner of the FERP. E.g., E080_N160 is 80 m east and 160 m north of the southwest corner.

tag: Unique number for each individual tree, shrub, or liana with diameter larger than 1 cm. Tags are pre-stamped aluminum tags with sequential numbers from 1 through 37985. Tags for smaller individuals are tied to the base of the tree using horticultural tape; for larger trees, tags are nailed into the trunk at 2 m height on the north side of the tree.

stemtag: Number that designates separate stems within a multistem individual. The stem with the tag is considered stemtag 1, but does not receive a physical tag. Each additional stem larger than 1 cm diameter receives a write-on aluminum tag sequentially numbered, beginning with 2 within each individual, tied near the base of the stem. Stemtags were given to stems beginning in the FERP2 census.

stemtag1: For FERP1, each stem of multistem individuals was measured, but was not given a physical stemtag. These numbers are sequential, post-hoc numbers, beginning at 102 within each individual, to designate each of the stems within a multistem individual. It is not possible to confidently make a direct correspondence between a particular stem of multistem individual in FERP1 and a stem with a stemtag in FERP2.

code6: Six-letter code designating the plant species. In general, the code is the first 4 letters of the genus and first 2 letters of the species epithet. For species with taxonomic name changes after the FERP1 census, the original code6 was retained for consistency. Species names are as follows: ACERMA Acer macrophyllum Pursh; ADENFA Adenostoma fasciculatum Hook. & Arn.; ARBUME Arbutus menziesii Pursh; ARCTAN Arctostaphylos andersonii A. Gray; ARCTCR Arctostaphylos crustaceae Eastw.; BACCPI Baccharis pilularis DC.; CEANTH Ceanothus thyrsiflorus Eschsch.; CORYCO Corylus cornuta subsp. californica Marshall (A.DC.) A.E.Murray; COTOFR Cotoneaster franchetii Bois; COTOPA Cotoneaster pannosus Franch.; CRATMO Crataegus monogyna Jacq.; ERIOJA Eriobotrya japonica (Thunb.) Lindl.; EUCAGL Eucalyptus globulus Labill.; RHAMCA Frangula californica (Eschsch.) A.Gray; HEDEHE Hedera helix L.; HETEAR Heteromeles arbutifolia (Lindl.) M.Roem; ILEXAQ Ilex aquifolium L.; LONIHI Lonicera hispidula (Lindl.) Douglas ex Torr. & A.Gray; MORECA Morella californica (Cham.) Wilbur; LITHDE Notholithocarpus densiflorus (Hook. & Arn.) Manos, C.H. Cannon & S.H.Oh; PINUAT Pinus attenuata Lemmon; PINUPO Pinus ponderosa var. pacifica J.R.Haller & Vivrette; PSEUME Pseudotsuga menziesii (Mirb.) Franco; PYRAAN Pyracantha angustifolia C.K.Schneid; QUERAG Quercus agrifolia Née; QUERPA Quercus parvula var. shrevei (C.H.Mull.) Nixon; RHODOC Rhododendron occidentale (Torr. & A.Gray) A.Gray; RIBEDI Ribes divaricatum Douglas; SALILA Salix lasiandra Benth.; SAMBNI Sambucus caerulea Raf.; SEQUSE Sequoia sempervirens (D.Don) Endl.; TOXIDI Toxicodendron diversilobum Greene; UMBECA Umbellularia californica (Hook. & Arn.) Nutt.; VACCOV Vaccinium ovatum Pursh.

east_m: Number of meters east (magnetic) of the western border of the FERP

north_m: Number of meters north (magnetic) of the southern border of the FERP

east_UTM: Easting UTM coordinates (zone 10, WGS84)

north_UTM: Northing UTM coordinates (zone 10, WGS84)

dsh1_mm: Diameter (in mm) at standard height (1.3 m) of stem in FERP1 census. Missing data indicate stem was not included in FERP1 census and was measured in later censuses.

dsh2_mm: Diameter (in mm) at standard height (1.3 m) of stem in FERP2 census. Missing data indicate stem was not either not yet included in census and was first measured in census FERP3, or it was dead or missing after including in FERP1 census, in which case status 2 would indicate “dead”. If status 2 indicates “nodata”, measurement of stem was inadvertently missed.

dsh3_mm: Diameter (in mm) at standard height (1.3 m) of stem in FERP3 census. Missing data stem was dead or missing after first inclusion in FERP1 or FERP 2 census, in which case status3 would indicate “dead”. If status3 indicates “nodata”, measurement of stem was inadvertently missed.

dsh1m_mm: Diameter (in mm) at standard height (1.3 m) of untagged multistems in FERP1 census. Used for stems designated with stemtag1. Missing data indicate this stem was not included in the FERP1 census.

date1: Date of observation in FERP1 census. Missing data indicate stem was not included until a later census.

date2: Date of observation in FERP2 census. Missing data indicate either that the stem was first mapped in the FERP3 census, or if status2 indicates “nodata”, observation of the stem was inadvertently missed.

date3: Date of observation in FERP3 census. Missing data indicate either that the stem was declared missing or dead in FERP2 census as indicated by status2, or if status3 indicates “nodata”, observation of the stem was inadvertently missed.

status1: Indicated as “living” if stem was mapped and measured in the FERP1 census. Missing data indicate stem was not included until a later census.

condition1: Observation of status of stem during FERP1 census:
“broken1.3” indicates stem is alive, but broken below the standard height for measurement of 1.3m
“leaning” indicates living trunk is leaning more than 30° off vertical
“prostrate” indicates stem is lying on the ground\
Missing data indicate that none of these attributes were applicable.

status2: Survival status of stems in FERP2 census.
“living” indicates stem was observed alive in the FERP2 census
“dead” indicates stem that was alive in FERP1 census, but found dead or missing in FERP2
“nodata” indicates a missing observation in FERP2 for stems alive in FERP1
Missing data indicate stem was not included until FERP3 census.

condition2: Observation of status of stem during FERP2 census:
“broken1.3” indicates stem is alive, but broken below the standard height for measurement of 1.3m
“leaning” indicates living trunk is leaning more than 30° off vertical
“prostrate” indicates living stem is lying on the ground\
“fallen” indicates the stem was found dead and found lying on the ground
“standing” indicates the stem was found dead and erect
“resprout” indicates the original stem was dead, with a living resprout not large enough to measure\
“missing” indicates stems tagged in FERP1 could not be located after diligent search
“Tagonly” indicates aluminum tag was found not attached to a stem, and stem could not be found.
Missing data indicate that none of these attributes were applicable.

status3: Survival status of stems in FERP3 census.
“living” indicates stem was observed alive in the FERP3 census
“dead” indicates stem that was alive in FERP2 census, but found dead or missing in FERP3
“nodata” indicates a missing observation in FERP3 for stems alive in FERP2
Missing data indicate that the stem was declared missing or dead in FERP2 census as indicated by status2.

condition3: Observation of status of stem during FERP3 census:
“broken1.3” indicates stem is alive, but broken below the standard height for measurement of 1.3m
“leaning” indicates living trunk is leaning more than 30° off vertical
“prostrate” indicates living stem is lying on the ground\
“fallen” indicates the stem was found dead and found lying on the ground
“standing” indicates the stem was found dead and erect
“missing” indicates stems tagged in FERP1 could not be located after diligent search
Missing data indicate that none of these attributes were applicable.

first_census: The first census (1, 2, or 3) at which the stem was measured.

irreg_dsh: Designates “irreg_dsh” if diameter measurement was made at a height other than the standard 1.3 m. Missing data indicate tree was measured at standard height of 1.3 m.

hom_m: Height in m at which diameter was measured. Standard height is 1.3 m from the highest location the ground meets the stem.

multi1: “multi1” indicates the individual had multiple stems larger than 1 cm diameter in FERP1. Missing data indicates this individual was not a multistem plant during that census.

stems1: Total number of stems in a multistem individual that were measured in FERP1. Missing data indicates this individual was not a multistem plant during that census or that it was not included until a later census.

multi2: “multi2” indicates the individual had multiple stems larger than 1 cm diameter in FERP2. Missing data indicates this individual was not a multistem plant during that census or that it was not included until a later census.

multi3: “multi3” indicates the individual had multiple stems larger than 1 cm diameter in FERP3. Missing data indicates this individual was not a multistem plant during that census, or that it had been declared dead or missing in FERP2 as indicated by status2.
basalarea1_m2: For FERP1 only, the total basal area of all measured stems of an individual, in units of m2

code6fix: Notes that indicate that a stem identification in one census was corrected in a subsequent census. Missing data indicate there were no relevant notes for that observation.

locfix: Indication that original mapping location of stem was in error, and was fixed in a subsequent census. “loc_fixed” indicates the stem was physically re-mapped to the correct location. “loc_rand_inQ” was used for 70 individuals (90 stems) for which location coordinates are missing, but for which the 20x20-m quadrat is known. For those stems, random easting and northing coordinates within the quadrat were assigned. Missing data indicate there were no relevant notes for that observation.

notes2: Field notes indicating irregularities found in FERP2 census. Missing data indicate there were no relevant notes for that observation.

notes3: Field notes indicating irregularities found in FERP3 census. Missing data indicate there were no relevant notes for that observation.

Research domain:

1.6 Biological sciences – Plant sciences, Ecology

Keywords:

Forest dynamics plot, ForestGEO, forest ecology, trees, shrubs, lianas, redwood forest, mixed evergreen forest, California, Douglas-fir, coast live oak, tanoak, coast redwood, Pseudotsuga, Quercus, Notholithocarpus, Arbutus, Sequoia, Mediterranean climate

Funding information:

This research was funded by the National Science Foundation, grant numbers DEB-0515520, DEB-0842059, DEB-1136626, DEB-1655896, the Pepper-Giberson Chair in Environmental Studies, the Robert Headley Presidential Chair for Integral Ecology and Environmental Justice, the UCSC Campus Natural Reserve, the UCSC Committee on Research, the UCSC Center for Teaching Excellence, and the Smithsonian Institute's Center for Tropical Forest Science (CTFS). The UCSC-FERP is part of the Smithsonian ForestGEO network of mapped forest plots.

Methods:

Methods are as described in the manuscript in Forests and in Gilbert et al. 2010. Beyond the tropics: forest structure in a temperate forest mapped plot. Journal of Vegetation Science 21:388-405. https://doi.org/10.1111/j.1654-1103.2009.01151.x