LTERN Data Portal

The 20 CSIRO permanent plots were opportunistically located ahead of logging operations or in areas of no or minor recent disturbance (EP9 and EP38 showed evidence of slight disturbance in a section of the plot due to selective logging at least 20 years prior to establishment). Where possible, plots were located to represent the major forests and geologies of North Queensland. All plots were surveyed to enclose a projected plan view area of 0.5 ha (100 m x 50 m) with plot boundary distances corrected for slope. Plot boundaries were surveyed with prismatic compasses, 50 m steel survey band and Abney level. The four plot corners were initially marked with treated wooden pegs and subsequently replaced with steel pickets. All plots were subdivided into 16 subplots, each 25 m x 12.5 m with permanent wooden subplot markers. A 20 m buffer area around each plot was established to exclude future human disturbance. A canopy tower was located adjacent to both EP4 and EP33 from establishment until 2005 and focussed on canopy sampling and photosynthetic studies. Data from the towers is not included in this data paper, however, publications resulting from data collected are included in the publications and results section. The plots were established between 1971 and 1980 and were initially censused every two years until 1991. Since 1991 census intervals have ranged between 2-15 years.

At each census, the diameter of all stems ≥10 cm DBH were measured with a diameter tape (Richter 2 m, Yamayo Million 10 m) to the nearest millimetre. Measurements made by the Commonwealth Forest and Timber Bureau at plot establishment followed protocols of Queensland Department of Forestry which are similar to the Smithsonian Institute methodology with two major exceptions, 1) for species known to exhibit buttressing on larger specimens, the point of measurement (POM) was pre-emptively elevated above the predicted buttressing influence. Prior to 1992 this was not always done as the buttressing nature of all species was not known. Subsequently, some point of measurement marks have been raised as buttresses moved their way up stems. In addition, some POM marks were lowered or raised due to deformations on the stem. In these cases only the newly raised or lowered DBH measurement was measured and DBH changed was recorded. 2) point of measurement lines approximately 25 mm wide and perpendicular to the trunk, and an alphanumeric stem code were painted on the stem. Rules of measurement are as follows:

1) Comments were recorded for unusual measurements that may affect the way the data is interpreted: 1 = raised or lowered point of measurement, 2 = broken top above POM, 3 = hollow stem, 4 = dead or damaged part of the stem, 5 = DBH estimated, 7 = sick stem, 8 = near dead stem, 9 = leaning >45°.

2) Stem diameters were measured in centimetres at breast height from the ground on the uphill side of the stem. Stems with DBH <10 cm were not included.

3) Stems leaning >45 degrees (comment 9) were measured 1.3 m along the stem along the underside of the stem.

4) Vines were pulled away from the stem or the diameter tape was slipped under the vines before measuring where possible. Where there was a reason why no measurement could be made, a visual estimation of the DBH was made (comment 5). This occurred when a stem had immovable vines, a strangler fig, or large and high buttresses.

5) Stems with a swelling or deformity that precludes taking a normal DBH measurement were measured above or below the deformity. If the deformity continued to <1 m above the ground then the measurement was taken above the deformity.

6) Stems with buttresses were measured at least 1 m above the highest buttress. Smaller specimens of particular species that were known to exhibit buttressing when they grow larger were measured at a higher POM to account for future buttressing. In this case the POM was decided on by the team leader.

7) Where the trunk was irregular, damaged, deformed or fluted at all heights, the POM was taken at 1.3 m. A comment of 3 or 4 was recorded for hollow or damaged stem.

8) Stems that forked above 1.3 m were measured below the fork where the stem was not swollen or deformed. Stems that forked below 1.3 m were measured as separate stems, at or close to 1.3 m.

9) Palms were included if the stem was ≥10 cm DBH below the lowest living leaf base.

10) Lianas were measured 1.3 m along the stem after they left the ground. The height of a liana was recorded as the estimated length of the stem and was generally higher than the host stem. Lianas were mapped where they were considered to originate.

11) The diameter of each individual stem (aerial root) of a strangler fig ≥10 cm DBH was measured separately. Over time when these roots merged with each other or the host stem, then the DBH was estimated (comment 5).

Lianas ≥10 cm DBH were not included in the census at establishment, were included selectively from 1987 onwards. Consequently, the 11 stems listed in Table 4 were most likely present as stems ≥10 cm before they were recorded in the database. All other lianas in the database (8 stems) were included in the database as they were recruited into the ≥10 cm DBH size class.

The positions of all stems ≥10 cm DBH were mapped to an accuracy of ±0.5 m. The X coordinate was taken as the projected plan distance in metres along the 100 m axis starting at the subplot A-D outside edge of the plot (Fig. 1). The Y coordinate was taken as the projected plan distance in metres along the 50 m axis starting at the subplot A-M outside edge. Where stems originated within 0.5 m of each other or in a multi-stemmed case, the same coordinates were shared within the same plot.

At establishment, the height of each stem ≥10 cm DBH was estimated. Height estimations were taken as the length of the stem from ground to upmost growing tip. Estimations were regularly validated for highly visible stems using the triangulation method (base distance and slope angle) with a clinometer and measuring tape. Height estimations were repeated in 1998 (2001 at EP37; not repeated at EP31) using the same method with the addition of a laser rangefinder (Newcon Optic 1200, Nikon Forestry 550) to aid in base distance, slope angle and direct height estimations where appropriate. Stems recruited at each census were given a height using the same method.

Stems were numbered using an alphanumeric code representing subplot (A to P) and sequential number within that subplot. This code was painted on the stem either below or above the POM line. Multi-stemmed individuals branching below the POM were numbered by placing a numeral in the ‘hundreds’ before the stem number. For example: in the same subplot, P005, P105 and P205 are separate trunks of the same individual branching at or below 1.3 m.

At each census following establishment, new stems recruiting into the ≥10 cm DBH size class were measured, mapped and assigned a height. All stems ≥10 cm DBH that had died since the last census were noted and no attempt was made to assign a cause of death. Stems that were dead or snapped below the painted POM line were considered dead. The nature and extent of major disturbances (e.g. cyclones, erosion) in each plot were noted and mapped.