Tree, understory, soil, and light data for Hakalau Forest National Wildlife Refuge, Hawaiʻi Island, 2016-2020

Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: Yelenik, Stephanie G.
Originator: D'Antonio, Carla M.
Originator: Rehm, Evan M.
Originator: Elgersma, Cheryl
Publication_Date: 2024
Title:
Tree, understory, soil, and light data for Hakalau Forest National Wildlife Refuge, Hawaiʻi Island, 2016-2020
Geospatial_Data_Presentation_Form: tabular digital data
Publication_Information:
Publication_Place: Fort Collins, CO
Publisher: Forest Service Research Data Archive
Online_Linkage: https://doi.org/10.2737/RDS-2024-0036
Description:
Abstract:
This data publication includes tree and shrub basal area, grass biomass, soil nitrogen and carbon pools and fluxes under Acacia koa and Metrosideros polymorpha trees in mid-elevation old pasture sites on Hawaiʻi Island in the Hakalau Forest National Wildlife Refuge from 2016 to 2020. Additional data include grass biomass, soil nitrogen and organic matter, and light levels in experimental understory plantings in Acacia koa forest from nearby sites during the same time period.
Purpose:
These data were collected to better understand the role of forest understory regeneration on soil nutrient dynamics, light levels, and how these factors can lead to tipping points in lowering invasive grass biomass in secondary forests in old pasture sites. Alternative stable equilibrium theory hypothesizes that a system can exist as multiple stable-states under the same environmental conditions. The current state is determined by priority effects and is non-transitory due to the positive feedbacks between the community and the environment. Only when certain thresholds are met do systems experience phase shifts from one stable-state to an alternative. Understanding where these thresholds are is important for restoration and management because it helps managers predict the level of resources needed to push an ecosystem from a degraded state to a more desired condition. We addressed thresholds to soil and light variables that are known to affect native plant regeneration by surveying for these variables under a range of natural and planted understory basal area.
Supplemental_Information:
For more information about this study and these data, see D'Antonio et al. (2024).
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20161001
Ending_Date: 20200901
Currentness_Reference:
Ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
All data were taken in Hakalau Forest National Wildlife Refuge, Hawaiʻi Island.
Bounding_Coordinates:
West_Bounding_Coordinate: -155.33432
East_Bounding_Coordinate: -155.26360
North_Bounding_Coordinate: 19.86812
South_Bounding_Coordinate: 19.77187
Bounding_Altitudes:
Altitude_Minimum: 1600
Altitude_Maximum: 2000
Altitude_Distance_Units: meters
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: environment
Theme:
Theme_Keyword_Thesaurus: National Research & Development Taxonomy
Theme_Keyword: Ecology, Ecosystems, & Environment
Theme_Keyword: Plant ecology
Theme_Keyword: Soil
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: canopy tree effects
Theme_Keyword: invasive grasses
Theme_Keyword: nitrogen fixation
Theme_Keyword: nitrogen mineralization
Theme_Keyword: nitrification
Theme_Keyword: forest understory
Theme_Keyword: restoration
Theme_Keyword: reforestation
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Hawai'i
Place_Keyword: Hawaii
Place_Keyword: Hakalau Forest National Wildlife Refuge
Taxonomy:
Keywords/Taxon:
Taxonomic_Keyword_Thesaurus:
None
Taxonomic_Keywords: multiple species
Taxonomic_Keywords: plants
Taxonomic_Keywords: Acacia koa
Taxonomic_Keywords: Metrosideros polymorpha
Taxonomic_Keywords: Cenchrus clandestinus
Taxonomic_Keywords: Ehrharta stipoides
Taxonomic_Keywords: Cheirodendron trigynum
Taxonomic_Keywords: Coprosma rhynchocarpa
Taxonomic_Keywords: Ilex anomala
Taxonomic_Keywords: Myrsine lessertiana
Taxonomic_Keywords: Vaccinium calycinum
Taxonomic_System:
Classification_System/Authority:
Classification_System_Citation:
Citation_Information:
Originator: ITIS
Publication_Date: 2024
Title:
Integrated Taxonomic Information System
Geospatial_Data_Presentation_Form: database
Other_Citation_Details:
[accessed on June 24, 2024]
Online_Linkage: https://www.itis.gov/
Taxonomic_Procedures:
Taxonomic_Classification:
Taxon_Rank_Name: Kingdom
Taxon_Rank_Value: Plantae
Applicable_Common_Name: plantes
Applicable_Common_Name: Planta
Applicable_Common_Name: Vegetal
Applicable_Common_Name: plants
Taxonomic_Classification:
Taxon_Rank_Name: Subkingdom
Taxon_Rank_Value: Viridiplantae
Applicable_Common_Name: green plants
Taxonomic_Classification:
Taxon_Rank_Name: Infrakingdom
Taxon_Rank_Value: Streptophyta
Applicable_Common_Name: land plants
Taxonomic_Classification:
Taxon_Rank_Name: Superdivision
Taxon_Rank_Value: Embryophyta
Taxonomic_Classification:
Taxon_Rank_Name: Division
Taxon_Rank_Value: Tracheophyta
Applicable_Common_Name: vascular plants
Applicable_Common_Name: tracheophytes
Taxonomic_Classification:
Taxon_Rank_Name: Subdivision
Taxon_Rank_Value: Spermatophytina
Applicable_Common_Name: spermatophytes
Applicable_Common_Name: seed plants
Applicable_Common_Name: phanérogames
Taxonomic_Classification:
Taxon_Rank_Name: Class
Taxon_Rank_Value: Magnoliopsida
Taxonomic_Classification:
Taxon_Rank_Name: Superorder
Taxon_Rank_Value: Asteranae
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Ericales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Ericaceae
Applicable_Common_Name: heaths
Applicable_Common_Name: éricacées
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Vaccinium
Applicable_Common_Name: blueberries
Applicable_Common_Name: huckleberry
Applicable_Common_Name: blueberry
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Vaccinium calycinum
Applicable_Common_Name: ohelo kau la'au
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Primulaceae
Applicable_Common_Name: primroses
Applicable_Common_Name: primevères
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Myrsine
Applicable_Common_Name: colicwood
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Myrsine lessertiana
Applicable_Common_Name: kolea lau nui
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Gentianales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Rubiaceae
Applicable_Common_Name: madders
Applicable_Common_Name: rubiacées
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Coprosma
Applicable_Common_Name: mirrorplant
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Coprosma rhynchocarpa
Applicable_Common_Name: woodland mirrorplant
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Apiales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Araliaceae
Applicable_Common_Name: ginseng
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Cheirodendron
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Cheirodendron trigynum
Applicable_Common_Name: olapalapa
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Aquifoliales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Aquifoliaceae
Applicable_Common_Name: hollies
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Ilex
Applicable_Common_Name: hollies
Applicable_Common_Name: holly
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Ilex anomala
Applicable_Common_Name: Hawai'i holly
Taxonomic_Classification:
Taxon_Rank_Name: Superorder
Taxon_Rank_Value: Lilianae
Applicable_Common_Name: monocots
Applicable_Common_Name: monocotyledons
Applicable_Common_Name: monocotylédones
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Poales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Poaceae
Applicable_Common_Name: grasses
Applicable_Common_Name: graminées
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Cenchrus
Applicable_Common_Name: sandbur
Applicable_Common_Name: fountaingrass
Applicable_Common_Name: Kikuyu grass
Applicable_Common_Name: kikuyugrass
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Cenchrus clandestinus
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Ehrharta
Applicable_Common_Name: veldtgrass
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Ehrharta stipoides
Applicable_Common_Name: meadow ricegrass
Applicable_Common_Name: weeping grass
Taxonomic_Classification:
Taxon_Rank_Name: Superorder
Taxon_Rank_Value: Rosanae
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Myrtales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Myrtaceae
Applicable_Common_Name: myrtles
Applicable_Common_Name: myrtacées
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Metrosideros
Applicable_Common_Name: lehua
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Metrosideros polymorpha
Applicable_Common_Name: 'ohi'a lehua
Taxonomic_Classification:
Taxon_Rank_Name: Order
Taxon_Rank_Value: Fabales
Taxonomic_Classification:
Taxon_Rank_Name: Family
Taxon_Rank_Value: Fabaceae
Applicable_Common_Name: peas
Applicable_Common_Name: legumes
Taxonomic_Classification:
Taxon_Rank_Name: Genus
Taxon_Rank_Value: Acacia
Taxonomic_Classification:
Taxon_Rank_Name: Species
Taxon_Rank_Value: Acacia koa
Applicable_Common_Name: koa
Access_Constraints: None
Use_Constraints:
These data were collected using funding from the U.S. Government and can be used without additional permissions or fees. If you use these data in a publication, presentation, or other research product please use the following citation:

Yelenik, Stephanie G.; D'Antonio, Carla M.; Rehm, Evan M.; Elgersma, Cheryl. 2024. Tree, understory, soil, and light data for Hakalau Forest National Wildlife Refuge, Hawaiʻi Island, 2016-2020. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2024-0036
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA Forest Service, Rocky Mountain Research Station
Contact_Person: Stephanie G. Yelenik
Contact_Position: Rangeland Scientist
Contact_Address:
Address_Type: mailing and physical
Address: 920 Valley Road
City: Reno
State_or_Province: NV
Postal_Code: 89503
Country: USA
Contact_Voice_Telephone: 775-784-7020
Contact_Electronic_Mail_Address: stephanie.yelenik@usda.gov
Contact Instructions: This contact information was current as of original publication date. For current information see Contact Us page on: https://doi.org/10.2737/RDS.
Data_Set_Credit:
Funding for this project was provided by the National Science Foundation (DEB 1557177); the U.S. Geological Survey; the USDA Forest Service, Rocky Mountain Research Station; and the USDA Forest Service, Northern Research Station.


Author Information:

Stephanie G. Yelenik
USDA Forest Service, Rocky Mountain Research Station
https://orcid.org/0000-0002-9011-0769

Carla M. D'Antonio
University of California, Santa Barbara

Evan M. Rehm
USDA Forest Service, Northern Research Station
https://orcid.org/0000-0002-5804-0027

Cheryl Elgersma
University of California, Santa Barbara
Cross_Reference:
Citation_Information:
Originator: D'Antonio, Carla M.
Originator: Rehm, Evan M.
Originator: Elgersma, Cheryl
Originator: Yelenik, Stephanie G.
Title:
Influence of native woody understory on invasive grasses and soil nitrogen dynamics under plantation and remnant montane tropical trees
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Ecosystems
Issue_Identification: 27: 797–814
Online_Linkage: https://doi.org/10.1007/s10021-024-00922-z
Online_Linkage: https://research.fs.usda.gov/treesearch/68136
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
We did do quality assurance and quality control checks to correct any data entry issues.
Logical_Consistency_Report:
The data are logically consistent. The consistency was verified as part of the quality assurance that occurred during data analysis.
Completeness_Report:
Missing data noted as 'NA'. Values of 0 represent actual measurements of zero.
Lineage:
Methodology:
Methodology_Type: Field
Methodolgy_Identifier:
Methodolgy_Keyword_Thesaurus:
None
Methodology_Keyword: substrate induces respiration
Methodology_Keyword: nitrification potential
Methodology_Keyword: nitrogen mineralization incubations
Methodology_Keyword: loss on ignition
Methodology_Description:
STUDY SITE

Hakalau Forest National Wildlife Refuge is a 13,240-hectare (ha) high elevation tract on the windward side of Hawaiʻi Island, USA. The area receives approximately 2700 millimeters (mm) of rainfall annually (Giambelluca et al. 2013). The refuge includes intact forest at lower elevations (less than 1600 meters above sea level), and large areas (approximately 2000 ha) where forest was cleared. The intact forest is dominated by Metrosideros polymorpha (referred to as RO for “remnant ʻōhiʻa”) with Acacia koa (AK) as the second most abundant canopy tree. Clearing for livestock occurred in the 1800s with some remnant M. polymorpha trees left within pastures. The U.S. National Fish and Wildlife Service (USFWS) purchased the land in the 1980s, fenced and removed ungulates in the early 1990s, and planted corridors of AK to initiate forest recovery and facilitate development of endangered bird habitat. Yet the understory of the AK corridors remains dominated by two introduced (African) perennial grasses, Cenchrus clandestinus (kikuyu) and Ehrharta stipoides (meadow rice grass). Few native species have naturally recruited into the understory of these AK corridors. As a result, over the past 15 years, the USFWS has begun to outplant a variety of understory species including Cheirodendron trigynum, Coprosma rhynchocarpa, Ilex anomala, Myrsine lessertiana and Vaccinium calycinum. Metrosideros polymorpha is also sometimes planted into this understory, as is Leptocophylla tameiameia, an understory dominant in the intact forest. While we do not know the precise planting time of locations of understory plantings due to a lack of records, we chose sites where planted understory was at least 8 years old based on plant size and our familiarity with plant growth rates. These approximate dates were corroborated by USFWS personnel.

In contrast to the dense grass under AK trees, RO trees vary in their understory composition from almost 100% non-native grass cover to dense halos of native shrubs extending to and sometimes beyond the edge of the RO tree canopy. These shrubs have recruited since the removal of ungulates. Common halo understory species include many of those currently being used in understory outplanting efforts.

Soils across the refuge are acidic andisols of the Laupahoehoe Volcanic series (Peterson and Moore 1987). The surface soils are well-drained loams and typically have high organic matter. They overlay basalt lava flows that are between 10,000-20,000 years old (Scowcroft et al. 2004).


FOCAL TREE AND SAMPLE SITE SELECTION

During October 2016 through February 2017, we conducted an initial tree survey along transects established in 1985 by USFWS for annual bird point-counts. At each station (every 200 meters [m]) we located nearby potential focal trees of the two canopy types (RO or AK). For RO, we attempted to locate trees outside of AK corridors to isolate species-specific canopy effects. We visually estimated percent cover of understory species within a 5-m radius of the focal tree and then chose a non-random subset of twenty of each of these tree-centered plots stratified to ensure overstory tree types were spread across the refuge and to be representative of a gradient of woody understory density under each canopy species.

Understory woody plants in AK sites were from plantings since there is no natural recruitment under AK trees there. By contrast the understory woody plants in all RO sites were ‘naturally recruited’ since there is no active planting under RO. Soil from six ‘open grassland’ (OP) sites was sampled as a comparison to tree-covered plots. Open sites were more than 20 m from any tree and had to have no A. koa root suckers or woody plants in a 100 m² area around the center point. We included fewer open sites because it was difficult to find ones without A. koa root suckers from nearby AK, or that were not on rocky topography or covered with dense invasive Rubus argutus (Florida raspberry). OP sites are meant to be representative of abandoned pasture soil conditions without restoration.


VEGETATION AND SOIL SAMPLING

At each chosen focal tree or OP central point we set out 5 m radius transects with the tree as the center point (78.5 m²). We surveyed all woody plants placing each plant encountered into a basal diameter size class identified to species. Grass cover was visually estimated. To sample the grass and litter biomass, we placed 1 m × 0.5 m quadrats 2.5 m away from the central plot point in each cardinal direction. We harvested all grass biomass in the quadrat and separated out plant litter down to the soil surface which was considered to be soil without recognizable leaves. The grasses and plant litter were weighed in the field and a subsample of each returned to the lab to be dried for conversion of field wet weights to dry biomass. Subsamples were ground through 20 mm Wiley mesh and a Wig-L-bug (Crescent Dental) and analyzed for percent carbon (C) and percent nitrogen (N) on a Fison’s CN analyzer at the University of Hawaiʻi, Hilo Analytical Lab. The four values for each tree were averaged for one value per tree.

We also took two 15 centimeter (cm) deep, 2.5 cm wide soil cores in each quadrat. The 4 cores per focal tree were combined into one bag for a single composite sample. Samples were transported to the lab in coolers and sieved through 2 mm mesh. Soil organic content was estimated on dry subsamples from each site by measuring the loss of weight after ignition (Loss On Ignition, hereafter LOI) in a 550 degrees Celsius (°C) muffle furnace for 5 hours. LOI values are presented as raw values since we did not establish a carbon correction factor. Yet we consider them indicative of soil organic matter in these low clay surface soils.


SHORT TERM N AVAILABILITY

We used two methods to determine short-term N availability: (1) A five day lab resin capsule incubation (hereafter, resinN), and (2) a roughly one month (26 days) aerobic laboratory incubation (short term netmin). For resinN, 35-40 grams (g) of field moist soil was wetted with dionized (DI) water to form a paste following methods from Unibest (https://www.unibestinc.com/technology). Then a Unibest resin capsule was inserted into the paste and incubated for 5 days in the dark at room temperature (22°C) in Volcano, Hawaiʻi. Retrieved resin capsules were washed with a forceful stream of DI water and then dripped with 2N HCl as per Unibest recommendations. The extracted solutions were analyzed for NH4 and NO3 at the UHH Analytical lab. Values were converted from parts per million to milligrams of mineral N captured per g resin per day. These HCl extracts were also analyzed by Unibest for other associated ions (data not reported here). Three outlier values (no nutrients recovered) were deleted. For short term netmin, sieved soils were wetted to 70% of water holding capacity (WHC) (determined in the lab with funnel method) and allowed to incubate in a ziploc bag for two days at room temperature in the dark before a time zero (T0) sample was taken. At that time 10 g of soil was placed into a tin and dried overnight at 100°C for gravimetric water determination. 20 g were extracted immediately with 2M KCl for T0 N, and an additional 20 g were placed into a specimen cup, covered and incubated for 26 days at 20-22°C in the dark in Volcano, Hawaiʻi. After 26 days samples were extracted with 2M KCl. Extractants were analyzed for NH4 and NO3 at the UHH Analytical lab with a Lachat 8500 Quickchem. Short term netmin was calculated as T1 (NH4 + NO3) - T0 (NH4 + NO3) divided by the dry weight of incubated soil.


LONG TERM N TRANSFORMATION, NITRIFICATION POTENTIAL AND MICROBIAL BIOMASS

To measure long term ability of soils to mineralize N, we shipped sieved soils in coolers to the University of California, Santa Barbara (UCSB), where they were kept in a walk-in refrigerator for about three weeks. Soils were then divided into multiple 10-g subsamples placed into falcon tubes and incubated in mason jars at 22°C on a 12:12 light dark cycle for 5 months. N mineralization was measured by taking a Tinitial sample and samples at one, two, four and five months. Sampling involved extraction with 2M KCl, as well as measurement of 24-hour soil respiration rates using a Licor-C02 gas analyzer prior to KCl extraction.

We measured the relative size of the microbial nitrifier community via a nitrification assay. Each sample’s nitrification potential was assessed using a chlorate slurry inhibition assay (Belser and Mays 1980) in which we incubated 5 g of moist soil for 6 hours in a solution containing 0.2 molarity (M) dipotassium phosphate (K2HPO4), 0.2 M monopotassium phosphate (KH2PO4), and 0.2 M ammonium sulfate ((NH4)2SO4). The goal was to provide abundant substrate to microbes to maximize nitrification rates, while blocking oxidation of nitrite to nitrate with 1 M sodium chlorate (NaClO3). We determined NO2 concentrations with a colorimetric assay at hours 0, 3 and 6 and estimated nitrification potential using the rate of increase in NO2- over the course of the assay. The assay was conducted after the soils had incubated for 2 months at UCSB.

To measure microbial biomass, we used a substrate-induced respiration (SIR) assay following Fierer et al. (2003). It was done on soil subsamples from the same bulk samples on which nitrification potential measurements were made two months after the beginning of the incubation. The method relies on measuring the response of microbes to an excess of labile C as yeast. Approximately 5 g soil were incubated with the yeast after which CO2 efflux rates were measured at T0 (10 minutes post yeast addition), and approximately 2 and 4 hours later by injecting gas from the headspace of each jar into a Licor IRGA. Conversion of CO2 efflux rates to an index of SIR was done following Fierer et al. (2003).


EXPERIMENTAL UNDERSTORY DENSITY TREATMENTS

To evaluate experimentally how understory planting density affects grass biomass and soil properties, we planted understory species commonly used in restoration at Hakalau Forest around single AK trees with no previous outplanting. We selected sets of trees at seven sites that were at least 100 m apart from each other and applied three treatments: control, single density and double density. For the single density planting treatment, seedlings of 5 species of woody plants including four C. trigynum (ʻōlapa), four C. rhynchocarpa (pilo), three M. lessertiana (kōlea), three V. calycinum (ʻōhelo) and two I. anomala (kāwaʻu) were outplanted around focal AK with 16 individual plants planted into a roughly 28 m² area (0.57 stem/m²). This is almost 3 times the planting density currently used by the USFWS. For the high-density planting treatment, seedlings were planted at twice this density (1.14 stems/m²). The highest density we could find in USFWS outplanting was 0.65 stems/m². For examples of how these plantings look see Figure S1-b in D'Antonio et al. (2024). Two of the species (ʻōlapa and pilo) were planted in July 2016, and the rest in October 2016, due to differential germination times and growth rates (see Yelenik et al. 2022). The understory of all trees was initially dominated by kikuyu grass with no woody seedlings or saplings. Plant height averaged 40 cm. The mix of species was typical of those found naturally recruiting around RO. Nitrogen availability and grass biomass were sampled immediately prior to outplanting and found to not be different between the plots assigned to different treatments (Yelenik et al. 2022).

In September 2020, we harvested grass and standing woody litter to the soil surface in two 0.5 m × 0.5 m quadrats per AK tree as well as at one nearby AK tree within 10 m that did not have understory plantings as a control (n=7). Clipped plots were located at 0.5 m north and east of the focal AK. We then collected soil by taking one 3.8 cm diameter by 10 cm deep soil cores from both clipped plots, bulked the two cores into one sample per tree, and sieved cores through 2 mm mesh. We extracted 10 g of sieved soil with 50 mm of 2 M KCl for 1 hour and filtered extracts with a Whatman #1 filter. Extracts were analyzed at the UHH Analytical Lab for inorganic N (Lachat Quikchem 8500) and corrected for gravimetric soil moisture. We measured soil percentage of C and N on sieved soil. In August 2021 we collected light transmittance with a light wand (Apogee MQ-301 PAR Meter, Logan, Utah) at breast height, with the wand placed into the understory plantings (or a similar location at control trees) at each of the cardinal directions. We then took three points from a nearby location with no canopy to get a full sun reading and used the ratio of the understory to the average full sun reading for light transmittance (four readings per tree).
Methodology_Citation:
Citation_Information:
Originator: D'Antonio, Carla M.
Originator: Rehm, Evan M.
Originator: Elgersma, Cheryl
Originator: Yelenik, Stephanie G.
Title:
Influence of native woody understory on invasive grasses and soil nitrogen dynamics under plantation and remnant montane tropical trees
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Ecosystems
Issue_Identification: 27: 797–814
Online_Linkage: https://doi.org/10.1007/s10021-024-00922-z
Online_Linkage: https://research.fs.usda.gov/treesearch/68136
Methodology_Citation:
Citation_Information:
Originator: Belser, L.W.
Originator: Mays, E.
Publication_Date: 1980
Title:
Specific inhibition of nitrite oxidation by chlorate and its use in assessing nitrification in soils and sediments
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Applied and Environmental Microbiology
Issue_Identification: 39(3): 505-510
Online_Linkage: https://doi.org/10.1128/aem.39.3.505-510.1980
Methodology_Citation:
Citation_Information:
Originator: Fierer, Noah
Originator: Schimel, Joshua P.
Originator: Holden, Patricia A.
Publication_Date: 2003
Title:
Influence of drying–rewetting frequency on soil bacterial community structure
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Microbial Ecology
Issue_Identification: 45: 63-71
Online_Linkage: https://doi.org/10.1007/s00248-002-1007-2
Methodology_Citation:
Citation_Information:
Originator: Giambelluca, Thomas W.
Originator: Chen, Qi
Originator: Frazier, Abby G.
Originator: Price, Jonathan P.
Originator: Chen, Yi-Leng
Originator: Chu, Pao-Shin
Originator: Eischeid, Jon K.
Originator: Delparte, Donna M.
Publication_Date: 2013
Title:
Online rainfall atlas of Hawai‘i
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Bulletin of the American Meteorological Society
Issue_Identification: 94(3): 313-316
Online_Linkage: https://doi.org/10.1175/BAMS-D-11-00228.1
Methodology_Citation:
Citation_Information:
Originator: Peterson, Donald W.
Originator: Moore, Richard B.
Publication_Date: 1987
Title:
Geologic history and evolution of geologic concepts
Geospatial_Data_Presentation_Form: book chapter
Other_Citation_Details:
Chapter 7
Other_Citation_Details:
p. 149-189
Online_Linkage: https://pubs.usgs.gov/pp/1987/1350/
Larger_Work_Citation:
Citation_Information:
Originator: Decker, Robert W.
Originator: Wright, Thomas L.
Originator: Stauffer, Peter H.
Publication_Date: 1987
Title:
Volcanism in Hawaii
Geospatial_Data_Presentation_Form: document
Series_Information:
Series_Name: U.S. Geological Survey Professional Paper
Issue_Identification: 1350
Publication_Information:
Publisher: U.S. Geological Survey
Other_Citation_Details:
1667 p.
Methodology_Citation:
Citation_Information:
Originator: Scowcroft, Paul G.
Originator: Haraguchi, Janis E.
Originator: Hue, Nguyen V.
Publication_Date: 2004
Title:
Reforestation and topography affect montane soil properties, nitrogen pools, and nitrogen transformations in Hawaii
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Soil Science Society of America Journal
Issue_Identification: 68(3): 959-968
Online_Linkage: https://doi.org/10.2136/sssaj2004.9590
Methodology_Citation:
Citation_Information:
Originator: Yelenik, Stephanie G.
Originator: Rehm, Evan M.
Originator: D'Antonio, Carla M.
Publication_Date: 2022
Title:
Can the impact of canopy trees on soil and understory be altered using litter additions?
Geospatial_Data_Presentation_Form: journal article
Series_Information:
Series_Name: Ecological Applications
Issue_Identification: 32(1): e02477
Online_Linkage: https://doi.org/10.1002/eap.2477
Process_Step:
Process_Description:
see methodology section
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Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Below you will find a list and description of the files included in this data publication.


VARIABLE DESCRIPTION FILE (1)

1. \Data\_variable_descriptions.csv: Comma-separated values (CSV) file containing a list and description of variables found in all data files. (A description of these variables is also provided in the metadata below.)

Columns include:

Filename = name of data file
Variable = name of variable
Units = units (if applicable)
Precision = precision (if applicable)
Description = description of variable


DATA FILES (3)

1. \Data\Haka_all_soils_data_final.csv: CSV file containing soil and vegetation characteristics of 46 focal tree sample sites: 20 under Acacia koa (AK) trees, 20 under Remnant Ohia (RO) trees, and 6 in the open (OP).

Variables include:

sample ID = The unique identifier for each sampled location made up of a transect number, an abbreviation for tree type, and an individual tree number. There were 52 total sampled locations including 20 under AK (Acacia koa) trees, 20 under RO (Remnant Ohia) trees, 6 in the OP (open) and 6 under Remnant Koa (RK). These RK sites are not included in this data publication.

koa present = A categorical way of dividing sample locations by whether or not Acacia koa trees were present. (y = yes, n = no)

T0 N all = Total of ammonium and nitrate as determined by KCl extractions of samples collected from field corrected for field moisture. (Units: micrograms/gram)

short term net min lab = The result of a 26 day lab incubation followed by extraction of soils using 2 NKCl (similar to T0). Result is T final minus T0 for combined available nitrogen (N). (Units: micrograms/gram/day)

T0 NO3 = The value of nitrate in the KCl extracted soil sample. It is a subset of the value presented in column "T0 N all". (Units: micrograms/gram)

short term net nitr = The net amount of nitrate present in soil samples after a 26 day incubation. It is a subset of the short term net min in that it only includes nitrate (Tfinal minus T0). (Units: micrograms/gram/day)

Loss on ignition = The % change in soil weight from before versus after ignition in a muffle furnace. Measurement taken approximately 1 week after samples were collected. (Units: percentage)

resinN/day = The amount of ammonium and nitrate extracted from standardized ion exchange resin balls (Unibest) using HCl, after a 5 day lab incubation, divided by the number of days of incubation. (Units: micrograms/day)

Understory woody basal area (cm2) = The combined area of understory woody plants measured in the initial surveys of these sites (2017). It does not include blackberry/raspberry stems but otherwise includes all woody plant stems >1 centimeter in basal diameter within the sampled area around the target tree (or open) location. (Units: square centimeters)

#seedling = A numerical total of seedlings of woody plants that were too small to be included in understory woody basal area but indicated that woody plant seeds could be germinating in these sites. (Units: count)

litter N = The % N by weight in a mixed, ground sample of litter from under the given tree or in the open. All types of litter were combined and ground together first through a wiley mill and then with a wig-l-bug amalgumator. Samples were weighed into tin capsules and analyzed with a Fison’s CN analyzer. (Units: percentage)

soil N% = % N of a soil sample after sieving through 2 millimeter mesh, grinding with a mortar and pestel and then igniting the sample in a fison’s CN analyzer. (Units: percentage)

Focal tree basal = The surface area of the focal tree estimated by measuring the basal diameter and then using the area formula. (Units: square centimeters)

Total woody basal area (cm2) = The focal tree basal area (previous entry) plus the understory woody basal area. Represents the total area of woody species within the plot. (Units: square centimeters)

grass cov = The average percent cover of all grasses within 4 quadrats under each focal tree. Percent cover was estimated visually and then averaged across the 4 quadrats. Values are out of 100%. All species of grasses are combined into one estimate per quadrat. (Units: percentage)

CO2 resp = The total carbon dioxide (C02) respired during the sampled intervals during the 5 month lab incubation. (Units: parts per million)

Nit pot (lab-ucsb) = A direct measurement of the ability of microbes to transform ammonium into nitrate in a soil sample measured on soils in the lab approximately 3 months after field collection using chlorate slurry method. Values represent rate of increase of nitroxen dioxide (NO2) production over a 6 hour incubation and are per gram dry soil. (Units: parts per million)

microbial biomass by SIR = These values are as determined by the Substrate induced respiration methodology whereby microbial biomass (MB) is based on rates of CO2 production when soils are given excess labile carbon (C). Values are relative and not absolute. (Units: parts per million)

grass/m2 = This is the average dry biomass of grass across the four harvested quadrats within each plot. Field moisture wet measurements were corrected after drying subsamples of each grass sample in the lab. Values were then standardized to grams per square meter. (Units: grams/square meter)

long term netmin per day = The total net nitrogen mineralized across a 5 month incubation. T final [NH4+N03] minus T [NH4+N03] initial. (Units: nitrogen/gram soil/day)


2. \Data\Haka_Lt_netmin_intervals_final.csv: CSV file containing nitrogen availability at multiple time intervals from the start of incubation to 171 days later, at all 46 focal tree sample sites: 20 under AK trees, 20 under RO trees, and 6 in the OP.

Variables inlcude:

site = The unique identifier for each sampled location. There were 46 total sampled locations including 20 under AK trees, 20 under RO trees, and 6 in the open.

trt = A categorical variable that indicates whether the sample location was under a tree canopy (AK, RO) or in the open (OP).

T0 abs = The absolute value of mineral nitrogen (N) measured in the sample at the time of the start of the incubation. (Units: micrograms/gram dry soil)

T1 abs = This is the absolute value of mineral N measured in the sample 26 days after the start of the incubation. (Units: micrograms/gram dry soil)

T2 abs = This is the absolute value of mineral N measured in the sample 56 days after the start of the incubation. (Units: micrograms/gram dry soil)

T3 abs = This is the absolute value of mineral N measured in the sample 136 days after the start of the incubation (Units: micrograms/gram dry soil)

T4 abs = This is the absolute value of mineral N measured in the sample 171 days after the start of the incubation. (Units: micrograms/gram dry soil)

T1-T0 = Absolute value at T1 minus absolute value at T0. (Units: micrograms/gram dry soil)

min1/day = Previous column divided by number of days in the T1-T0 period. (Units: micrograms/gram/day)

T2-T1 = Absolute value at T2 minus absolute value at T1. (Units: micrograms/gram dry soil)

min2/day = Previous column divided by number of days in the T2-T1 period. (Units: micrograms/gram/day)

T3-T2 = Absolute value at T3 minus absolute value at T2. (Units: micrograms/gram dry soil)

min3/day = Previous column divided by number of days in the T3-T2 period. (Units: micrograms/gram/day)

T4-T3 = Absolute value at T4 minus absolute value at T3. (Units: micrograms/gram dry soil)

min4/day = Previous column divided by number of days in the T4-T3 period. (Units: micrograms/gram/day)

net abs T4-T0 = Ignores behavior of sample between individual times points and just subtracts T0 value from final (T4) value. (Units: micrograms/gram dry soil)

net whole time/day = Previous column divided by 171 days (total time of incubation) resulting in an average rate over entire period. (Units: micrograms/gram soil/day)


3. \Data\Soils_grass_biomass_light_compiled.csv: CSV file containing site characteristics (e.g., soils, leaf litter and grass biomass, and quantity of light) for 6 understory planting sites with multiple treatments and 1 control site.

Variables include:

site_no = Unique identifier for sites in which Acacia koa trees were located and sampled. There were 7 sites total.

treatment = Understory planting treatment implemented under focal koa trees in a circular plot with the focal tree at the center. (Planting 1x = 16 understory plants per 28 square meters; Planting 2x = 32 understory plants per 28 square meter; Control = no understory plants)

direction_light grass litter = Cardinal direction (North, South, East, West), in relation to focal tree trunk, at which light data, grass/litter biomass samples were taken.

%transmittance_v_open = Quantity of light getting through the tree and understory canopy expressed as a percentage of light in open sites with no canopy. (Units: percentage)

leaf litter biomass (g/m2) = Weight of dry woody litter biomass (leaves, twigs) found within 0.5 meter (m) × 0.5 m quadrats. (Units: grams/square meter)

grass biomass (g/m2) = Weight of dry grass biomass clipped within 0.5 m × 0.5 m quadrats. (Units: grams/square meter)

soil NO3-(µgN/g dry soil) = Nitrate content of soils. (Units: micrograms of nitrogen/gram)

soil NH4+(µgN/g dry soil) = Ammonium content of soils. (Units: micrograms of nitrogen/gram)

soil%OM = Organic matter of soils, expressed as a percent of total soil weight prior to burning off organic matter. (Units: percentage)

soil%Moisture = Soil moisture content of soils (“gravimetric moisture content”), expressed as a percent of total soil weight prior to burning off water. (Units: percentage)
Entity_and_Attribute_Detail_Citation:
D'Antonio, Carla M.; Rehm, Evan M.; Elgersma, Cheryl; Yelenik, Stephanie G. 2024. Influence of native woody understory on invasive grasses and soil nitrogen dynamics under plantation and remnant montane tropical trees. Ecosystems. 27: 797–814. https://doi.org/10.1007/s10021-024-00922-z and https://research.fs.usda.gov/treesearch/68136
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA Forest Service, Research and Development
Contact_Position: Research Data Archivist
Contact_Address:
Address_Type: mailing and physical
Address: 240 West Prospect Road
City: Fort Collins
State_or_Province: CO
Postal_Code: 80526
Country: USA
Contact_Voice_Telephone: see Contact Instructions
Contact Instructions: This contact information was current as of October 2024. For current information see Contact Us page on: https://doi.org/10.2737/RDS.
Resource_Description: RDS-2024-0036
Distribution_Liability:
Metadata documents have been reviewed for accuracy and completeness. Unless otherwise stated, all data and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. However, neither the author, the Archive, nor any part of the federal government can assure the reliability or suitability of these data for a particular purpose. The act of distribution shall not constitute any such warranty, and no responsibility is assumed for a user's application of these data or related materials.

The metadata, data, or related materials may be updated without notification. If a user believes errors are present in the metadata, data or related materials, please use the information in (1) Identification Information: Point of Contact, (2) Metadata Reference: Metadata Contact, or (3) Distribution Information: Distributor to notify the author or the Archive of the issues.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: CSV
Format_Version_Number: see Format Specification
Format_Specification:
Comma-separated values file
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: https://doi.org/10.2737/RDS-2024-0036
Fees: None
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Metadata_Reference_Information:
Metadata_Date: 20241030
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USDA Forest Service, Rocky Mountain Research Station, Maintaining Resilient Dryland Ecosystems Science Program
Contact_Person: Stephanie Yelenik
Contact_Position: Rangeland Scientist
Contact_Address:
Address_Type: mailing and physical
Address: 920 Valley Road
City: Reno
State_or_Province: NV
Postal_Code: 89512
Country: USA
Contact_Voice_Telephone: 805-451-5910
Contact_Electronic_Mail_Address: stephanie.yelenik@usda.gov
Contact Instructions: This contact information was current as of original publication date. For current information see Contact Us page on: https://doi.org/10.2737/RDS.
Metadata_Standard_Name: FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001.1-1999
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