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Description
This programme deals with the climate and some of the organisms which live in hot deserts. The general features of climate and the terrain are described with particular reference to the low and irr...egular rainfall and temperature fluctuations. The adaptations of different kinds of flowering plants to the varying habitat types is described. Ephemerals, deep rooted forms, succulents and subterranean 'window plants' are shown. The behavioural and structural adaptations of animals to the extreme physical conditions of hot deserts is illustrated: the relationships between diet, patterns of activity and diurnal temperature fluctuations are demonstrated with a range of small rodents and lizards which live in sand and rock habitats.
Metadata describing this Open University video programme
Module code and title: S323, Ecology
Item code: S323; 10
First transmission date: 20-06-1974
Published: 1974
Rights Statement:
Restrictions on use:
Duration: 00:24:30
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Producer: Neil Cleminson
Contributors: Wilma George; Irene Ridge
Publisher: BBC Open University
Keyword(s): Climate; Ephemerals; Flowering plants; Irregular rainfall; Lizards; Organisms; Rodents; Sand & rock habitats; Temperature fluctuations; Terrain
Subject terms: Desert ecology
Footage description: Satellite shot of the earth showing the North African desert through cloud cover. Several still shots of desert areas. Commentary by Irene Ridge introduces the programme which will examine hot desert climate and the organisms that live in it. Irene Ridge defines a desert climate. Still shots of the Libyan desert, one showing a flash flood. Irene Ridge with a cross-section diagram of a desert area explains the two different habitats. (Waddis and Plateaux) which exist in deserts. She explains also how flash floods occur. Irene Ridge begins her discussion on the adaptation of different kinds of flowering plants to the two habitats described above. She shows an ephemeral plant, a California poppy (Eschscholtzia californica) and explains how it survives. Shots of acacia plants (Acacia Senegal) in a waddi. Irene Ridge explains how it has adapted to its habitat. Shots of acacia root system and of a desert soil diagram. Irene Ridge next examines plants which live on the desert plateau where they cannot tap underground reservoirs. Shots of storage succulents (cacti) on the Arizona desert. Shots of desert wrens and an elf owl which live among the cacti. Shots of a cactus being cut open to provide a man with drinking water. Irene Ridge in the studio with a barrel cactus She points out its various features. She then cuts open a small cactus and examines its internal features. Ridge next shows an example of parallel evolution - an Arizona cactus and African euphorbia. Irene Ridge examines the desert adaptation of the subterranean window plant (Haworthia pilifera) Several shots of Haworthia pilifera. Ridge examines the desert adaptations of other haworthia which do not have window leaves. Electron micrographs of the leaf cuticle and stomata spore of an ordinary tropical plant and a desert haworthia. Ridge explains how water is conserved in haworthia. She uses a diagram of a stomatal pore cross section to aid. Wilma George holds a haworthia plant and a scorpion. She introduces her discussion on animal adaptations to hot desert conditions. She explains how she goes about doing her research field work in the desert. Shots of a time/temperature graph which she uses to illustrate and quantify temperature and animal activity over a 24 hour period. The graph above shows, over a 24 hour period, the temperatures of the surface sand and the temperature 20 cm below the sand. Shots of a desert rodent, Meriones hurrianae, in a laboratory cage. Wilma George examines the activity cycle of this animal. The results are shown on the time/temperature graph. Shots of gerbils (Gerbilles pyramidum). Wilma George examines the activity cycle of this animal which is shown on the time/temperature graph. Field shots of a nocturnal rodent jerboa (Juculus jaculus). Wilma George examines the activity cycle of the animal. Which is shown on the time/temperature graph. Wilma George next examines desert animals which live among the rocks rather than in the sand. Shots of the time/temperature graph for the rock environment showing temperature variations over a 24 hour period. Shots of gundies (Stenodactylus vali). Wilma George examines the activity cycle of this animal. This is shown on the time/temperature graph. Shots of the girdle, tailed lizard (Cordylus sp.) Wilma George examines the activity cycle of this animal which is shown on the time/temperature graph. Shots of spiny mice (Acomys cahirensis) in the laboratory. Wilma George examines the activity cycle of this animal, nocturnal which is shown on the time/temperature graph. She then explains some methods which are used to study nocturnal animals in the field. Wilma George sums up. She discusses the direction of her future research in adaptations of desert animals.
Production number: 00525_1132
Videofinder number: 1034
Available to public: no