User:CareforBees/sandbox

This is a sandbox to work on pollinator decline and climate change in agriculture

Pollinator decline is the reduction in abundance of insect and other animal pollinators in many ecosystems worldwide that began being recorded at the end of the 20th century. Multiple lines of evidence exist for the reduction of wild pollinator populations at the regional level, especially within Europe and North America. Similar findings from studies in South America, China and Japan make it reasonable to suggest that declines are occurring around the globe. The majority of studies focus on bees, particularly honeybee and bumblebee species, with a smaller number involving hoverflies and lepidopterans.

The picture for managed pollinator species is less clear. Although the number of managed honey bee colonies in Europe and North America declined by 25% and 59% between 1985-2005 and 1947-2005 respectively, overall global stocks increased due to major hive number increases in countries such as China and Argentina. Nevertheless, in the time managed honeybee hives increased by 45% demand for animal pollinated crops tripled, highlighting the danger of relying solely on managed pollinators for pollination services.

Pollinators depend on pollen and nectar as food sources. Pollen is a good source of protein and nectar a source of carbohydrates (sugar). Pollinators collect pollen and nectar from flowers and in this process move pollen from flower to flower. Pollen deposited on the stigmas of flowers, germinates, grows down the style to fertilize ovules, that can develop into seeds. Pollinators can move pollen between flowers on a plant, leading to self-fertilization or between flowers on plants which results in outcrossing, also known as cross-pollination. When pollinators move pollen between plant populations and this pollen create seeds, gene flow has occurred. High gene flow between populations tends to homogenize the genetic similarity between populations, rendering them more genetically similar. Since the pollen and nectar provided by plants are the primary food source for pollinators, the possible reduction or disappearance of pollinators has been referred to as an "armageddon" by some journalists.