Transcript Ponds & Lakes

By Sangon Kim
Maura Gerke
Location
 These regions range in size from just a few square
meters to thousands of square kilometers. Scattered
throughout the earth, several are remnants from the
Pleistocene glaciation. Many ponds are seasonal,
lasting just a couple of months (such as sessile pools)
while lakes may exist for hundreds of years or more.
 Natural lakes on Earth are generally found in
mountainous areas, rift zones, and areas with ongoing
or recent glaciation.
 Have numerous small invertebrate animals
(zooplanktons), both herbivores and carnivores.
 Finfish annd shellfish
 Their gills must be able to diffuse dissolved gasses
while keeping the salts in the body fluids inside. Their
scales reduce water diffusion through the skin:
freshwater fish that have lost too many scales will die.
They also have well developed kidneys to reclaim salts
from body fluids before excretion.
 Lack of rigid structures in freshwater plants. This is due to the density of the
water (much higher than that of an open air environment), which 'pushes'
against the plant in its daily life. This allows such plants to be more flexible
against oncoming water tides, and prevents damage to the plant.
As plants require a minimum concentration of gases in their diet such as
carbon dioxide, they require a degree of buoyancy so that contact can be made
with the open air environment. Adaptations may include;
Air Spaces - Air spaces in the plant will decrease density and increase buoyancy.
Broad Leaves - Broader leaves will spread their weight more evenly across the
water surface allowing them to float.
Waxy Cuticle - On the upper half to allow water to run off the surface to
prevent the weight of the water dragging the leaves under the surface.
 The sunlight supports the growth of rooted plants
from shore to shore. Some pond plants grow entirely
underwater or have parts that extend above the
surface. Leafy plants may float on the surface. Other
plants can grow along the pond edge. If left alone,
ponds will eventually fill in with dirt and debris until
they become solid land. It often takes hundreds of
years for a pond to be transformed from a body of clear
water into soil.
Three Other Features
 Eutrophication– an increase in the concentration of
nutrient content to an extent that increases the
primary productivity of the waterbody (increase in
phytoplankton).
 Divided into three zones according to depth and
distance from shoreline-1) littoral zone 2) limnetic
zone 3) profundal zone
 A recent tectonic uplift of a mountain range can create
bowl-shaped depressions that accumulate water and
form lakes.
Value to Humans
 Critical to our water supply for homes, industry,
recreation, and agriculture.
 Water reservoir
 Many lakes are artificial and are constructed for hydroelectric power generation, aesthetic purposes,
recreational purposes, industrial use, agricultural use
or domestic water supply.
 The amount of water that these reservoirs contain is
dropping significantly due to human activities.
 The pollutants from the air and un-processesed water
disturb the pH and increase the factors in killing
aquatic organisms.
 The global warming causes water temperature rise
each year which depletes oxygen molecules needed by
aquatic organisms to survive.
 The extensive use of fertilizers add excessive nutrients
such as phosphorous and nitrogen that cause the
eutrophication of the lake.
Animals
 Platypus
 Ornithorhynchus
anatinus
 Webbed, clawed feet
and leathery bill
 Caiman
 Caiman crocodilus
 Leathery skin
 Carp
 Cyprinus carpio
 Large scales
Species Diversity
 Limited because separated from other water sources
 Many species of plankton
 Most life in shallower waters
Plants
 Cattails
 Typha latifolia
 Large spongy brown spike
 Lotus flower
 Nelumbo nucifera
 Rapidly spreading pink or
white flowers
 Giant bulrush
 Schoenoplectus
californicus
 10ft tall sharp blades
Temperature Range
 Temperature varies in ponds and lakes seasonally. During
the summer, the temperature can range from 4° C near the
bottom to 22° C at the top. During the winter, the
temperature at the bottom can be 4° C while the top is 0° C
(ice). In between the two layers, there is a narrow zone
called the thermocline where the temperature of the water
changes rapidly. During the spring and fall seasons, there is
a mixing of the top and bottom layers, usually due to
winds, which results in a uniform water temperature of
around 4° C. This mixing also circulates oxygen throughout
the lake. Of course there are many lakes and ponds that do
not freeze during the winter, thus the top layer would be a
little warmer.
Precipitation
 Rain and snow replenish freshwater lakes and ponds
 Moisture in the air from evaporation creates clouds
and causes more precipitation
 Some precipitation seeps into the ground but other
becomes runoff into ponds and lakes
Works cited
 Johnson, Larry. Lamb Annette. “Pond Life” 2000.
42explore. 1 Sep. 2010 http://42explore.com/pond.htm
 “Pond” 2005 Island Creeks. 1 Sep. 2010.
http://www.fcps.edu/islandcreekes/ecology/pond.htm
 “LAKES AND PONDS.” Biomes of the World 2003.
Explore Biodiversity and Wild Classroom. 1 Sep. 2010.
http://www.thewildclassroom.com/biomes/lake.html
Works Cited
 Ponds and lakes. (2002). Retrieved from
http://www.mbgnet.net/fresh/lakes/index.htm
 Ponds and lakes: plants. (2010). Retrieved from
http://www.bcgrasslands.org/grasslands/pondsla
kes/plants.htm
 Sen, D. (2010, April 2). Freshwater biome abiotic
factors. Retrieved from
http://www.ehow.com/list_6190259_freshwaterbiome-abiotic-factors.html