E2

only about _____-_____% of above ground production directly used by animals

10-30

microorganisms, algae, plants, small aquatic animals

nutrients released by detritus into water and soil are assimilated by _______, ______, _______ and ________

detritus

is a major substrate used by invertebrates

invertebrates

________ are a critical resource for many vertebrates

initial loss due to leaching period of microbial decomposition and conditioning mechanical and invertebrate fragmentation

3 phases of decomposition

leaching

dead vascular plant material begins to lose soluble organic and inorganic materials shortly after immersion in water, generally there is rapid loss over the 1st 24 hours followed by a gradual decline for an extended period, loosely bound nutrients such as Ca, K, and Mg are rapidly released

water temperatures, turbulence, leaf species

factors that affect leaching include:

higher

water temperature- high temperatures have _______ breakdown rates

increases

high turbulence _______ leaching

microbial colonization

______ is rapid after litter enters the water, generally peak in a few days and then begin to decline

microorganisms

_______ make the litter more palatable to macro invertebrates but possibly more importantly, they serve as food for the macro invertebrates

shredder

feed on vascular plant tissue (crustaceans)

collectors

feed on detrital particles (midge larvae-chironomids)

scrapers

feed on algae attached to plant tissue (pond and orb snails)

predators

feed on live vertebrate and or invertebrate prey (odonates; giant water bugs)

reenter the soil plant production

decomposition cycle is complete when the nutrients _______ and then begin to influence ________

release rate of nutrients, accumulation rate of litter, state or quality of flitter substrate

rate of decomposition is important because it affects the _______, _______, and ________

internal factors

chemical and physical characteristics of the leaves themselves
- lignin content
- nitrogen content
- presence of chemical inhibitors
- differences among plant parts

external factors

environmental factors
- temperature
- dissolved nutrient concentrations
- invertebrate densities/composition
- acidity
- type of wetland
- anthropogenic effects

prevents

continuous flooding ______ decomposition

increases

periodic flooding ______ decomposition relative to dry conditions

faster

non woody plants break down significantly ______ than woody plants

faster

in general submerged and floating macrophytes break down _______ than emergent macrophytes

fiber/lignin content, nutrient content, presence of chemical inhibitors

factors affecting species differences in decomposition

lignin content

negatively correlated with breakdown rates, is a supporting structure

low

floating and submerged aquatic plants have _______ lignin content; they are supported by the surface of the water and the water column respectively

higher

emergents generally have ______ lignin content because they must support themselves

type of wetland

probably reflects differences in the combination of external factors

anthropogenic disturbance

eutrophication, acid mine drainage, impoundment and channelization, etc

wetland invertebrates

important for nutrient cycling in wetlands, also a critical food resource for a variety of vertebrates including waterfowl, wading birds, shorebirds, amphibians, reptiles, and fish, particularly critical for waterfowl during the pre-breeding and breeding periods during molt

chrironomid

________ larvae are very important waterfowl food

wetland specialists

some species are generalists that occur in both aquatic and wetland habitats but in some families most species are _______ (water boatmen, back swimmers, predaceous diving beetles)

above and below waterline

wetlands often include several types of habitats including ________ habitats

seldom intermix

wetland inverts can mix with aquatic and terrestrial species but aquatic and terrestrial species ________

benthic, water column, periphytic, water surface

basic types of invertebrates

permanence, predictability of drying and filling, phenology of drying and filling, duration of dry and wet phases, harshness during both phases

the following wetland hydroperiod characteristics are important

mobility

fly away when wetland dries and return when refolded

drought resistant eggs

laid in dry basin and hatch when reflooded

snails

______ burrow into substate or secrete mucilaginous covering over the shell opening that forms a hardened seal

adaptations to low do

specialized gills or direct cuticular exchange, capture air directly from water surface, production of hemoglobin, mucus secretion of epidermis, anaerobic respiration

drawdown stage

dormant forms and flying adalts

regenerating stage

initial submersed habitat consists of annual and emergent litter with new emergent vegetation developing later in the spring, 1st species are those hatching from drought resistant eggs and mobile adults, flooded plant litter and algae rapidly become available with continued flooding annual mudflat plants replaced by robust emergents

degenerating stage

lake stage

wetland now consists of submergent vegetation, emergent vegetation along wetland edge and unvegetated substrate, benthic chironomids become dominant invertebrate

blackwater rivers

arise in coastal plain, have less developed floodplain soils are local, lower sediment loads, generally less fertile soils, hydrology is flashier

tannins

blackwater comes from

alluvial rivers

arise outside coastal plain, have higher sediment loads, higher macronutrient contents and longer hydroperiods, have better developed geomorphic features, much variation within them as they are largely dependent upon geology of their watershed, differences in soils affect vegetation

effect of gradient changes

nickpoint migrates upstream causing bed lowering upstream of nick point can reduce flow frequency and lower floodplain water table, can be natural or anthropogenic process

tectonics

_______ create relief that drives erosion, it generates earthquakes which provides lots of sediments to rivers and it causes avulsions and gradient changes

floodplains

formed from erosion and deposition of sediments

types and rates

_______ of erosion and deposition dictate species composition, surface and groundwater flooding patterns and vegetation

alluvial fans

________ and other landforms display similar variability within and among landforms

natural levee

coarse sediment deposition occurs here, often can be highest point on floodplain

oxbows

result from cutoff of meanders, important habitat for a variety of fish and wildlife, connectivity to river is important connectivity varies with river stage, some may fill with sediment others may be scoured, water clarity, depth, bank slope, sediment deposition/erosion patterns, hydroperiod, river connectivity, and age greatly influence vegetation and wildlife communities, surrounding land use is also important

ridge and swale

meander scrolls, depressions and ridges that occur on the convex bends of rivers, formed from point bars as stream migrates laterally cross floodplain

backswamps

occur between natural levee and valley wall, fine sediements tend to fall out in this area, beaver and a variety of herbs and birds occur here depending upon timing and duration of water

clay

backwamp = ____

overbook flooding, groundwater, precipitation

potential water sources for tree growth and survival

overbank flooding

flooding of floodplain can occur prior to overbank flooding due to connection with distributaries, can correlate flooding at a given point, and sometimes a given elevetation, with river stage by repeated water depth measurements at a given point, can calculate exceedance probabilities, timing and duration of flood events is critical in the life history of plants and animals

groundwater processes

in general moves down valley and toward channel, moves from high head pressure to low head pressure affected by soil types/layers and floodplain features, in general sites closer to river are more connected to river stage

sediment stratigraphy

groundwater levels far from river can be connected to stage depending on _______-

regional aquifers

shallow groundwater may also be connected to _______, over pumping of aquifer can lead to reduced river stage and or lower groundwater tables

hydrologic connectivity

ensures the water mediated transport of energy and organisms within or between elements of the hydrologic cycle

runoff, precipitation, groundwater

______, _______, and _______ are the primary hydrologic inputs into river/floodplain systems, relative importance varies among and within watersheds, years, and seasons and is dependent upon the degree of hydrologic connectivity among uplands, the river, its floodplain, and its estuaries

longitudinal, vertical, horizontal, temporal

four types of connectivity

longitudinal

upstream to downstream; estuaries

vertical

river to groundwater, including hyporheic zone

horizontal

connectivity to floodplain

temporal

variability in time among the other three forms of connectivity

flood pulse concept

maintenance of the lateral connectivity between the river and its floodplain is critical for productivity of forests, river, and associated organisms, not applicable to all systems

daily fluctuations with weather, seasonal patterns, multi year variations

variability at multiple time scales:

drought

variability in water budget is important _______ is critical to long term wetland function

clementsian succession

broad, correlative relationships among hydrology, geomorphology, and vegetation in blah has been disrupted and a mechanistic understanding is needed to understand change

lower greater

toner and keddy found that the longer the time of first flood the _____ the probability of woody vegetation; the later the time of the 2nd flood the ______ the probability of woody vegetation

herbaceous vegetation

greater than 40% of growing season flooded by 1st flood at their site led to dominance by ________

regeneration processes

timing of 2nd flood also likely related to __________

woody species

shade tolerance, flood tolerance, drought tolerance, competitive mechanisms linked to flooding patterns, sediment tolerance, spatial and temporal variability in hydrogeomorphic conditions within and among sites creates diverse responses

disturbance, dispersal/seedbank, seed germination, seedling establishment, competition

processes of gleasonian succession

recruitment

each stage of ______ is an independent process that may potentially limit regeneration, seeds/seedlings highly vulnerable, hydrology, geomorphology and light all strongly influence a species success in transitioning from one stage to the next

flooding

brings in nutrients and water to sustain growth

flood tolerance gradient

species generally structured along _______

stem densities

flooding likely reduced _______, which reduces competition and increases light

intolerant

in general BLH oaks tend to be shade ______

fecundity

highly variable from year to year within and among species, depends on tree age, health, vigor and environment

light seeded species

many small seeds

heavy seeded species

fewer large seeds

hydrochroy

seeds dispersed by water

drawdown

virtually all BLH species require a ______ for germination including baldcypress

type, depth

the ______ and ______ of sediment deposited can also influence germination rates

willow cottonwood

_____ requires bare mineral soil whereas ______ occurs more frequently on bare sandier soil

forest composition

shifts in amount and type of sediment can influence both germination rates and seedling establishment patterns, thus influencing future ________

germination

depends on windows of opportunities (microsite conditions, disturbance) species phenology many control timing, species respond uniquely to different flood effects

establishment

defined as the first three years of seedling survival, some species capable of resprouting following harvesting

flooding

primary filter on species composition; amount of shade also important

flood events

timing of germination relative to subsequent ______ affects probability of successful establishment

lower

early season germinates usually have ______ chance of survival

earlier later

generally lighter seeded species emerge ______ in the season and heavier seeded species emerge ______-

shade tolerant

sugary berry, American elm, and green ash are species that are ______ and tend to dominate forests in the MAV in the absence of canopy disturbance and reduced flooding

advance regeneration adequate light

for shade intolerant red oaks, ______ pre harvest and ________ to sustain regeneration post harvest is needed, this can be achieved through clearcuts, shelterwood, or group selection depending on size and frequency of reentry

rooting zone

tree growth is driven by soil moisture in the _______