• Introduction
  

The Seine River

• Route Map
  
  
• Goal and Objective
  
  
• The Seine in Winter
  
  
• Natural Processes in Winter
  

• References and Appendix
  

Natural Processes in Winter

In the following description I briefly try to understand the natural processes of various species that are part of Seine River habitat. Through the process of natural selection, animals adopt three basic strategies to survive the winter; migration, hibernation, and resistance.

Wildlife
Beavers are an integral part of the Seine River ecosystem. The river is full of beaver activities during summer months. However, according to SOS, a small-scale beaver dams management is required during summer to maintain water level and protect other species. I observed evidence of beaver activity in the stretch between Marion St. and Railway Bridge. Beavers take shelter in their lodges. These lodges are connected to the river where they store their food. Deer, rabbits and some species of owls develop resistance, and thus endure and remain during the winter. The deer and rabbit change their diet during winter from green plants to bark and twigs. Rabbits adopt the method of 'Coprophagy' i.e. eat their own scat to get most energy out of the food. Deer tend to gather up in one area (The Big Freeze, 2003). I was not fortunate enough to come across any animal species during the winter walk. Nevertheless, there was evidence of deer and rabbit footprints at different locations.  The Seine has a relatively low stream discharge and an abundance of ice during winter. This potentially prevents stream habitat species to move to a more suitable habitat (i.e. Red River) and results in a higher mortality rate. During late winter periods, fish take shelter beneath rubble-boulders, woody debris, undercut banks and, shelf ice. They also tend to take shelter in 'winter-warm' microhabitats formed by point sources of groundwater discharge (Cunjak, 1995). Certain fishes undergo physiological adaptations to adapt to winter conditions. They produce chemicals within and between cell walls that lower their freezing temperature by a few degrees. Stream channel habitat was frozen. 

Winter survival of many organisms depends on the presence of insulating cover of snow (Marchand, 1991). 

A lower-density cover of snow has a higher insulative quality. Snow along the shoreline is quite soft, which becomes an ideal habitat for mice, shrews, moles and other rodents (see picture 8). So it is crucial for these species to have approximately 20 cm cover of snow to get protection from cold. The subnivean air space allows these animals to survive. They periodically make tiny holes to the surface to allow escape of carbon dioxide build-up. 

Plants
Plants undergo morphological and physiological changes to adapt to the severe cold of winter. There are four strategies that plants employ (Marchand, 1991). 

• Either leaf drop or adaptations for leaf retention
• A physiological acclimation process
• Resolution of water issues
• Methods of reducing mechanical damage 
  

Land-use
Land-use along the Seine is residential, recreational and light industrial in nature. However, paths, which run along the river, are pubic. Some of the buildings along the river appear to have been built very close to the riparian corridor (Marsh, 1997 pp 391). This might result in increased run-off during precipitation. Some waste and derelict vehicles were observed along the industrial belt at one location (see picture 10). The day was sunny and the temperature was relatively warm. At some points there were patches of water on the surface of the river. There are two main reasons for this, 1) patches receiving direct sunlight and 2) patches, which received storm water runoff from surrounding areas. 

Other interesting aspects
An event like the winter walk broadens the citizen base that appreciates the river. People tend to walk on the frozen river; as a result the residential property owners get used to their presence and eventually gain more acceptance. Whereas in summer, the property owners may feel intruded upon even if people walk on public stretch along the river. Thus, increased winter activities lead to positive relationships and area residents eventually learn to share their perceived backyards with visitors (Danyluk, 2004). A watchful eye also tends to discourage activities that are not in harmony with nature. 

Conclusion:
The 11 km winter walk in a rich ecological corridor helped me to understand interesting adaptations of animals and plants for coping with the harsh north winter. This is a very different experience from summer months. The stillness of winter landscape along the River Seine made me appreciate the cold season and the incredible ability of flora and fauna to adapt to and survive in such extreme conditions.