What is stratification?Ans: The plants occurring together with a similar ecology in definite strata are called stratification.
- What is periodicity?
Ans: The rhythmic phenomena related to seasonal changes is called periodicity. These changes are growth, flowering, pollination, ripening of fruit and seed. Periodicity is controlled by different-environmental factors like light, temperature etc.
- What are synthetic characteristics?
Ans: The generalization and integration of characteristics that derived from data of analytic qualities are called synthetic characteristics. In this case, data is arranged in tubular form. Then synthetic characteristics are studied.
- What are physiognomic characteristics?
Ans: The general appearance or outlines of the stand or community are called physiognomic characteristics.
- What are Phanerophytes? Give examples. These plants include woody trees and shrubs. Their bud bearing shoots are elevated and exposed to the atmosphere. Example, Acacia sp. What is transect? Give its uses.
Ans: A transect is a long rectangular sample plot. It is used to study
variations in vegetation. Vegetation varies with the changing environments. These ‘ariations are caused by slope, exposure, • edaphic and topographical irregularities.
- What is a quadrate? Give its uses.
Ans: A quadrat is a sampling unit used for the quantitative study of plant communities. It may be a square, rectangular or circular in shape. But rectangular plots are more useful. A quadrat can have any size. But generally, large quadrat is used for richer and heterogenous plant community.
- What is primary succession?
Ans: The formation of ecosystem from bare rock, sand or clear glacial pool where previous life does not exist is called primary succession. In this case, the ecosystem is formed from the start. So it is a long process.
-What Xerophytes and succulent plants?
Ans: Plants growing in xeric condition are called xerophytes. Xerophytes can withstand prolonged periods of water shortage. Water is stored in large parenchyma tissue in succulent plants like cacti.
- What is simple and mixed aggregation?
Ans: The grouping and growing of offspring around the parent plant is caged simple aggregation. The gradual spreading and mixing of the neighbouring plants is called mixed aggregation.
- What is Monoclimax theory?
Ans: According to this theory there is only one climax community in a climax geographical region; But topographic differences and different in types form other communities in the same zone.
These communities are known as subordinate communities.
- What is Polyclimax theory?
Ans: This theory was put forward by European ecologists Nicholos. Champion and Whitaxer in I 953. According to this theory a nuniber of different climax communities are present in climatic or geographical region. Thus preclimax, postclimax and disci imax communities are all climax communities.
- Differentiate between primary and secondary productivity.
Ans: The rate at which solar energy is converted into organic energy by green plants or total food assimilation rate of producers is called primary productivity. The amount of energy available to other trophic levels i.e. the heterotrophs or the consumers are called secondary Productivity.
- In which regions do the local vegetation divided in Pakistan?
Dry tropical forest vegetation
(i) Dry sub-tropical sub-mountainous vegetation
(ii) Dry Temperate forests vegetation
(iii)Moist temperature forest vegetation
(iv) Sub —Alpine and Alpine vegetation