1 



Major Findings 



John E. Hobbie 



INTRODUCTION 



Studies in the extreme environments of mountains, tropics, and the 

 Arctic have long been an important part of ecological research. Apart 

 from the stimulation and enjoyment of visiting new places, ecologists have 

 compared these extreme habitats with one another and with temperate 

 habitats in order to test hypotheses about general principles. This 

 approach of comparative natural history requires a large body of data 

 collected from many habitats; both descriptions and a good understanding 

 of processes are required. The data from extreme environments are 

 especially valuable as they extend the range of important variables and 

 may even allow analyses of the effect of certain factors that always vary 

 together in temperate regions. 



The IBP study of arctic ponds reported in this book is primarily a 

 description of the habitat, the biota, and the processes by which organisms 

 interact with other organisms and with their physical and chemical 

 environments. In the report, the comparative aspects of the study have 

 been deliberately de-emphasized, as constant reference to temperate and 

 tropical lakes would have quickly doubled the size of the book. The value 

 of the study in this comparative sense will become apparent later, when 

 this study is referred to to find out what controlled photosynthesis, how 

 rapidly a sedge leaf decomposed, or what the community structure was in 

 an arctic pond. 



In addition to the comparative importance of the arctic ponds, there 

 are certain advantages to investigating aquatic processes in the Arctic. For 

 example, low diversity of the higher plants and animals allows cohorts and 

 age classes to be identified and followed through time; this simplifies 

 productivity measurements. In some groups, such as most of the 

 zooplankton, there may be only a single generation each year which also 

 greatly simplifies growth measurements. The low diversity also permits a 

 more complete study to be carried out with fewer scientists but does not, of 

 course, make the study of an individual process any easier. 



There are other tactical advantages to arctic research. First, the 

 ponds freeze completely in mid-September, so they need to be studied for 

 only 3 months a year (which fits into academic schedules quite well). 

 During the field research months the scientists were working in crowded 

 laboratories in an isolated location where there were few distractions from 



1 



