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Plant community or "phytocoenosis" (American spelling "phytocenosis", rarely used) is a collection of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighbouring patches of different vegetation types. The components of each plant community are influenced by soil type, topography, climate and human disturbance. In many cases there are several soil types within a given phytocoenosis.
A forest community includes the overstory, or upper tree layer of the canopy, as well as the understory, further subdivided into the shrub layer, herb layer, and sometimes also moss layer. In some cases of complex forests there is also a well-defined lower tree layer.
An example is a grassland on the northern CaucasusSteppes, where common grass species found are Festuca sulcataandPoa bulbosa. A common sedge in this grassland phytocoenosis isCarex shreberi. Other representativeforbs occurring in these steppe grasslands are Artemisia austriacaandPolygonum aviculare.
An example of a three tiered plant community is in Central Westland of South Island, New Zealand. These forests are the most extensive continuous reaches of podocarp/broadleaf forests in that country. The overstory includes miro, rimu and mountain totara. The mid-story includes tree ferns such as Cyathea smithiiandDicksonia squarrosa, whilst the lowest tier andepiphytic associates include Asplenium polyodon,Tmesipteris tannensis,Astelia solandriandBlechnum discolor.
A herbaceous plant (in botanical use simply herb) is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground. Herbaceous plants may be annuals, biennials or perennials.
Annual herbaceous plants die completely at the end of the growing season or when they have flowered and fruited, and they then grow again from seed.
Herbaceous perennial and biennial plants have stems that die at the end of the growing season, but parts of the plant survive under or close to the ground from season to season (for biennials, until the next growing season, when they flower and die). New growth develops from living tissues remaining on or under the ground, including roots, a caudex (a thickened portion of the stem at ground level) or various types of underground stems, such as bulbs, corms, stolons, rhizomes and tubers. Examples of herbaceous biennials include carrot, parsnip and common ragwort; herbaceous perennials include peony, hosta, mint, most ferns and most grasses. By contrast, non-herbaceous perennial plants are woody plants which have stems above ground that remain alive during the dormant season and grow shoots the next year from the above-ground parts – these include trees, shrubs and vines.
Some relatively fast-growing herbaceous plants (especially annuals) are pioneers, or early-successional species. Others form the main vegetation of many stable habitats, occurring for example in the ground layer of forests, or in naturally open habitats such as meadow, salt marsh or desert.
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Answers:The first one is true.No. 2 is true.No. 3 is true.I don't know for sure but i think no.4 is C .I know it is not A or B and D looks like a silly answer..No. 5 is D.
Answers:Most herbs prefer sun, but several thrive in shade. Home-gardening expert Tammy Algood offers some suggestions on herbs that can make do on 4 or fewer hours of sun each day. In gardening parlance the word shade rarely appears alone. It's usually paired with other words that indicate the degree of shade. In your garden, for example, there may be light shade, filtered shade, full shade or partial shade. Lemon balm (Melissa officinalis), a perennial herb hardy to Zone 3, grows well in poor soil as long as the drainage is good. It self-sows easily. Lemon balm may be used in teas, salads, and fish dishes or with fruit. Its dried leaves may be used in potpourris and sachets. Plants grow leggy and thin unless they're cut back several times a year. All herbs grown in shade will grow tall in an attempt to reach for the sun. Pinch the foliage back to keep plants compact and encourage new growth. Always use new leaves for cooking. Older foliage has a bitter flavor and a tough texture. Chives require frequent cutting to encourage production of new leaves. Chives may be used in soups and salads, as a garnish and as a seasoning for poultry, fish and pork. Parsley, a biennial herb, requires part shade in hot climates and may be grown in containers or window boxes. Italian flat-leaf parsley has an especially strong flavor. Soak parsley seeds for 24 hours before planting. Sweet woodruff (Galium odoratum) (figure A), a perennial, bears star-shaped white flowers in spring and requires partial shade in hot climates. It prefers a rich soil and can become a pest if unchecked. Foliage is hay-scented when dried and is used in making May wine. Rosemary (Rosmarinus officinalis) (figure B), an evergreen shrub, prefers full sun but may be grown in part shade. It is very aromatic when brushed or bruised and is used in cooking fish, poultry and game. Rosemary comes in upright and prostrate forms. The latter may be grown on a wall or in a hanging basket.
Answers:This is a classic succession question. Starting from, basically, a plowed field with probably little vegetation but residues of the crops, you are going to end up with the climax community for the area. It's a slow process, and each stage or "sere" in the process will eventually produce conditions unfavorable to itself, but favorable to the next level. In general, the biomass of plants on the field is going to increase with time, but the species diversity might actually decrease. Early succession forms will be weedy plants, quick to disperse and with short life cycles. Intermediate forms will be more sedentary, longer life cycles, and probably of mid height, until the climax community of probably trees (that's the assumption as trees are given) is reached. Think what is happening to the amount of sunlight hitting the soil at each stage and why a forest of trees, with a thick canopy, is going to restrict weedy plants from forming. There are internet sites that will explain the details... do a google search on abandoned field succession.
Answers:Mangrove trees or shrubs live in saline costal habitate yherefore these plant must adapt to such extremly saline environement to overcome the problems of anoxia, high salinity and frequent tidal inundation. ROOTS:are prop roots also known as Pneumatophore or Areil roots (prop themselves above the water level and can then absorb air through pores in their bark), these roots are always adventious roots, it contains wide aerenchyma to facilitate oxygen transport within the plant. roots are highly subrised that acting as an ultra-filtration mechanism to exclude sodium salts from the rest of the plant. Analysis of water inside mangroves has shown that 90% to 97% of salt has been excluded at the roots. Salt which does accumulate in the shoot concentrates in old leaves which the plant then sheds. STEM: stems are adapted to minimize the damage from waterborne objects like in Avicennia with its non-annual and non-concentric ring structure of alternating bands of xylem and phloem. LEAVES:mangrove trees can restrict the opening of their stomata on its leaf surfaces so they can limit the amount of water lost.They also vary the orientation of their leaves to avoid the harsh midday sun and so reduce evaporation from the leaves.Mangroves can also store salt in cell vacuoles or it can secrete salts directly; they have two salt glands at each leaf base SEEDS: are viviparous whose seeds germinate while still attached to the parent tree. Once germinated, the seedling grows either within the fruit or out through the fruit to form a propagule which can produce its own food via photosynthesis.