biogeography Flashcards
biotic unit that are classified by predominant plant types
FACHBEGRIFF
BIOMES
examples biomes
forest - temperate, tropical and conifer temperate grasslands tropical savanna shrublands tundra desert
biome classification?
depends strongly on how fine…
terrestial biomes depend on?
connecting trends?
precipitation and mean annual temperature
but there is a trend…
the hotter the air, the more water it can hold
3 plant forms that contribute to terrestial ecosystem
advantages
trees and shrubs (woody) and grasses
trees get more height -> access to light (cost of maintnance and respiration)
grasses high proportion of photosynthetic tissue
forms of vegetation
FACHBEGRIFFe
DECIDUOUS:
winter-deciduous -> leaves are lost at low temps
summer-deciduous -> leaves are at dry condis
EVERGREEN:
broadleaf evergreen leaf -> environments with no season (tropics)
needle-leaf evergreen leaf -> where growing seasons are short (high latitudes)
going from high to low precipitation (terrestial)
- broadleaf evergreen (no season, tropics)
- drought-deciduous trees (seasonal tropical forests, distinct dry season)
- woodlands and savannas (dry)
- arid shrublands and desert
going from high to low temperature (terrestial)
- broadleaf evergreen
- winter deciduous trees (temperate forests)
- prairies, cannot support trees (low precip)
- needle-leaf evergreen (conifer forest or taiga)
- no support for trees -> tundra
- shorter growing and more extremes
climate diagram
location elevation mean temp mean precip mean monthly temp & precip
mean monthly precipitation
FACHBEGRIFF
~shows SEASONALITY
rain forest
broadleaf evergreen 10degN to 10degS mean temp > 18 min. monthly precip > 60mm largest in south america highest biodiversity 6% of land surface all primates in rainforest
dry tropical forests
tropical forest wiith dry season
the further from equator the longer the dryseason
largest in south america and africa
most is now farming
savannas
warm continental climate >18 C
large year to year differences in precip.
high seasonality (dry and wet season)-> many shrubs
leaves decompose only in wet season
rather high diversity
when more rain -> tends to woodland
when drier -> tends to grassland
temperate forest
dominate the wet regions in temperate zone
dominated by broadleaf deciduous trees (oak)
also temperate evergreen forests
many disappeared for croplands
conifer forests
FACHBEGRIFF
short summers harsh winters
low temperatures -> short growing season
permafrost -> saggy soils
frequent fires -> needed to free the seeds in ground
BOREAL FOREST (TAIGA) largest vegetation formation on earth (11%) of area
shrubland
small shrubs with multiple stems mediterranean ecosystems between 30deg and 40deg latitude frequent fires -> shurbs adapted drxy season!
natural grassland
moderate rainfall
not only climatic -> also due to agriculture and fire intervention
they need moderate temps and rainfall
arid regions and deserts
35% of landsurface
hardly no precipitation ~1 cm / year max
sahara largest, australia largest in southern hemisphere
cold ocean currents can cause deserts
some have shrubs (cool deserts and high elevation deserts
hot deserts have dwarf shrubs
ANALYSE CLIMATE DIAMGRAM!!!
LOOK ON SCALE!!!
tundra
also alpine tundras…
permantly frozen deep layer -> not much vegetation
overlaying active layer of OM thaws in summer and freezes in winter
low biodiv.
plants only active in 3 months, but then all day photosynthesis
major auqatic ecosystems
FACHBEGRIFFe
MARINE:
- open-water
- coastal
FRESHWATER:
- lotic -> flowing
- lentic -> non flowing
where salt and freshwater mix
FACHBEGRIFF
ESTUARY ~undirectional flow complex currents tidal oscillations many nutrients (except phosphorus) nutrients are trapped -> so high availability
Lakes and ponds
dimensions
origin
(FACHBEGRIFF)
LENTIC 1 to 2000m deep <1 ha to thoudans of km^2 ponds small and shallow -> ground is planted origin: glacial erosion sediment and debris damming cutoff rivers nongeological -> beaver dams ect.
zones in lakes and ponds
FACHBEGRIFF
horizontal:
littoral zone -> shallow water
limnetic zone -> openwater that extends to depth of light penetration
vertical:
littoral zone -> top water (light)
profundal zone -> no light penetration
benthic zone -> the ground -> place of decomposition
low high nutrient lake
FACHBEGRIFF
eutrophic:
high surface-volume ratio
nutrient rich from farmland ect
oligotrophic lake:
low surface-volume ratio
low nutrient input
easy fischig
flowing water ecosystems
order
FACHBEGRIFF
LOTIC
first steep and not much water and fast
then not steep and much water and slow
in the end much sediment disposits
first order stream - small headwater (quelle) streams
2nd order stream - when 2 first order join
3rd order stream - when 2 2nd order join
influence of flow
flow determines ecosystem:
oxygen availability
water temp
nutrient spiraling
velocity in stream
is lower close to banks and at the ground
marine ecosystem
divisions
70 % of earth
seas are interconnected by currents
benthic zone -> bottom region
pelagic zone -> whole body of water:
- neritic province: over continental shelf
- oceanic province: over abyssal zone
where primary production in ocean
where light and nutrients
shallow waters and upwelling zones
human activities on marine ecosystems
input of nitrogen and phosphor lead to anoxic zones ->DEAD ZONES
1. N & P input -> NPP of plankton increase -> they die sink down -> zoopl. consume them and grow in the deep-> respiration use up the oxygen in deep -> oxygen in top layer gets winded away -> low oxygen upwelling -> organisms die
largest dead zone
GOLF OF MEXICO huge eutrophication by mississippi river to restore: manage nutrient inputs restore wetlands riparian ecosystems to capture nutrients and reduce runoff
auzone ecosystem
FACHBEGRIFF
RIPARIAN
zone between stream and forest
cleans the groundwater ect. from nutrients
