Vegetation (Floating River Vegetation) - Office of Public Works
Vegetation (Floating River Vegetation) - Office of Public Works Vegetation (Floating River Vegetation) - Office of Public Works
3.3 General growth characteristics of floating river vegetation Described below are some of the general identification characteristics of frequently observed floating river vegetation during the course of the survey. Milfoil, Myriophyllum spp. and Horned Pondweed, Zannichellia palustris have not been included as they were only seen at one and two locations, respectively. Water Crowfoot, Ranunculus species •Colonisers of gravel riverbeds with limited quantities of deposited sands. •River flow for certain species must be fast, others tolerate slow water. •Flowers are similar in shape to a buttercup but with white petal and yellow middle. •Ranunculus can possess two types of leaves especially during flowering. •Flowering period May to June with vegetative roots development along the stem in August. •Vegetative reproduction takes place in autumn with rising water levels of high flow rate that mechanically break rooted sections of plant stems. Water Parsnip, Berula erecta •Found frequently in maintained drainage ditches. •Along rivers in areas with silt or mud deposits - in the middle of rivers or at the waters edge. •Prefers shallow slow flowing or still water. •Flowers August to September - small white flowers that form a white ball shape. •Can be easily mistaken for Fool’s Watercress, which is often found in same habitat. •Smells of carrots when leaves are crushed. 22
Starwort, Callitriche species •Rooted to channel bases with stems floating upwards. •Starwort resembles a star shape as it grows underwater. •On breaking the waters surface starworts take on a multi-layered star-shaped flower that gently rests on the water surface •Not to be confused with duckweed which is light green and free floating. •Starworts form a mat in the surface usually dark green •Frequently found in drainage ditches, slow moving streams and rivers. •Evidence of reproduction by vegetative means – mechanical shearing of rooted stem. Pondweed, Potamogeton species •Most varied distribution of all the species in terms of water depth •Pondweed was the only floating river vegetation recorded in deep waters. •Broadleaved pondweed was the most frequently observed pondweed species. •Flowering structures were evident on deep-water species between August to September. •Not all pondweed species had floating leaves some species remained completely submerged. •Evidence of reproduction by vegetative means – mechanical shearing of rooted stem 23
- Page 1 and 2: ISSN 1649 - 9840 SERIES OF ECOLOGIC
- Page 3 and 4: Foreword This Ecological Impact Ass
- Page 5 and 6: Executive Summary Table of Contents
- Page 7 and 8: 1.0 Introduction This study was com
- Page 9 and 10: and fauna. The OPW has a multi-annu
- Page 11 and 12: Currently twenty-one Special Areas
- Page 13 and 14: 2.1.4 Lower River Shannon Special A
- Page 15 and 16: 2.2.4 Site elevations within the Lo
- Page 17 and 18: 2.3.4 Site integrity of the Lower R
- Page 19 and 20: 3.0 Ecological Assessment of Water
- Page 21 and 22: 3.2 Distribution and extent of floa
- Page 23 and 24: 3.2.1 Floating river vegetation of
- Page 25 and 26: aquatic moss. 3.2.3 Floating river
- Page 27: 3.2.5 Floating river vegetation wit
- Page 31 and 32: Each form of reproduction requires
- Page 33 and 34: prevented aquatic growth. Water lev
- Page 35 and 36: G.densa was the dominant floating r
- Page 37 and 38: 4.0 Description of maintenance oper
- Page 39 and 40: consultation with the Foreman / Tec
- Page 41 and 42: 4.3 River corridor water dynamics A
- Page 43 and 44: Not shown in the above data set is
- Page 45 and 46: 4.4 Physical, chemical and biologic
- Page 47 and 48: •Survey watercourses to determine
- Page 49 and 50: The primary riverbed substrate of w
- Page 51 and 52: gravel require loosening assess the
- Page 53 and 54: • Livestock should be restricted
- Page 55 and 56: River Breagagh Winter 2006 River Br
- Page 57 and 58: River Breagagh Winter 2006 Ranuncli
- Page 59 and 60: 6.0 Conclusion and summary •Arter
- Page 61 and 62: References •Blamey, M., Fritter,
- Page 63 and 64: Appendix A - Special Areas of Conse
- Page 65 and 66: Lower River Shannon Special Areas o
- Page 67 and 68: Channel name Location coordinates E
- Page 69 and 70: Appendix C - Habitat classification
- Page 71 and 72: Lower River Shannon Special Area of
- Page 73 and 74: Lough Corrib Special Area of Conser
- Page 75 and 76: 7 Lower River Suir Special Area of
- Page 77 and 78: C1 Lower River Shannon Special Area
Starwort, Callitriche species<br />
•Rooted to channel bases with stems floating upwards.<br />
•Starwort resembles a star shape as it grows underwater.<br />
•On breaking the waters surface starworts take on a multi-layered star-shaped flower that gently<br />
rests on the water surface<br />
•Not to be confused with duckweed which is light green and free floating.<br />
•Starworts form a mat in the surface usually dark green<br />
•Frequently found in drainage ditches, slow moving streams and rivers.<br />
•Evidence <strong>of</strong> reproduction by vegetative means – mechanical shearing <strong>of</strong> rooted stem.<br />
Pondweed, Potamogeton species<br />
•Most varied distribution <strong>of</strong> all the species in terms <strong>of</strong> water depth<br />
•Pondweed was the only floating river vegetation recorded in deep waters.<br />
•Broadleaved pondweed was the most frequently observed pondweed species.<br />
•Flowering structures were evident on deep-water species between August to September.<br />
•Not all pondweed species had floating leaves some species remained completely submerged.<br />
•Evidence <strong>of</strong> reproduction by vegetative means – mechanical shearing <strong>of</strong> rooted stem<br />
23
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