that take up considerably more water than grasses and shrubs all year around. They deplete run-off in catchment areas and water flow in rivers. This depletes the resources available for other species in the environment. P. pinaster tends to grow rapidly in riparian zones, which are areas with abundant water where trees and plants grow twice as fast and invade. P. pinaster takes advantage of the water available and consequently reduces the amount of water in the area available for other species. The fynbos catchments on the Western Cape of South Africa are a habitat negatively affected by P. pinaster. Twenty-three years after planting the pines, there was a 55% decrease in streamflow in this area. Similarly, in KwaZulu-Natal Drakensberg there was an 82% reduction in streamflow 20 years after introducing P. pinaster to the area. In the Mpumalanga Province, 6 streams completely dried up 12 years after grasslands were replaced with pines. To reinforce that, there is a negative effect from the invasive species P. pinaster, these areas of dense P. pinaster were thinned and the number of trees in the area decreased. As a result, the streamflow in the fynbos catchments of the Western Cape increased by 44%. The streamflow in the Mpumalanga Province increased by 120%. As a result of P. pinaster growth, there is often less understory vegetation for livestock grazing. Once again there was a positive effect when some of the pines were removed and agreeable range grasses were planted. The grazing conditions for the sheep of the area were greatly improved when the P. pinaster plantation was thinned to 300 trees per hectare. The invasion of P. pinaster leads to the decrease of understory vegetation and therefore a decrease in livestock. It is sporadically naturalizing in Oakland and San Leandro in northern California. Ecological interactions Pinus pinaster is particularly successful in regions with fynbos vegetation because it is adapted to high-intensity fires, thus allowing it to outcompete other species that are not as well adapted to high-intensity fires. In areas of fire-prone shrubland, the cones of P. pinaster will release seeds when in a relatively high-temperature environment for germination as a recovery mechanism. This adaptation increases the competitive ability of P. pinaster amongst other species in the fire-prone shrubland. In a 3-year observational study done in Northwestern Spain, P. pinaster showed a naturally high regeneration rate. Observations showed a mean of 25.25 seedlings per