Weather and Climate

including microclimate

This page is intended to provide information about the effects of weather and climate on plants and gardening, particularly conditions similar to those experienced in Queensland.

Drought is a major issue in many parts of the country, but there are more factors to consider than just soil moisture, Even if you can irrigate, you may have to contend with high temperatures, intense sunlight (lack of cloud cover), lack of humidity and desiccating winds. This might effect the manner in which you grow your plants, and choice of species. Of course, if you have to cope with these factors AND lack of water, the problems are compounded.

News

North Stradbroke Island preserves rainfall record

Paper-bark tea tree leaves preserved in Swallow Lagoon on North Stradbroke Island have been used to investigate south-east Queensland's weather over the last 7000 years. Using variation in carbon isotope composition, moisture stress experienced by then-growing leaves can be determined. The period 5000 to 6000 years ago was found to be wet, but more variable and increasingly dry about 3000 years ago. Severe droughts during this phase suggests that the probability of something worse than the 1997-2009 Millennium Drought occurring in the future may be higher than the one in 10,000 years currently predicted. It also appears that Queensland was colonised at the end of an unusually wet period, The Little Ice Age (about 1450 to 1850). Source: Preserved leaves reveal 7000 years of rainfall and drought (February 2019)

More Online Information

Older News

Cities scale up pest attack

Recent research recording the incidence in several American cities of a debilitating scale on a species of maple tree predicted larger insect populations in the warmer south than the cooler north. Instead, they found the amount of impervious concrete and asphalt in the vicinity of the tree was more strongly correlated with infestation levels than temperature. Source: Dying Trees in Cities? Blame It on the Concrete (March, 2019)

TV sports coverage captures environmental data

Researchers have been able to analyse plants growing around recognisable landmarks in video footage of Belgian cycle race the Tour of Flanders recorded between 1981 and 2016, scoring leaves and flowers present on specific days. This showed that prior to 1990, few trees had produced their spring foliage in time for the Tour. After that, more and more trees in leaf were visible, correlating with with average temperatures for the area rising about 1.5°C over the period. This method of observing climate and other environmental changes could utilise footage of events like marathons, golf tournaments or open-air festivals in addition to other cycle races around the world. Source: TV coverage of cycling races can help document the effects of climate change, British Ecological Society (July, 2018)

Pollen makes another kind of seed

Pollen particles in the atmosphere were previously thought to be too large to nucleate clouds and that they would settle out too quickly, anyway. However, it's known that pollen grains can break up into fragments which cause allergenic responses in sensitive people. When the affect of moisture on pollen grains was tested, it was found that these can rupture readily into pieces small enough to seed clouds. So, it's possible that a tree's pollen could help make the rain that keeps that tree alive. Source: Pollen and clouds: April flowers bring May showers? (May, 2015)

Temperature effects on plants can be complicated

In cold climates, warm temperatures might be assumed to increase growth. However, a study on two shrub species on an island south of New Zealand showed that episodes of activating warmth during winter are actually detrimental. Elevated respiration, especially by the roots, depletes plant reserves. If this were to occur repeatedly over many years, it could affect on the survival of these species. This indicates one of the unexpected consequences that a warming climate could have on plant life. Shrub growth decreases as winter temps warm up (May 2014)

Seed development sensitive to temperature

Researchers have been studying the effects of elevated temperature on yield of several seed-bearing crop plants. They discovered that seed development is more sensitive than vegetative growth. This means that a plant might grow to its normal size yet fail to set seed adequately. Read more from the Agricultural Research Service here: High Temperatures Could Leave Seed Crops Sterile