§ 18.3  DEFINITIONS.
   As used in this zoning code, unless the context clearly indicates otherwise, certain words and phrases shall mean the following.
   CALIPER. The diameter of a tree trunk measured four and one-half feet above the ground. Also known as DIAMETER AT BREAST HEIGHT (DBH).
   CONIFER. A plant that produces cones such as a plant belonging to the family Coniferae, such as pines, cypresses, junipers and cedars.
   DECIDUOUS. A plant that loses its leaves annually at the end of the growing season.
   DEFENSIBLE SPACE. The area between a structure and a potential oncoming wildfire where the vegetation has been modified to reduce the wildfire threat and which provides an opportunity to effectively defend the structure. This is also known as SURVIVABLE SPACE.
   DRIP LINE. An area around the tree trunk that generally includes the spread of the tree branches. Italso may refer to that area around a structure that is beneath the roof overhang.
   DROUGHT TOLERANT. Non-native species that can survive extended periods of time with little or no water.
   EVERGREEN. A plant that retains its needles or leaves all year long, although losing some of the older leaves regularly throughout the year.
   GROUND COVER. Low growing plant materials intended to spread over the ground, and which typically grow to a height of two and one-half feet or less. Also, organic or inorganic materials such as bark, crushed rock, cinders or other similar materials typically use in landscaped areas between plantings.
   INVASIVE SPECIES. An alien (non-native) species whose introduction does or is likely to cause economic or environmental harm or harm to human health and which tend to disrupt natural ecosystems by displacing native species.
   LANDSCAPE AREA. The part of the property exclusively set aside for living plant materials and associated non-living ornamental materials such as mulch, fencing, walls or decorative rock.
   NATIVE PLANTS. Plant species occurring naturally and native to a given ecosystem or plant community.
   NOXIOUS WEEDS. Plant species designated as such by the Secretary of Agriculture, Secretary of the Interior or by state law or regulation. Generally, NOXIOUS WEEDS will possess one or more of the characteristics of being aggressive and difficult to manage, parasitic, a carrier or host of serious insects or disease, and being non-native or new to or not common to the United States or parts thereof. NOXIOUS WEED species have extensive and costly impacts on human health, safety, commerce, recreation and general well-being. NOXIOUS WEEDS can adversely affect food production, wilderness values, wildlife habitat, visual quality, forage production, reforestation, recreational opportunities, natural wildfire regimes and land values.
   PLANT UNIT. A method of identifying landscaping requirements. Alternative plant units are set forth in § 18.7.
(Ord. 2012-04, passed 12-5-2012)