Arid zones greenhouse

When an area receives no more than 250 mm of rain in the year, the climate is defined as arid. Temperature fluctuations in these parts of the planet are so pronounced that they can exceed 40 °C. What is the first image that these conditions tend to suggest? Almost certainly, one thinks of succulents — the main feature of this final greenhouse — symbolic of the ability to survive arid conditions by using their stems or leaves as reservoirs. The term succulent is applied conventionally to any plant having a succulent stem covered with spines: all have in common the use of similar survival strategies, but in reality there are different genuses found even in remote parts of the planet. Besides these, in arid climates, there are annual species that compress their life cycle into the short periods when water is available and survive the dry season protected in those survival capsules that are their seeds; certain perennials dry up the aerial part of their structure while keeping the undersoil part alive; yet other plants have adapted their organisms to withstand drought by reinforcing evergreen leaves with hydrophobic cuticles and expanding their root systems. When thinking of hot arid climates the mind turns instinctively, for example, to the 9,400,000 km² of the Sahara desert, but in the heart of central Asia, stretching from the Caspian Sea to Mongolia, is the largest cold arid region in the world, where winter temperatures can plunge as low as minus 30 °C.