K. Hulsman

ABSTRACT In this paper, we focus on how to use reduction to understand natural phenomena better. Natural phenomena occur in physical and living systems. Hierarchical physical systems are best represented as Complex Systems (CS), and living ones as Complex Adaptive Systems (CAS). CS and CAS differ in one important way. CAS can adapt by learning or evolving, whereas CS cannot. Any CAS is governed by a mix of level-invariant and level-specific rules, whereas CS has only level-invariant ones. Level-specific rules give rise to adaptive behaviour and affect the utility of reduction. There are three basic types of reduction: ontological, epistemic and methodological. Although biology cannot be reduced to physics and chemistry, all three reductive types have an important role to play in studying biological systems. Ontological reduction can help identify structural components at each level of a system, but not necessarily their functional relationships. This limitation arises when level-specific-rules and the information they generate are lost in the reductive process. Epistemic reduction meets the same limitation. The problem with methodological reduction is not knowing beforehand how many mechanisms produce the same outcome. To avoid this limitation, one must remain cognisant of level-specific rules and the information they supply. CAS should be studied by combining reduction and integration. First, use ontological reduction to identify the structural components at each level, second, use epistemic and/or methodological reduction, and third, use integration iteratively to reveal how components interact. This iterative top-down and bottom-up approach keeps the phenomenon in the context in which it occurs.

... One of the sites was a large area of eucalypt forest (Toohey Forest, approximately 650ha) surrounded by Brisbane suburbia on all ... Acknowledgments We thank Yasmin MacErlain, Phil Battley, Peta Blackford, Larry Cooper, Peter O' Reilly, Jr., Col Harmon, Roger Kitching, Pam ...

... BRIDLED TERN Gulls probably do not take any eggs or chicks of the Bridled Tern because it nests under the Wedelia biflora that covers the island. ... During the 1975-76 season, the Bridled Tern had a low breeding success (Table VI) . ...

HULSMAN, K. and LANGHAM, NPE Breeding biology of the Bridled Tern Sterna anaethetus. Emu 85: 240-249. Features of breeding Bridled Terns can be considered as either anti-predator or other adaptations. Each anti-predator feature acting by itself or with others can ...

... We thank Col Harmon, Michael Arthur, Peta Blackford, Yasmin McErlain, Meredith Romig, Roger Kitching, Peter O'Reilley Jr, Larry Cooper, Alaisdair ... Office of the Chief Plant Protection Officer, Commonwealth Department of Primary Industries and Griffith University, Brisbane. ...

... Sometimes a Bridled Tern while circling its nesting area regurgitated a fish; if the Tern was attacked by a Gull it swallowed the fish and the chase ended. Only once, when a Gull surprised a Bridled Tern carrying a balistid (4-6 cm) did a Tern lose its fish. TOTAL 6-8 8-10 TOTAL ...

Traditional methods of managing salt marsh mosquitoes focus primarily on maximizing the reduction of mosquito populations, with minimizing environmental impact as a secondary consideration. An environment-oriented approach to salt marsh management for mosquito control, runnelling, is described and compared with other forms of habitat modification such as ditching and Open Marsh Water Management (OMWM). Runnelling alters the salt marsh as little as possible while causing significant reductions in mosquito numbers. The effect of runnelling on the environment was monitored via the following variables: water table level, substrate characteristics (moisture, salinity and pH), vegetation (height and density of each Sporobolus virginicus) and the numbers of mosquito larvae. Runnelling had a statistically significant effect on only two of the seven variables. These were the height of Sporobolus, which increased near runnels, and the number of mosquito larvae, which decreased. The main diffe...

Large-scale colour infrared aerial photographs were obtained for part of a tropical coastal salt-marsh in south-east Queensland, Australia. Print reflectances were classified using a numerical divisive hierarchical procedure and related to field data. Vegetation characteristics such as species, size, dry weight and density were significantly associated with each spectral class al the general (macro) and at the detailed (micro) scales.

ABSTRACT Vegetation types on Masthead Island. Great Barrier Reef were analysed and related to the distribution and abundance of nests of black noddies, Anous minutus. Vegetation attributes used in the analysis were tree species in height classes for each replicated sample. A classification program based on information statistics was used to group the vegetation into four main types. These were the coastal Casuarina forest, low Pisonia forest. medium Pisonia forests and the tall Pisonia forest. The Casuarina forest was characterized by Casuarina trees in all height classes and by the paucity of other tree species. The Pisonia forests were dominated by Pisonia trees and were differentiated by the height of these and by the associated species and their heights. We suggest that the variety of species and heights associated with each type is related to stages in a succession process. The uneven distribution in time and space of disturbance is reflected in the patchy distribution of each of the Pisonia forests. Disturbances are probably initiated by wind damage to the vegetation.Noddies prefer to nest in specific vegetation types. Highest nest densities occurred in the medium Pisonia forests, especially where Pisonia trees were only > 6–8 m tall and were associated with Ficus, Celtis and Pipturus. Taller Pisonia forests in which Ficus and Celtis occurred also had fairly high nest densities. Since these Pisonia forests appear to be regenerating following damage, we suggest that noddy nesting is also related to disturbance. The paucity of nests in the low Pisonia forest implies that noddies avoid areas of recent disturbance, probably because suitable nest sites are scarce.