Temperate Deciduous pt 1 Flashcards
Temp decidous forest
- Moderate climate and dominance of hardwood decidous trees
- 4 distinct seaosns
- Sprintime sun passes through seasonally leafless trees to reach a diverse understory flora
- Soils are rich in nutrients from annual leaf fall
- The moderate temp and precipitation promote decomp
- Animal and fungi will chew on the fallen material inlcuding berries and helps the soil become more vibratnt
- Broadleaf forests are found throughout central and southern ontario
- Typucally warm summers and cold snowy winters - not extreme
- Moderate precipitation evenly throughout the year - this makes it much more moist compared to boreal forest
- Have a higher biodiversity than boreal forests
- Producers - primarly plants with trees being a focus
- Consumers - birds and small mamals are numerous; larger mamals (grazers and carnivores/scanevegers) are prominent
- Decomposers - fungus and invertebrates like insects, worms, gstprduct, crusteceans etc.
The fallen plant material/fruits/litter contribute to the vibrant soil community and helps the diet of consumers - this isnt rlly seen in the boreal forest
St lawrence forest zone
- The trees are mixed aged and diverse numbers of species are present - mdoerate species richness - 3-4 species per km sq:
○ Decidious trees (drop leaves in winter) various mapesl, oaks, beech, elm etc.- Our region of ontario is the great lakes - st lawrence forest zone
- Mixing area between decidous and boreal and more varied treees present
○ Confierous trees (retain levaes in winter) - red and white pine, hemlock and white cedar
○ Through colonization many trees were cultivated, namely our pine forests for logging - We can ID plants and trees by looking at their leaves
○ First look at branching is it opposie or alternative for leaves
○ Then look at shape of leaves - are tehre sharp edges etc.
○ Red pine have bundles of two while white pine has bundles of 5 - We have rich species of trees in the broadleaf mixed forest
Looking at the forest as a whole its fairly even - can find each type of tree relatively near eachother rather than miles away
Plants - land plants
- Approx 470 million years ago a group of green algae began the transition from water to land
- These first plants were small and resembled thei algal ancestors
- They had no way of obtaining water from the soil and had a limited capacity to restrict water loss
- Desicccation was a costant challenge for land palnts
Land plants finnally had the abilioty to protect themselves from drying out
Phylogeny of land plants
- Land plants form a specific monophyletic group descended from green algae
- Land plants divided into two gorups
○ Bryophytes - cannot uptake water this way and tehrefore are smal and stay in moist areas
Vascular plants - have vessels that can takeup water from soil and shoot it up
- Land plants divided into two gorups
Tracheophyta - vascular plants
- Vascular plants or plants with plumbing
- Snyapamorphy
○ Vascular tissue - xylem and phloem - Icnldue all living trees, herbaocus plants, all flower and fruit bearing plants
- Same basic life cycle among all vasuclar plants despite diversity
- Divided into four groups for converince:
○ Lycophyte
○ Ferns
○ Gymnosperms (coniferous)
Angisperms (maple, oaks, flowers etc.)
- Snyapamorphy
Plant Vascular System
- Vascular plant stems have a number of basic tissue types
- Vascular tissues lie in a ring near the outside of the stem
- Extends from tips of roots through the stem and into viens within leaves
- Xylem and phloem
- One will move water and other nutreints while the other moves photosynthase (glucose)
- The cambium of the stem/system will allow the tissue to become thick
Phloem anatomy
○ Carries photosynthates downard from leaf to roots
○ Phloem sap is the sugar-rich solution
○ Phloem transports carbs, aa, inroganic forms of nitrgen, ions, hormones, protein signals and RNA
During development, sieve elements lose lot of their intracellular structure including the nucleus and vacuole (transport of carbs happen in phloem which consists of multicellular sieve tubes composed of modified cells called sieve elements)
Xylem
○ Carry water and minerals upwards from the roots to the leaves
○ Xylem cells become very elongated during development
○ Lignin secreted by these cells provide strutral support
○ The nucelus and cytoplasm are lost leaving a hllow conduit where water can flow
Lignin produced can also help form trees if produced in large amount - allow green growth to become woody and strcutrual as a plant grows and needs to hold itself up
Main types of plants
- Trees and shrubs are plants that produce woody stems where greater amounts of lignin are present to provide strcutrual support through secondary growth
- These are primarly the angipserms and gymnosperms
- Some ferns forms trees but they are diff
The three types of overall plants would be a tree, shrub and then a herbcious plant (not enough lignin - found at undertsoyr of trees)
A herb is a non-woody plant that has an inexperienced and smooth stem with few branches on it. Shrub plants are taller than herbs and have stems branching out at their base. A tree is a woody plant that has many branches on a stem.
Basic Stem Anatomy
- Plant growth upwards is primary growth
- An increase in plants diaemetr is secodnary rgowth and occurs at the stem and roots
- This prcoess creates additional vascular tissue (more moevemnt of materails) and lignified vessels (strcutrual support for the plant)
- Vascular cambium differentiates to forms new xylem and phloem and produces wood
- The sexondayr xylem is towards the centre while phloem is outsdie
- Wood includes the primary and seocndary xylem; growth rings form if there is cyclic seasonal differences in the sizes, numbers and kinds of secondary xylem cells produced by cambium (ex. Spring wood has bigger cells)
- If a stem has a cambium as one of its primary tissue then it can add additional cells to inc the stem thickness this is a 2 degree growth
Wood in wild
wood is the reason trees can get tall and form forests that provide habitats for countless number of other organisms
Along with phsyical space, these plants produce seeds and fruits that contribute to consumers
Gymno and angio
- Gymnosperms and angiosperms are both seed plants
- Both produce seeds, function in dispersal
- Gymnosperms have male and female cones containing pollen or ovules; seeds dvelop as part of the cone
Angiosperms produce flowers that hold the pollen and ovule; fruit develops around seed
Plant life cycles
○ Plant lifecycles are fundemntally diff than tjose of aniamls
○ Plants proceed through mitosis in both their haploid and diploid phase
○ Diff major types of plants spend more time in one phase compared to the other
○ In the seed plant lifecycles - we mostly see a diploid stage - gametes are pollen (male) and ovule (female) - the zygote becomes the embryo, inside the seed, method of fertlization and dispersal will differ between the gymno and angio
Fertlization is when the pollen and ovule actually form the zygote - dispersal is just getting the male pollen or gameete to the ovule
life cycle of pine tree
1st yr pollen cone - microsporangium under the scales; where meiosis happens; sperm only enters in second spring
candle - ovulate cone 1st season
mature seed cone in the third season
key- timing is a bit different, but key characters the same
->adult sporophyte
microsporangium on pollen cone
meiosis then mitosis to make many pollen grains
pollen on ovulate cone
Pollen landing is first spring – fertlziation is second spring – delay because they don’t want to struggle in winter
fertilization takes a long time
female gametophyte dependent on sporophyte
Pollen dispersal of gymnosperms
○ Wind
○ Pollen from branches - pollen of gymnosperms is usually wind borne - itll meet with the female cones of ither trees
○ Wind must transport gymnosperm pollen to seed cone (whwre ovule is)
○ Seed cones are compoudn structures and take nearly two years to mature
Ovulate cones usually at top of these trees while pollen cones are spread all over or at tips
