Lippia
This Weed Risk Management Assessment uses a series of questions to arrive at scores for weed risk and feasibility of coordinated control for this weed, and displays the necessary management actions derived from these scores.
This information is then used to make decisions about the introduction, prioritisation and status of this weed in New South Wales.
| Weed (Scientific name) | Phyla canescens | ||
| Weed (Common name) | Lippia | ||
| Region | All of NSW | ||
| Management area | Grazing areas | ||
| Landuse | 2.1 Grazing natural vegetation | ||
| Assumptions | Lippia (Verbenaceae). Grazing areas across all of NSW are predominantly unimproved pastures.Standard weed management is limited. In the east pasture management for competitive pastures and varying stocking rates are most common. Fertiliser application is common in the east in some places. Herbicide application may be used as well as cultivation and resowing of areas. Limited use of broad-scale herbicide applications and cultivation in the west. Density in land use: high. | ||
| Weed Risk | |||
|---|---|---|---|
| Invasiveness | Score Total | Answers | Source and comments |
| Q1. What is the ability of the weed to establish amongst existing plants? | 1.0 | Seedlings establish after moderate disturbance | P. Welchman personal observations. |
| Q2. What is the weed's tolerance to average weed management practices in the land use? | 3.0 | 95% + weeds survive common management | Personal observations. |
| Q3. What is the reproductive ability of the weed in the land use? | 3.0 | Leigh and Walton (2004). | |
| (a) Time to seeding | 2.0 | 1 year or less | |
| (b) Annual seed production | 1.0 | Low | |
| (c) Vegetative reproduction | 2.0 | Frequent | |
| Q4. How likely is long-distance dispersal (>100m) by natural means? | 1.0 | Leigh and Walton (2004). | |
| (a) Flying animals | 0.0 | Unlikely | |
| (b) Other wild animals | 0.0 | Unlikely | |
| (c) Water | 2.0 | Common | |
| (d) Wind | 0.0 | Unlikely | |
| Q5. How likely is long-distance dispersal (>100 m) by human means? | 2.0 | Leigh and Walton (2004). | |
| (a) Deliberate spread by people | 1.0 | Occasional | |
| (b) Accidentally by people and vehicles | 1.0 | Occasional | |
| (c) Contaminated produce | 1.0 | Occasional | |
| (d) Domestic/farm animals | 1.0 | Occasional | |
| Total | 6.7 | ||
| Impacts | Score Total | ||
| Q1. Does the weed reduce the establishment of desired plants? | 3.0 | > 50% reduction | Leigh and Walton (2004). |
| Q2. Does the weed reduce the yield or amount of desired vegetation? | 4.0 | > 50% reduction | Leigh and Walton (2004). |
| Q3. Does the weed reduce the quality of products, diversity or services available from the land use? | 2.0 | Medium | Leigh and Walton (2004) and Coutts-Smith and Downey (2006) - threatens Coolibah and box woodland - an EEC. |
| Q4. What is the weed's potential to restrict the physical movement of people, animals, vehicles, machinery and/or water? | 0.0 | None | Leigh and Walton (2004). |
| Q5. What is the weed's potential to negatively affect the health of animals and/or people? | 1.0 | Low | Leigh and Walton (2004). |
| Q6. Does the weed have major positive or negative effects on environmental health? | 2.0 | a., b., e. and f. Leigh and Walton (2004). C. and d, 'Do not know' . | |
| (a) food/shelter | 0.0 | Minor or no effect | |
| (b) fire regime | 0.0 | Minor or no effect | |
| (c) altered nutrient levels | ? | Do not know | |
| (d) soil salinity | ? | Do not know | |
| (e) soil stability | 1.0 | Major negative effect | |
| (f) soil water table | 1.0 | Major negative effect | |
| Total | 6.3 | ||
| Potential distribution | |||
| Q1. Within the geographic area being considered, what is the percentage area of land use that is suitable for the weed? | 8.0 | 60-80% of land use | Estimate. |
| Comparative weed risk score | 337 | ||
| Weed risk category | Very high | ||
| Feasibility of coordinated control | |||
| Control costs | Score Total | ||
| Q1. How detectable is the weed? | 2 | Leigh and Walton (2004). | |
| (a) Distinguishing features | 0 | always distinct | |
| (b) Period of year shoot growth visible | 0 | > 8 months | |
| (c) Height at maturity | 2 | <0.5 m | |
| (d) Pre-reproductive height in relation to other vegetation | 2 | below canopy | |
| Q2. What is the general accessibility of known infestations at the optimum time of treatment? | 0 | high | Leigh and Walton (2004). |
| Q3. How expensive is management of the weed in the first year of targeted control? | 2 | Leigh and Walton (2004). | |
| (a) Chemical costs/ha | 1 | low (< $100/ha) | |
| (b) Labour costs/ha | 2 | medium ($100-$249/ha) | |
| (c) Equipment costs | 1 | low | |
| Q4. What is the likely level of participation from landholders/volunteers within the land use at risk? | 2.0 | low | Leigh and Walton (2004). |
| Total | 5.0 | ||
| Persistence | Score Total | ||
| Q1. How effective are targeted management treatments applied to infestations of the weed? | 3 | low | Leigh and Walton (2004). |
| Q2. What is the minimum time period for reproduction of sexual or vegetative propagules? | 3 | < 6 months | Leigh and Walton (2004). |
| Q3. What is the maximum longevity of sexual or vegetative propagules? | 1 | 2-5 years | L. Tanner personal communication. |
| Q4. How likely are new propagules to continue to arrive at control sites, or to start new infestations? | 2.0 | Leigh and Walton (2004). | |
| (a) Long-distance (>100m) dispersal by natural means | 2 | frequent | |
| (b) Long-distance (>100m) dispersal by human means | 1 | occasional | |
| Total | 8.2 | ||
| Current distribution | |||
| Q1. What percentage area of the land use in the geographical area is currently infested by the weed? | 4.0 | 20-40% of land use | Estimate. |
| Q2. What is the number of infestations, and weed distribution within the geographic area being considered? | 2.0 | widespread | Personal observations. |
| Total | 5.0 | ||
| Comparative feasibility of coordinated control score | 205 | ||
| Feasibility of coordinated control category | Negligible | ||
| Management priority category | Manage weed | ||
| Calculation of overall uncertainty score | 2% | ||
| Positive Impacts | Supposedly reduced fire risk in forestry but no evidence found in NSW. Used as a drought tolerant broad leaf lawn. Use in honey production by apiarists? Does it have any grazing value? | ||
| References/Other comments | |||
|
Coutts-Smith, A. J. and Downey, P. O. (2006). The impact of weeds on threatened biodiversity in NSW. Technical series no.11. CRC for Australian Weed Management Systems, Adelaide. 100 pp. Leigh, C. and Walton, C. S. (2004). Lippia (Phyla canescens) in Queensland. Queensland Department of Natural Resources and Mines, Brisbane. 34 pp. Assessment by Dr Stephen Johnson, Weed ecologist, I&I NSW, 17 May 2010. This assessment does not include riparian areas that are not grazed. | |||
