6 WILD PLANTS AND CROPS 1.- How plants live A) The needs of a plant A habitat is the place where a plant lives. Plants need sunlight, water, mineral salts and carbon dioxide to carry out photosyntesis and make their food. Not all plants need the same amount of these elements. B) Sensitivity It is the ability to adapt to changes in the environment.
The roots grow downwards, in search of humidity. The stem and leaves grow towards light.
Some plants can make movements (mimosa). C) The life cycle of plants includes the different stages of its life. 2 groups:
Annual plants complete the life cycle in 1 year. They are born, grow and reproduce in spring and die in the summer. New plants grow again each spring. (poppies, sunflowers, cabbages…) Perennial plants have got a long life cycle. (olive trees, yews…) 2 Types: - Perennial grasses. The visible part of these plants disappears every year but some organs remain underground. - Trees and bushes. They grow throughout their life cycle and grow flowers and seeds in the spring. They can be deciduous or evergreen.
2.- Vegetation Vegetation is all the plants in an area. It is affected by the climate, the relief, the humidity and the soil in this area. Different areas are:
Forests where many trees grow together and need high humidity and fertile soil. Shrubland is an area dominated by bushes. They need poor soil and low humidity. Grassland is an area dominated by grasses with long periods of droughts. In Africa are called savannahs. Desert is an area with arid soil and very little water. There are very few plants. (cactuses) Temperatures can be very high during the day and very low at night.
3.- Crop farming Crop farming is the activity of cultivating plants to obtain crops used for food (cereal, vegetables…), to make other products (fabrics) or to feed animals (hay for cows and sheep). It includes different stages:
Ploughing to prepare the soil.
Sowing Fertilizing to help plants grow. Irrigation Fumigation to stop insects harming the crops. Pruning Harvesting to collect the crops.
According to how much water they need to grow there are 2 types of crops: -
Dry crops (wheat, barley and olive trees) Irrigated crops (corn, tomatoes and rice).
According to the plant type: -
Herbaceous crops that have to be planted every year include cereals and garden plants (tomatoes, lettuces, potatoes…) Trees and bushes are only planted once and include fruit trees, olive trees and vines