This data set contains one data file (.csv format) that quantifies net primary productivity (NPP) as a function of rainfall in mesic to wet montane rainforests on the island of Maui, Hawaii, U.S.A. The NPP data were collected at six mature forests stands that comprise the Maui Moisture Gradient, a sequence of sites located on Maui where mean annual precipitation ranges from 2,200 mm to 5,050 mm while temperature and all other state factors (parent material, substrate age, organisms, and topography) that control NPP remain relatively constant.
Estimates are given for above-ground and below-ground productivity, and total NPP based on measurements made in 1996 and 1997. These data are part of a larger study that focused on the dynamics of carbon cycling and storage in everwet rainforest as a function of changes in rainfall regime.
The Hawaiian Islands flora and fauna are relatively species-poor, thus a few species and genera occupy a broad range of environmental conditions. As a result, the forest canopy at all sites was consistently dominated by the native evergreen tree Metrosideros polymorpha (Myrtaceae) which comprises 80% to 100% of basal area in these forests. The understory vegetation was dominated by a variety of ferns and other herbaceous species at all sites, but the dominance of particular understory species shifted among sites. This watershed area has never been cleared by humans.
Revision Notes: Only the documentation for this data set has been modified. The data files have been checked for accuracy and are identical to those originally published in 2005.
The Net Primary Productivity (NPP) data collection contains field measurements of biomass, estimated NPP, and climate data for terrestrial grassland, tropical forest, boreal forest, and tundra sites worldwide. Data were compiled from the published literature for intensively studied and well-documented individual field sites and from a number of previously compiled multi-site, multi-biome data sets of georeferenced NPP estimates. The principal compilation effort (Olson et al., 2001) was sponsored by the NASA Terrestrial Ecology Program. For more information, please visit the NPP web site at http://daac.ornl.gov/NPP/npp_home.html.
Cite this data set as follows:
Schuur, E.A.G. 2013. NPP Tropical Forest: Maui, Hawaii, U.S.A., 1996-1997, R1. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/802
This data set was originally published as:
Schuur, E.A.G. 2005. NPP Tropical Forest: Maui, Hawaii, U.S.A., 1996-1997.
Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National
Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Project: Net Primary Productivity (NPP)
The net primary productivity measurement presented here is sum of the increase in overstory biomass plus above-ground litterfall (together = ANPP) and below-ground root turnover (BNPP). Above-ground tree biomass was calculated using forest inventory and regression techniques. The investigators established a single 25 x 25 m productivity plot at each site and measured the diameter at breast height of all woody vegetation greater than 5 cm diameter. These measurements were converted to above-ground biomass using species-specific allometric equations derived from other studies in the Hawaiian Islands. Because the annual increment of growth was relatively small, dendrometer bands placed on a subset of ten trees were used to record the growth of trees. The average growth of trees with dendrometer bands was applied to the total basal area (> 5 cm dbh) of the study plot to estimate the biomass increment added on an annual basis. Litterfall was collected in 15 trays (0.156 m2) per site randomly placed on the forest floor and emptied at monthly intervals.
As an indirect measure of below-ground turnover, carbon dioxide fluxes from the soil surface were measured at monthly intervals over the period of a year. The surface flux of carbon dioxide consists of autotrophic root respiration plus heterotrophic decomposition of organic matter and has been used in ecosystems approaching equilibrium as a measure of C inputs. Therefore the investigators assumed that carbon released from the soil from heterotrophic respiration is approximately equivalent to the annual input of carbon entering the soil and, in combination with litterfall measurements, can be used as an index for below-ground NPP.
The data provided are estimates of the accumulation of biomass by plants for a given year, or net primary productivity (NPP). Estimates are given for above- and below-ground productivity, and the sum as net primary productivity. These data are part of a larger study that focused on the dynamics of carbon cycling and storage in everwet rainforest as a function of changes in rainfall regime.
ANPP, BNPP, and TNPP values reported in Clark et al. (2001a, b) differ from values presented herein due to different data sources and calculation methods (Table 1).
Table 1. ANPP, BNPP, and TNPP values reported by various published data sources
| File Name or Description | Data Source(s) | Sub-Site | ANPP | BNPP | TNPP |
|---|---|---|---|---|---|
| gC/m2/year | |||||
| MMG_NPP.csv | Schuur (2001)1
|
mmg 1
|
473.5 | 482.8 | 956.3 |
mmg 2 |
520.5 | 452.9 | 973.4 |
||
mmg 3 |
483.0 | 368.3 | 851.3 |
||
mmg 4 |
462.5 | 378.3 | 840.8 |
||
mmg 5 |
365.5 | 253.8 | 619.3 |
||
mmg 6 |
208.5 | 179.2 | 387.7 |
||
| Table 1 in Clark et al. (2001a) | Clark et al. (2001a)2 based on Raich et al. (1997)
|
USA: Hawaii, Site 5
|
140 | 30-170 (av 100) | 170-310 (av 240)
|
USA: Hawaii, Site 6
|
180 | 40-220 (av 130) | 220-400 (av 310)
|
||
| Appendix A in Clark et al. (2001a) | Clark et al. (2001a) based on Raich et al. (1997) |
Mauna Loa, Hawaii, Site 1
|
280 | NA | NA |
Mauna Loa, Hawaii, Site 2 |
200 | NA | NA |
||
Mauna Loa, Hawaii, Site 3 |
140 | NA | NA |
||
Mauna Loa, Hawaii, Site 4 |
30 | NA | NA |
||
Mauna Loa, Hawaii, Site 5 |
450 | NA | NA |
||
Mauna Loa, Hawaii, Site 6 |
290 | NA | NA |
||
| Appendix A in Clark et al. (2001a) | Clark et al. (2001a)2 based on Raich et al. (1997)
|
Mauna Loa, Hawaii, Site 5 |
NA | NA | 170-310 (av 240)3 |
Mauna Loa, Site 6 |
NA | NA | 220-400 (av 310)3 |
||
| tropfornpp.csv | Clark et al. (2001b)4 based on Raich et al. (1997)
|
USA-Hawaii-Site 1- 110 yr, 290 m |
102 | NA | NA |
| USA-Hawaii-Site 2- 136 yr, 700 m | 50 | NA | NA |
||
USA-Hawaii-Site 3- 136 yr, 1,130 m |
31 | NA | NA |
||
USA-Hawaii-Site 4- 136 yr, 1,660 m |
12 | NA | NA |
||
USA-Hawaii-Site 5- 3,400 yr, 700 m |
117 | NA | NA |
||
USA-Hawaii-Site 6- 3,400 yr, 1,660 m |
160 | NA | NA |
||
Notes: NA = Not available. The differences in NPP values reported in this table are mainly due to differences in calculation methods, as explained in these notes. Please consult original references for details. 1For this table, NPP data from the original data source were converted from megagrams of carbon per hectare per year to grams of carbon per meter square per year. The NPP estimate is based on the sum of the increase in overstory biomass + above-ground litterfall (together = ANPP) + below-ground root turnover (BNPP). 2Clark et al. (2001a) used a different approach to calculate net primary production values. ANPP was calculated by summing reported above-ground biomass increment + reported fine litterfall + estimated losses to consumers + estimated VOC emissions. BNPP was calculated by summing 0.2 x estimated ANPP for a low BNPP estimate + 1.2 x estimated ANPP for a high BNPP estimate. TNPP was calculated as the range between the low and high values of ANPP + BNPP. Average BNPP and TNPP estimates were also calculated. See Clark et al. (2001a) for a discussion of calculation methods, including how unmeasured components of ANPP were estimated and the basis for setting bounds on BNPP. 3In Appendix A of Clark et al. (2001a), these values are mislabeled as ANPP. 4Based on overstory litterfall plus above-ground biomass increment.
Site: Maui, Hawaii, U.S.A.
Site boundaries: (All latitude and longitude given in decimal degrees)
| Site (Region) | Westernmost Longitude | Easternmost Longitude | Northernmost Latitude | Southernmost Latitude | Elevation (m) |
|---|---|---|---|---|---|
| Maui, Hawaii, U.S.A. | -156.255278 | -156.229722 | 20.815139 | 20.805833 | 1,300 |
The plots are located along a moisture gradient (2,200 mm to 5,050 mm MAP) in areas that reasonably represented the local vegetation while keeping local factors such as parent material, substrate age, and topography constant among sites.
SITE |
MAP |
LATITUDE |
LONGITUDE |
Site 1 |
2,200 mm |
20.805833 N |
-156.255278 W |
Site 2 |
2,450 mm |
20.807361 N |
-156.252917 W |
Site 3 |
2,750 mm |
20.808333 N |
-156.25 W |
Site 4 |
3,350 mm |
20.813194 N |
-156.247083 W |
Site 5 |
4,050 mm |
20.813194 N |
-156.240278 W |
Site 6 |
5,050 mm |
20.815139 N |
-156.229722 W |
MAP = mean annual precipitation
Site Information
The Maui Moisture Gradient sites are located within a geographic distance of less then 5 km in the Makawao and Koolau Forest Reserves on the north flank of Haleakala volcano. Temperature regimes are similar at the constant altitude of the sites (approximately 1,300 m) while mean annual precipitation ranges systematically from 2,200 mm/yr (mesic) to over 5,000 mm/yr (wet) as a function of aspect relative to the prevailing trade winds. The sites are located on lava flows from the Kula volcanic series (mean age 410,000 years), which was part of the shield-building phase of Haleakala volcano. The original shield surface has been dissected by stream channels, so the study sites are located on shield volcano remnant surfaces on broad, flat (< 5 % slope) interfluve areas to minimize variation in local topography. The soils on this precipitation gradient are classified as Inceptisols and Andisols developed from lava with surface ash deposits.
The Hawaiian Islands flora and fauna are relatively species-poor, thus a few species and genera occupy a broad range of environmental conditions. As a result, the forest canopy at all sites was consistently dominated by the native evergreen tree Metrosideros polymorpha (Myrtaceae) which comprises 80% to 100% of basal area in these forests. The understory vegetation was dominated by a variety of ferns and other herbaceous species at all sites, but the dominance of particular understory species shifted among sites. This watershed area has never been cleared by humans and all six sites were located in mature forests stands.
The plot size was 25 x 25 m. The number of trees per hectare ranged from 1,104 to 2,352.
All measurements were made from 1996/01/01 to 1997/12/31.
All NPP measurements are based on plant dry matter accumulation and expressed on a annual basis (MgC/ha/yr).
Table 2. Data files in this data set archive
FILE NAME |
FILE SIZE |
TEMPORAL COVERAGE | FILE CONTENTS |
MMG_NPP.csv |
1 KB |
1996/01/01-1997/12/31 | NPP data for Maui Moisture Gradient Sites, Hawaii, U.S.A. |
NPP Data. NPP estimates for the Maui Moisture Gradient Sites are provided in one file (.csv format). There is no metadata and no missing values. All NPP measurements based on plant dry matter accumulation are expressed on a annual basis (Mg C/ha/yr).
Table 3. Column headings and parameter definitions
COLUMN HEADING |
DEFINITION |
UNITS |
Site |
Site identification number along moisture gradient |
numeric |
MAP |
Mean annual precipitation |
mm |
NPP |
Total net primary production |
MgC/ha/yr |
ANPP |
Above-ground net primary production |
|
BNPP |
Below-ground net primary production |
The accumulation of biomass, or NPP, is the net gain of carbon by photosynthesis that remains after plant respiration. While there are many fates for this carbon, this data set accounts for above-ground growth, leaf turnover, and root turnover. These are considered the major components of NPP.
The objective of this study was to quantify net primary productivity as a function of rainfall in mesic to wet montane rainforests in Maui, Hawaii. The Maui Moisture Gradient is a sequence of six sites located on the island of Maui where mean annual rainfall ranges from 2,200 mm to 5,050 mm while temperature and all other state factors (parent material, substrate age, organisms, and topography) that control NPP remain relatively constant. This data set contains annual estimates of net primary productivity made in 1996 and 1997.
This data set has been applied to a larger review of tropical forest NPP. See Schuur (2003).
The data provided are of generally good quality based on the site location and time frame. Data were examined for general consistency and clarity. Measurements were made under a variety of field conditions (rain mostly!) that presumably had little effect on the quality of measurements.
Sources of Error
The greatest potential source of error that other researchers need to be aware of for the Maui Moisture Gradient sites is the location of plots. The sites were stratified to keep state factors constant, so they may not represent NPP on larger scales with other factors such as local topography varying. Also, given that the measurements are presented on an annual basis, the amount of observation time (span of 2 years) is relatively short, although typical of many NPP studies.
Tree biomass. Above-ground tree biomass was calculated using forest inventory and regression techniques. Each site contained a single 25 x 25 m productivity plot where the diameter at breast height (dbh) of all woody vegetation greater than 5 cm diameter was measured. These measurements were converted to above-ground biomass using species-specific allometric equations derived from other studies in the Hawaiian Islands. For species other than M. polymorpha, allometries included tree height measured with an extension pole. Because tree heights were not available for all M. polymorpha trees, we used an allometric equation that relied on dbh alone. Finally, there were several large Acacia koa trees at Site 2 and 3. For these, a generalized wet forest allometric equation was used to estimate biomass for those individual trees because no species-specific allometric equation that includes A. koa trees of that size exists.
Above-ground net primary productivity. ANPP was estimated as the sum of increases in the above-ground biomass plus the litter production in the 25 x 25 m production plots established at each site. All litter was dried at 70 degrees C to obtain a consistent dry weight measurement. Litterfall was collected in 15 trays (0.156 m2) per site randomly placed on the forest floor and emptied at monthly intervals. Three sites (Sites 3, 5, 6) contained understory species whose litter production could not be collected with litter traps because senesced leaves did not fall to the forest floor. In Site 3 and Site 5, production of the fern Dicranopteris linearis (N.L. Burm.) Underw. (Gleicheniaceae) was measured by tagging 30 individual fronds, tagging new segments as they grew, and collecting and weighing the tagged frond segments that senesced during the study period. At 10 random points in each production plot we counted frond density in 1 x 1 m quadrats. Total litter production by D. linearis was calculated by multiplying the density of fronds by the annual litter produced by each frond. At Site 6, we measured the litter production of Carex alligata, an understory sedge, in a similar fashion. Leaves from 30 individual tillers were tagged as they grew, collected and weighed after they senesced, and multiplied by an estimate of tiller density.
Because the annual increment of growth is relatively small, aluminum, spring-loaded dendrometer bands were placed on a subset of ten trees randomly selected from all trees in the production plot. Growth increments were recorded at six month intervals over 18 months, starting after the bands had been allowed to settle on the trees for six months. The average growth of trees with dendrometer bands was applied to the total basal area (> 5 cm dbh) of the study plot to estimate the biomass increment added on an annual basis, using the regression equations previously described.
Below-ground Productivity. Carbon dioxide flux was measured from the soil surface at monthly intervals over the period of a year. Soil carbon dioxide fluxes from all measurement points were averaged to estimate an average daily efflux of carbon dioxide that incorporates seasonal fluctuations. The surface flux of carbon dioxide consists of autotrophic root respiration plus heterotrophic decomposition of organic matter and has been used in ecosystems approaching equilibrium as a measure of C inputs. The sites on this precipitation gradient cover a broad climatic range of unmanipulated, mature forests, meeting the general assumptions of this method. Therefore we assume that carbon released from the soil from heterotrophic respiration is approximately equivalent to the annual input of carbon entering the soil and, in combination with litterfall measurements, can be used as an index for below-ground NPP.
To measure carbon dioxide flux, static chambers were placed over tins containing soda lime for a 24 hour period, following established methods. Initially, ten randomly placed rings per site were pressed 1 cm into the surface of the soil and remained in the field during the course of this study so that fine roots would not be disturbed during measurements. During the 24 hour measurement periods, rings were removed and replaced with chambers of the same diameter such that a seal formed between the chamber and the soil. Tins of soda lime were dried at 105 degrees C and weighed before and after the field measurements, and blanks were used to correct for the drying process. The grams of CO2 adsorbed was calculated using a revised correction factor of 1.69 to account for weight differences between H2O and CO2. Soda lime has been shown in laboratory studies to overestimate very low (zero) fluxes and underestimate high fluxes but it is linear within a range of moderate fluxes where most of our measurements occurred. Furthermore, field studies have shown that it can be reliable compared to more sophisticated techniques over the range of carbon dioxide fluxes from soil, given the natural variability of soil fluxes.
This data set is available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).
Web Site: http://daac.ornl.gov
E-mail: uso@daac.ornl.gov
Telephone: +1 (865) 241-3952
Clark, D. A., S. Brown, D. W. Kicklighter, J. Q. Chambers, J. R. Thomlinson, J. Ni, and E. A. Holland. 2001a. Net primary production in tropical forests: an evaluation and synthesis of existing field data. Ecological Applications, 11(2): 371-384.
Clark, D.A., S. Brown, D.W. Kicklighter, J.Q. Chambers, J.R. Thomlinson, J. Ni, and E.A. Holland. 2001b. NPP Tropical Forest: Consistent Worldwide Site Estimates, 1967-1999. Data set. Available on-line [http://daac.ornl.gov] from the Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/616
Miller A. J., E. A. G. Schuur, and O. A. Chadwick. 2001. Redox control of phosphorus pools in montane forest soils in Hawaii. Geoderma 102:219-237.
Olson, R.J., K.R. Johnson, D.L. Zheng, and J.M.O. Scurlock. 2001. Global and Regional Ecosystem Modeling: Databases of Model Drivers and Validation Measurements. ORNL Technical Memorandum TM-2001/196. Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A.
Raich, J.W., A.E. Russell, and P.M. Vitousek. 1997. Primary productivity and ecosystem development along an elevational gradient on Mauna Loa, Hawai’i. Ecology 78: 707-721.
Schuur, E. A. G. 2003. Productivity and global climate revisited: the sensitivity of tropical forest growth to precipitation. Ecology 84 (5): 1165-1170.
Schuur, E. A. G., O. A. Chadwick, and P. A. Matson. 2001. Carbon cycling and soil carbon storage in mesic to wet Hawaiian montane forests. Ecology 82(11): 3182-3196.
Schuur, E. A. G. 2001. The effect of water on decomposition dynamics in mesic to wet Hawaiian montane forests. Ecosystems 4(3): 259-273.