THE MARSH at DEN ROCK PARK Lawrence, Massachusetts BOTANICAL RESOURCE INVENTORY & MANAGEMENT RECOMMENDATIONS Produced by: Bruce M. Patterson North Andover, Massachusetts November 2006 CONTENTS ACKNOWLEDGEMENTS............................................................................................... iv SECTION 1 – EXECUTIVE SUMMARY ........................................................................ 1 Purpose....................................................................................................................................... 1 Distribution................................................................................................................................ 1 Summary of Findings................................................................................................................ 1 Concerns..................................................................................................................................... 2 Recommendations ..................................................................................................................... 2 SECTION 2 – INVENTORY ............................................................................................. 3 Introduction ............................................................................................................................... 3 Methodology............................................................................................................................... 3 Site .............................................................................................................................................. 3 Location.................................................................................................................................................3 Study Area .............................................................................................................................................4 Ownership..............................................................................................................................................5 Public Access.........................................................................................................................................5 Physical Nature.......................................................................................................................... 6 Topography............................................................................................................................................6 Geology .................................................................................................................................................6 Soils .......................................................................................................................................................6 Hydrology..............................................................................................................................................7 Land-use History ...................................................................................................................................8 Botanical Survey........................................................................................................................ 9 Method...................................................................................................................................................9 Plant Communities.................................................................................................................................9 Marsh Areas.........................................................................................................................................10 Central Marsh, M(C) ...........................................................................................................................10 Eastern Marsh, M(E) ...........................................................................................................................11 River Birch Swamp, RBS ....................................................................................................................12 Red Maple Swamp, RMS ....................................................................................................................13 Successional Forest, SF(E), SF(W) .....................................................................................................14 Mixed Deciduous Forest, E(E), E(S), E(SE), E(W).............................................................................15 Mixed Oak Forest, OF .........................................................................................................................15 Vernal Pools ........................................................................................................................................16 Special Plants.......................................................................................................................................16 Spatulate-leaved Sundew (Drosera intermedia).............................................................................16 Nodding Ladies’ Tresses (Spiranthes cernua)................................................................................16 Golden Pert (Gratiola aurea)..........................................................................................................17 Lance-leaved violet (Viola lanceolata)...........................................................................................17 Small-flowered Gerardia (Agalinis paupercula).............................................................................17 The Marsh at Den Rock Park, Botanical Resource Inventory & Management Recommendations, November 2006 ii SECTION 3 – ANALYSIS AND RECOMMENDATIONS ........................................... 21 Values ....................................................................................................................................... 21 Ecological ............................................................................................................................................21 Recreational.........................................................................................................................................21 Educational ..........................................................................................................................................21 Aesthetic ..............................................................................................................................................21 Concerns................................................................................................................................... 21 Invasive plants .....................................................................................................................................21 Area misuse .........................................................................................................................................22 Abutter impact .....................................................................................................................................22 Hydrology............................................................................................................................................22 Succession ...........................................................................................................................................22 Recommendations ................................................................................................................... 22 Encourage proper use ..........................................................................................................................22 Manage invasive plants........................................................................................................................23 Educate abutters...................................................................................................................................23 Conclusion................................................................................................................................ 23 REFERENCES ................................................................................................................ 24 Physical Nature....................................................................................................................................24 Plant Communities...............................................................................................................................24 Plant Species........................................................................................................................................24 APPENDIX A – Vascular Plant List by Botanical Name.............................................. 26 APPENDIX B – Vascular Plant List by Plant Family ................................................... 33 APPENDIX C – Vascular Plant List by Plant Community............................................ 42 The Marsh at Den Rock Park, Botanical Resource Inventory & Management Recommendations, November 2006 iii ACKNOWLEDGEMENTS This report is the final project for my Advanced Certificate in Field Botany/Floristics from the New England Wild Flower Society. Sincere thanks to the Director of Education Greg Lowenberg, my teacher Francis Clark who taught me about wetlands and botanical inventory methodology, and the many other instructors