Question

Select the correct statement regarding xerosere

• A. It is the ecological succession on bare rocks that are water deficient but rich in organic matter
• B. Crustose lichens such as Parmelia and Dermatocarpon are the pioneer community in xerosere
• C. Hypnum and Tortula constitute the annual grass stage of xerosere
• D. Zizyphus and Capparis constitute shrub stage of xerosere

Answer 1

The correct option is A It is the ecological succession on bare rocks that are water deficient but rich in organic matter

• Xerosere is a plant succession that is limited by water availability and availability of organic matter. They originate mostly on bare rocks.
• Crustose lichens are the pioneer species in xerosere. They can absorb and retain more water and withstand desiccation due to extreme dryness. The common species of crustose lichens are Rhizocarpon, Rinsodina etc. Parmelia and Dermatocarpon are species of foliose lichens that appear after the crustose lichens have converted the bare rocks and a little amount of soil has appeared.
  
• Tortula is a species in the moss stage of the xerosere.
• Zizyphus and Capparis are perennial woody plants of the shrub stage of xerosere.

So, the correct option is 'It is the ecological succession on bare rocks that are water deficient but rich in organic matter and Zizyphus and Capparis constitute shrub stage of xerosere'.