Forest canopies include tree boles, limbs, and foliage as well as the sessile organisms upon and air spaces around these tree components. Most rope-based canopy access systems (SRT, arborist, traverse and transect) are "arborcentric" and may not provide easy access to the full canopy between tree boles and limbs. Most infrastructure access systems (cranes, rafts, towers, walkways) are expensive and often biased against sampling near ground or mid canopy. This presentation asks, how do infrastructure systems compare to rope-based ones? What are the advantages and disadvantages of each? Can rope-based systems be used to sample the full extent of the canopy profile? If so, how can it be done safely? What are some some of the advantages, challenges, and limitations of rope-based, full-canopy sampling? What equipment is needed and what can be sampled? To answer these questions an access and movement system developed over the last decade and applied to Sitka spruce, westen hemlock, and Douglas-fir forests in the USA; Eucalyptus regnans in Australia; Dipterocarp forests in Malaysia; and lowland tropical rain forest in Costa Rica is described. The system was used to collect data on forest canopy structure, microclimate, and arthropod abundance from 1 m above ground to over the canopy surface in both temperate and tropical forests > 70 m tall.
Results/Conclusions
Infrastructure systems can give more people access to the canopy surface but are limited in team size (canopy raft and its descendants), replication (cranes, towers), and portions of the canopy available to sampling. Rope-based systems such as SRT and arborist are usually limited to below the canopy surface, often require special skills, and are usually limited to near tree trunks. A full canopy, rope-based traverse and transect method for access and sampling methods is found to be possible and practical. The principle advantages include:
- amount of canopy volume available for sampling
- relative inexpense for the system (< US$10,000)
- safety
- availability of equipment
- transportability
- amount of data collectable
- relatively low technical mastery needed for collecting data
- potential for hybridization with infrastructure methods
