glossary part 2 Flashcards
• Disturbance
A temporary and relatively discrete change in an ecosystem that causes pronounced changes in the ecology.
• Disturbance Regime
= The pattern of disturbances that shape ecology over a medium to long time-scale. Disturbance regimes are typically thought of as occurring on an ecological rather than evolutionary time-scale
• Anthropogenic =
(chiefly of environmental pollution and pollutants) originating in human activity
• Deciduous =
shedding its leaves annually
• Succession =
non-seasonal, directional and continuous patterns of vegetation change including colonisations and extinctions
• Primary forest
= native tree species, where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed
• Primary succession
= large-scale event → bare surface, no soil, e.g. glacial retreat, or new volcanic surface.
• Secondary succession =
= disturbance has not removed the substrate, e.g. fire, insect plague, land clearance. A biological legacy is left behind…
• Allogenic =
= seeds or plants arising from external sources eg. birds and animals
• Autogenic =
seeds and plants that self-generated from biological processes
• Secular succession
= Long-term changes in a landscape as a result of long term environmental change
• Forest physiognomy
o Ecological physiognomy encompasses the physical structures of an ecology
o Forest physiognomy is dominated by tree and understory structure
• Tree architecture:
o They physical features of a tree
o Not all trees are built the same
o Height and breadth of trunk, crown width, root depth, presence or absence of buttress, tap or stilt roots
• Buttress
o Very important for trees as strengthens and supports tree, Stops erosion
• Epiphyte
o A plant growing in another plant
o Often but not always parasitic as well as photosynthetic
• Hemiepiphyte:
o An epiphytic plant that starts in the crown of a tree or plant and grows roots down to the soil
o Example is a strangler fig
• Secondary Hemiepiphyte:
o An epiphytic plant that starts growing on the ground and then grows up the side of a tree into the leaves
o Often only uses the tree for structural support
• Canopy layer
o Continuous, largely unbroken layer of tree crowns
o Canopy layer tends to be continuous and dense
• Emergent layer:
o Occasional emergent species break above the canopy layer
• alpha richness
= number of species present
• beta richness/diversity
= rate at which species change between habitats
• gamma diversity =
= biogeographical diversity, total species diversity in a broad region
• Non-frequency dependent models
(model / hypothesis is independent of any relationship between species abundance and their growth, recruitment and mortality etc)
• Frequency dependent models =
model / hypothesis depends on / is interwoven with relationship between species abundance and their growth, recruitment and mortality etc)
• Monocrop =
is the agricultural practice of growing a single crop year after year on the same land, in the absence of rotation through other crops or growing multiple crops on the same land polyculture
• Deterministic:
- predict end points or equilibrium points
* driven by predictable and repeatable forces
• Non-deterministic
makes no predictions about end points of equilibria
• does not predict a ‘final’ species assemblage
• governed by stochastic effects
• Old growth forest =
that has attained great age without significant disturbance and thereby exhibits unique ecological features`
• Secondary forest =
forest or woodland area which has re-grown after a timber harvest, until a long enough period has passed so that the effects of the disturbance are no longer evident.
• carbon flux =
= rate of carbon passage through ecosystem
• Dichromatic =
able to see two colours
• Trichromatic =
= able to see three colours
• Secondary metabolism =
= are chemicals produced by plants for which no role has yet been found in growth, photosynthesis, reproduction, or other “primary” functions
• Ex situ =
= conservation is the preservation of components of biological diversity outside their natural habitats
• In situ =
= conservation is the preservation of components of biological diversity inside their natural habitats
• Crepuscular -
active at twilight (dawn and dusk)
• Old world monkeys: Asia and Africa:
o Wider range of sizes
o Narrow, forward pointing nostrils (Cattarhini – down-nosed)
o Cheek pouches in some, complex stomachs in others
o Included Old World Apes - Gorillas
o Eg. Siamang, Gibbon,
• New World Monkeys: South America
o Similar features among all NW monkeys suggest a single dispersal event (30 Mya)
o Small to medium-sized
o Wide nostrils, pointing to sides (Platyrhini—flat nosed)
o Some with prehensile tails
o No cheek pouches
• First phase of succession
Rapid colonisation by herbs, shrubs & climbers, 0-10 years
• Second phase of succession
- Short-lived by fast-growing shade-intolerant trees, 10-30 years
• Third phase of succession
- Understory re-initiation 75-100 years
• Fourth phase of succession
Development of old growth forest 100+ years
• Early successional species (pioneer)
o High allocation to roots - nutrient uptake
o Small seeds / lots of seeds – cheaper / dispersibility
o Shade intolerant - rapid growth in high light conditions
o Small (relative) size - short life span
o High photosynthetic rates - maximise growth
o Increased stomatal density - maximise gas exchange
o Thick sun leaves - protection from desiccation
• Late successional species
o Larger plants - long life spans o Fewer/ larger seeds • provides developing seedling with nutrition until it can photosynthesise o Slow relative growth rates • faster in light conditions o Shade tolerant
