Growing Degree Days

A Growing Degree Day is any day in which the average temperature is above a specified base temperature, which is given for a particular subject matter. Growing Degree Days is an accumulation of these days and their values which are above the base temperature, providing an accumulated heat value. An example might be the average temperature of a day, in say April, being 10°C, and if the base temperature is given as 5°C, then for that day it is 5 GDD. The starting period for monitoring GDD might typically be March or April, through to the end of October or November. The value of recording GDD

Continue reading about this

  Growing Degree Days (GDD)

An accumulation of mean temperature figures to aid estimating when grasses might come into flower and produce seed heads and for the application of a plant growth regulator, if deemed appropriate. GDD can also be used for estimating different stages of pest development to help in determining suitable control methods. The maximum and minimum daily temperatures are summed and then divided by two, with the base temperature being deducted to produce the required figure.

  Growing Season Length

The number of days where the average temperature is above 5C in the first period of the year of 6 continuous days up to when the average temperature drops below 5C for 6 continuous days, with the latter period only being counted after 1st July. The long-term average UK growing season length, for the period 1961 – 1990 was 275.9 days, compared with 298.4 days for the period 1991 – 2020.

  Gymnospermae

The group (previously a Division, but more commonly now just referred to as a Clade, being unranked) of exposed-seed-bearing plants, in which the ovules are not enclosed within an ovary, within the Spermatophyte Clade (sometimes given as a superdivision). It is split into four Divisions: 1. Conifers (Pinophyta / Coniferophyta). 2. Cycads (Cycadophyta). 3. Ginkgo (Ginkgoales). 4. Gentophytes (Gnetophyta).

  Habitat

The place where an organism lives. A habitat can typically consist of several ecological niches. A micro-habitat might be considered a layer within a habitat canopy, for example, one organism may live at ground level, another halfway up a plant, whilst another may live in the higher canopy of a plant.

  Habitat Classification

The different physical characteristics of an area in which plants and animals live. Larger groupings are then divided into sub-groups. A habitat classification system is used for Phase 1 and Phase 2 surveys and can be grouped as follows: • Major habitat types / categories: Phase 1 = 10; Phase 2 = 12. • Habitat types / communities: Phase 1 = 155; Phase 2 = 286. • Total sub-communities: Phase 1 = Not applicable; Phase 2 = 578. Phase 1 classification (Major types) A. Woodland and scrub. B. Grassland and marsh. C. Tall herb and fen. D. Heathland. E. Mire. F. Swamp, m

Continue reading about this

  Hand Shearing

The use of hand shears to cut awkward or small areas of relatively long grass which are not easily cut with the use of a mower or grass trimmer, or where it is not worth the effort of deploying a mower or trimmer to cut the grass. Hand shearing might typically be carried out on easily reached (by hand) embankments, around saplings or relatively newly planted trees.

  Handling and Searching for Plants

When looking for plants to identify or photograph there are a few important, but simple, safety precautions to take. Some plants, if touched or handled incorrectly, can cause physical injury, irritation and poisoning. If you are venturing into undergrowth it is important that you wear suitable clothing and PPE to protect your skin. Prickles, such as stinging nettles can be particularly irritating and can cause inflammation of an area of skin exposed to the nettle. Thorns, such as roses, hawthorn, blackthorn or pyracantha can penetrate the skin fairly easily, so be careful if working a

Continue reading about this

  Heavy Metal

Metallic elements which can be toxic to plants and can result in significant thinning or death or a turfgrass sward, even in very small quantities. Examples include Zinc and Copper, which are also essential micro-nutrients.

  Heteroecious

An organism that completes different stages of its lifecycle on different hosts, with two or more different host species being required. The rust species Puccinia striiformis causes stripe (yellow) rust in some cereal and other grasses. It is heteroecious with Berberis species being a host along with grasses including wheat, rye, barley, smooth stalked meadow grass and others. (Huang, S., Zuo, S., Zheng, D. et al. Three formae speciales of Puccinia striiformis were identified as heteroecious rusts based on completion of sexual cycle on Berberis spp. under artificial inoculation. Phytopathol Re

Continue reading about this