Lesson 14

Question 1

Colonization of stone by plants and micro-organisms such as bacteria, Cyanobacteria, algae, fungi, and lichen (symbiosis of latter three).

Answer 1

Biological colonization

Question 2

Influences by other organisms such as animal nesting on and in stone. Direct growth on and in stone or stone cavities ; also indirect influences by nearby trees and other organisms

Answer 2

Biological coloniztaion

Question 3

Microscopic vegetal organisms without stem nor leaves which can be seen outdoors and indoors, as powdery or viscous deposits (thickness: tenth of mm to several mm)

Answer 3

Algae

Question 4

Form green, red, brown, or black veil like zones and can be found mainly in situations where the substrate remains moistened for long periods of time.. depending on environmental conditions and substrate type, may form solid layers or smooth films, on monuments, they are constituted of unicellular to pluricellular clusters, and they never form microorganisms

Answer 4

Algae

Question 5

Generally constitute superficial films. May be found also deeper into substrate (under scales, in cracks)

Answer 5

Algae

Question 6

Vegetal organism forming rounded millimetric to centimetric
crusty or bushy patches, often having a leathery appearance, growing
generally on outside parts of a building.

Answer 6

lichen

Question 7

composed of a thallus, eventually bearing fruiting bodies,
generally developed on the stone surface, and rhizines that may
penetrate deep into the stone (tens to several millimeters)

Answer 7

lichen

Question 8

are most commonly grey,
yellow, orange, green or black and show no differentiation into stem,
root and leaf. Algae generally constitute superficial films. They may be
found also deeper into the substrate (under scales, in cracks)

Answer 8

Lichen

Question 9

sub-types of lichen

Answer 9

re divided into crustose, folious and epilithic types

Question 10

When their thallus is mainly inside the stone, they are called

Answer 10

endolithic
lichen

Question 11

Vegetal organism forming small, soft and green cushions of
centimetric size.

Answer 11

moss

Question 12

look generally like dense micro-leaves (sub- to millimetric size) tightly packed together. they often grow on stone
surface open cavities, cracks, and in any place permanently or frequently
wet (masonry joints), and usually shady

Answer 12

moss

Question 13

develop brown rhizines and may create a micro-soil zone
between the stone surface and the green part

Answer 13

mosses

Question 14

often change morphology and color under lack or excess of
water. During dry periods of the year, the cushions shrink, become
harder and brittle, and their colour turns to brown

Answer 14

mosses

Question 15

Microscopic fungus which colonies, to the naked eye, look like a
downy film or a network or star-like millimetric patches of filaments of
diverse colours (white, grey, black)

Answer 15

mold

Question 16

by their filamentous and/or chain-like growth may penetrate
several centimeters into the stone substrate

Answer 16

moulds

Question 17

Vegetal living being, having, when complete, root, stem, and leaves,
though consisting sometimes only of a single leafy expansion (e.g. Tree,
fern, herb)

Answer 17

plants

Question 18

If buildings are not maintained, they will eventually colonise places
where water is accessible, extending roots into joints and fractures. As
the roots grow they can widen these joints and cracks and break the
stone.

Answer 18

plants

Question 19

They may also contribute to keep areas damp. This in turn,
exacerbates other processes such as salt deterioration

Answer 19

plants