HEM and LPH Towers - Litterfall

Data

• hf151-01: Hemlock litterfall
• hf151-02: Little Prospect Hill litterfall

Overview

• Lead: Julian Hadley
• Investigators:
• Contact: Julian Hadley
• Start date: 2002-11-01
• End date: ongoing
• Location: Prospect Hill Tract (Harvard Forest)
• Latitude: +42.539 to +42.542
• Longitude: -72.185 to -72.180
• Elevation: 355 to 380 meters
• Taxa:
• Research topic: plot
• Study type: long-term measurement
• LTER core area: primary production
• Keywords: carbon cycling, leaf litter, net primary productivity
• Release date: 2009
• EML version: knb-lter-hfr.151.3
• Revisions:
• Related links:
• EMS - Biomass Inventories
• HEM and LPH Towers - Tree Growth and Above-Ground Biomass
• Abstract:

  We measure the dry mass and estimated carbon content of leaves and fine twigs that abscise each year. These data are used to quantify one component of annual net primary productivity (ANPP), an important measure of ecosystem productivity and carbon cycling. Leaf area index (LAI) can also be estimated from these data, if area-to-mass ratios are calculated for leaves of each species. This was done for 2002 and 2003 leaf litterfall at the Little Prospect Hill (LPH) site. The fraction of total leaf mass or estimated total leaf area that is formed by leaves of each species also shows the species composition of the forest canopy. If repeated over many years, these data can indicate whether the forest canopy species composition is changing over time.

• Methods:

  Laundry baskets varying from about 40 to 45 cm across were placed in within circular plots in the footprints of the Little Prospect Hill and Hemlock eddy flux towers, in October 2002 for the Little Prospect Hill flux tower site and in October 2004 for the Harvard Forest Hemlock flux tower site. Baskets were placed in 36 plots at the Little Prospect Hill site and 12 plots at the Hemlock site. For a description of the number and locations of these circular plots, please see HF149. The baskets remain in the forest throughout the year and all leaves and fallen twigs are collected each year in November, after completion of the major period of leaf abscission for both deciduous and hemlock-dominated forests, in October for deciduous forest and September for the hemlock forest. The leaf litter is sorted by species, dried at 70 degrees Celsius for two days or longer, and weighed. Twigs, acorns, seed cones, and pieces of litter too small to be identified by species are also separated, dried at 70 degrees Celsius and weighed.

  The total dry masses of leaves and other fallen litter are divided by the cross-sectional area of the mouth of each litter basket to obtain values of mass per unit area. For 2002 and 2003 measurements at Little Prospect Hill, the estimated area of leaves of each species in each litter basket were also divided by the cross-sectional area of the mouth of each litter basket to obtain leaf area per unit ground area, which is leaf area index (LAI).

• Use:

  This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

• Citation:

  Hadley J. 2009. HEM and LPH Towers - Litterfall. Harvard Forest Data Archive: HF151.

Detailed Metadata

hf151-01: Hemlock litterfall

1. YEAR: year (YYYY)
2. DIST: distance from tower (meter )
3. TRANS: compass direction from Hemlock tower from geographic north (degree )
4. SPECIES: species (4-letter abbreviation) or other ID
5. SAMPLE_WT: weight of sample (gram )
6. TOT_WT: total weight (gram )
7. BASK_AREA: area of opening of litter basket (squareCentimeters )

hf151-02: Little Prospect Hill litterfall

1. YEAR: year (YYYY)
2. DIST: distance from tower (meter )
3. TRANS: compass direction from LPH tower from geographic north (degree )
4. SPECIES: species (4-letter abbreviation) or other ID
5. SUBSAMP_WT: weight of subsample (gram )
6. TOT_WT: total weight (gram )
7. SAMPLE_LA: sample leaf area (squareCentimeters )
8. BASK_AREA: area of opening of litter basket (squareCentimeters )