| BEN |
| BOTANICAL ELECTRONIC NEWS |
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| ISSN 1188-603X |
| No. 463 January 25, 2013 | aceska@telus.net | Victoria, B.C. |
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From: Frank Lomer lomerlomer@hotmail.com
Paspalum is a grass genus of 300-400 species, most of which are native to the Western Hemisphere (Charles M. Allen & David W. Hall, 2003). The only species of this genus thought to occur in British Columbia has been Paspalum dilatatum Poir. (dallisgrass) which is native to Brazil and Argentina. It occurs in BC as an alien in landscape plantings in Terry Hughes Park, New Westminster (Lomer 6385 UBC), collected in 2007. It is not clear if this single clump was planted. Judging by the location and the fact that it is often mowed down it seems likely to have arisen as a contaminant in the topsoil when the area was first landscaped. It still exists at that site today.
On September 16, 2012 I found another species of Paspalum in British Columbia, Paspalum distichum (knotgrass, Thompson grass), at a stream outlet to a sandy ocean shore at Long Beach in Pacific Rim National Park Reserve, British Columbia (Lomer 8162). It formed a dense 5 x 10 m patch around a sandy rise where the stream turned at the beach front. It grew with Trifolium wormskioldii Lehm., Carex obnupta Bailey and a small clump of Leymus mollis (Trin.) Pilger. Dozens of stems with flowering and fruiting branches in varying stages of development were produced, making identification easy. In this species spikelets are borne in two rows rather sunken in on one side of the rachis. The spikes are generally in terminal pairs or occasionally a third pair is produced below the top pair. This arrangement is not often seen in BC grass species; only crabgrass (Digitaria spp.) and Bermuda grass (Cynodon dactylon (L.) Pers.) are similar in this way, the latter species being extremely rare in BC.
The most striking feature of this grass is the long leafy stolons it produces when colonizing open sites (Lomer 8161). These horizontal stems can stretch for more than two metres late in the growing season and such plants can be encountered at Long Beach at the upper reaches of the pure sand beach distant enough from regular tidal inundation. These plants seem to arise from seed or fragments dispersed from the only known seed-producing population at the outlet stream mentioned above. They are quite distinctive robust tropical-looking plants with broad short blades and few widely spreading lax stems that sprout roots at a few nodes on the compacted sand beach. These plants don't produce flowering stems, but spend their energy stretching out in all directions and planting roots. They inevitably get washed away in the winter storms.
Paspalum distichum is widespread in the world, known mostly from warm regions, and often as a weedy introduction. In North America it is known throughout the southern United States, north up both coasts to New Jersey and Washington. In Washington it is generally considered a native grass though with a weedy habit and its native status is hard to assess (Peter Zika and Barbara Wilson, personal communication). In British Columbia, Paspalum distichum will be considered a native grass because it grows in a natural area, is not mixed with other introduced species, is in typical habitat of wet streamsides (fertile population), and is one of many native species that extend up the coast from the United States, just making it into British Columbia on Vancouver Island.
I had also collected Paspalum distichum in British Columbia prior to 2012 from two other sites near the two mentioned above, but I had misidentified the specimens as Cynodon dactylon because they lacked any flowering stems. The first was taken on August 2, 2004 from Schooner Cove, Pacific Rim National Park (Lomer 5387 UBC) from compacted fine sand on the ocean beach, about 1 km southwest of Lomer 8162 from 2012. This site is actually from the east side of Schooner Cove on Long Beach itself. The second was taken later the same day from the same habitat 50 m east of the Long Beach parking lot, 500 m east of Lomer 8162.
At present, Paspalum distichum is only known in BC from the 4 sites mentioned above, all with vouchers, and all on the sandy beach of Long Beach in Pacific Rim National Park. The eastern and westernmost collections are 1.5 km apart and only one fertile patch is known. A thorough survey of the Long Beach area along the beach in September when this species is mature, focusing on stream outlet habitats, is recommended. The Native village to the west of Long Beach should have good habitat, but this area was not surveyed. As well, this species may be expected on other sandy beach stream outlets further north and south in Pacific Rim National Park. The Royal BC Museum herbarium in Victoria should also be searched for misidentified specimens. This grass seems easy to find on Long Beach and no doubt others have come across it over the years, if it truly is a native and not a recent introduction. However, it is rather inconspicuous in the streamside habitat and the waif plants on the beach are lacking in features to help identify it. Pasplalum distichum is also late-flowering, so early season searching may prove fruitless.
Both Lomer 8161 and 8162 will be deposited in the UBC herbarium with several duplicates going to other herbaria in Canada and the US.
UBC V230078 - Paspalum distichum L. - Canada, British Columbia, Vancouver Island, Pacific Rim National Park, Schooner Cove, beach at end of trail, west of Native settlement. 49 deg 04' 07" N 125 deg 47' 02" W; habitat: ocean beach, in compacted fine sand, with Rumex fueginus Phil., Agrostis stolonifera L.; elev.: sea level; August 2, 2004; Coll.: Frank Lomer Collection No.: 5387 Originally identified as Cynodon dactylon, reidentified to Paspalum distichum by Frank Lomer, October 2012.
UBC V230080 - Paspalum distichum L. - Canada, British Columbia, Vancouver Island, Pacific Rim National Park, Long Beach, 50 m east of parking area. 49 deg 04' 20" N 125 deg 45' 51" W; habitat: ocean beach, in fine compacted sand; elev.: sea level; August 2, 2004; Coll.: Frank Lomer Collection No.: 5389 Originally identified as Cynodon dactylon, reidentified to Paspalum distichum by Frank Lomer, October 2012.
Paspalum distichum L. - Canada, British Columbia, Pacific Rim National Park, Long Beach, 340 m due west of washrooms at Long Beach parking lot. 49 deg 4' 21.2" N 125 deg 46' 19.6" W; habitat: Flat, clean, firm sand near driftwood, with Ambrosia chamissonis (Less.) Greene, Rumex fueginus, Agrostis stolonifera; elev.: 1 m; September 16, 2012; Coll.: Frank Lomer Collection No.: 8161
Paspalum distichum L. - Canada, British Columbia, Pacific Rim National Park, Long Beach, 375 m due west of washrooms at Long Beach parking lot. 49 deg 4' 21.2" N 125 deg 46' 21.5" W; habitat: Sandy rise by stream outlet onto sandy sea beach, with Trifolium wormskioldii, Carex obnupta, Leymus mollis (small clump); elev.: 1 m; September 16, 2012; Coll.: Frank Lomer Collection No.: 8162.
The absence of well-executed environmental monitoring in the Athabasca oil sands (Alberta, Canada) has necessitated the use of indirect approaches to determine background conditions of freshwater ecosystems before development of one of the Earth's largest energy deposits. Here, we use highly resolved lake sediment records to provide ecological context to ~50 y of oil sands development and other environmental changes affecting lake ecosystems in the region. We show that polycyclic aromatic hydrocarbons (PAHs) within lake sediments, particularly C1-C4–alkylated PAHs, increased significantly after development of the bitumen resource began, followed by significant increases in dibenzothiophenes. Total PAH fluxes in the modern sediments of our six study lakes, including one site ~90 km northwest of the major development area, are now ~2.5–23 times greater than ~1960 levels. PAH ratios indicate temporal shifts from primarily wood combustion to petrogenic sources that coincide with greater oil sands development. Canadian interim sediment quality guidelines for PAHs have been exceeded since the mid-1980s at the most impacted site. A paleoecological assessment of Daphnia shows that this sentinel zooplankter has not yet been negatively impacted by decades of high atmospheric PAH deposition. Rather, coincident with increases in PAHs, climate-induced shifts in aquatic primary production related to warmer and drier conditions are the primary environmental drivers producing marked daphniid shifts after ~1960 to 1970. Because of the striking increase in PAHs, elevated primary production, and zooplankton changes, these oil sands lake ecosystems have entered new ecological states completely distinct from those of previous centuries.
Freely available online through the PNAS open access option: http://www.pnas.org/content/early/2013/01/02/1217675110
"This book is, at heart, a book about wildness and the importance of preserving it." It documents the fascinating biodiversity of the mountain landscapes of eastern North America. It covers the major alpine ecosystems of New England, New York, Quebec, Newfoundland and Labrador. Twenty authors have contributed 22 chapters. This is a lovely book with many colour photos and provides a very helpful overview of the subject area. It also includes a great deal of botanical information.
The Forward emphasizes the extent to which this guide has expanded our vision of alpine in eastern North America and stresses the need to protect wildness, particularly in the more northern areas. The quotes from Leopold and Thoreau reminded me of the legitimacy of a good idea. In the Preface the editors describe the book as a natural history guide "with the hope of contributing in small ways to the development of a constituency for eastern alpine landscapes".
There is a great deal for botanists in this book. An introduction by the editors includes a useful map of eastern North American alpine mountain ranges as well as a section on conservation and a regional outline introducing the various chapters. Chapter 3, "Ice age and after" outlines the recent events that have influenced the flora of alpine areas. The following chapter explains how current weather influences alpine flora. Contrary to what many people think, climate change may not play a prevailing role in alpine habitats because it is wind, clouds and adiabatic cooling that provide some of the major stresses that contribute to the long-term persistence of eastern alpine ecosystems. However changes in composition of alpine vegetation (e.g. Robinson et al. 2010) still do require more explanation and many factors are likely to be involved.
The next chapter on vegetation classifies alpine plant communities into 9 major kinds with two others associated with either serpentine or limestone rocks. Eleven plates are included, each illustrating 8 plants of each of these communities. This chapter also includes some useful information on alpine plant adaptations. Like other chapters in the book, this one is attached to a significant and fairly extensive list of references at the back. There is not enough space in the short chapter on serpentine to cover this fascinating flora completely. One of the most interesting subalpine narrow endemics in eastern North America is the Green Mountain Maidenhair Fern (Adiantum viridimontanum Paris – see Paris 1991) originally known only from subalpine areas in the Green Mountains of Vermont but now also from serpentine outcrops in the boreal and mixed forest of southern Quebec (Centre de données sur le patrimoine naturel du Québec 2008).
The remainder of the book is divided into four parts. The first (Part II) considers sites south of the St. Lawrence: Washington, Katahdin, Albert, and Jacques Cartier. There is a chapter for each of these mountains with a map and a section on access, geology and ecology. These chapters provide a valuable introduction but there is always more that can be said. For example, Fernald (1901) produced a list for Mount Katahdin and this article provides some interesting historical information as well as a plant list and the description of Carex katahdinensis Fernald. (This taxon, most recently treated as conspecific with Carex conoidea Schkuhr ex Willd., still requires more study.) Fernald's (1905) significant report of Rhododendron tomentosum Harmaja (sub Ledum palustre L.) from Mount Katahdin may have been an error since it was not repeated.
Part II concludes with a chapter on some of the smaller alpine sites south of the St. Lawrence. There is an interesting question of whether or not Mount Monadnock, New Hampshire, was completely forested in pre-settlement times. Certainly Baldwin (1974) thought it was but some of his evidence is to the contrary, and he found the treeline to be stable (Baldwin 1977). The text of the Eastern Alpine Guide only lists one of the restricted alpine species present on the top of this very popular mountain. In addition to Minuartia groenlandica (Retz.) Ostenf. there is Vaccinium vitis-idaea L. and Juncus trifidus L., all three recorded by Thoreau in 1858, and a few others in what could pass for an alpine plant community mentioned in Baldwin's earlier (1974) article. The idea that the alpine flora invaded this summit after fires in the early 1800s is an interesting contrast to the idea of the alpine flora elsewhere being relictual.
Mount Desert Island in Maine is another situation where a vegetation at least close to alpine exists on the tops of the higher mountains, but there is something else here that is worth mentioning. The treeless tops of these mountains are some of the most accessible in the east and they offer some of the most spectacular views and a wealth of information is available about the flora (Greene et al. 2005, Gregory et al. 2010). A walk that I did on a Labour Day weekend over three barren hilltops of Sargent Mountain, one of the highest on Mount Desert Island, was unforgettable. http://adventure.nationalgeographic.com/adventure/trips/best-trails/acadia-hike-map/ http://www.lib.utexas.edu/maps/national_parks/acad_95.jpg
Regarding Nova Scotia and New Brunswick, the section on Cape Breton makes the consideration of alpine flora in the northeast more complete, and perhaps the most useful published source is that of Hounsell & Smith (1968). There are a few other references to minor occurrences of alpine plants at some places along the shores of the Bay of Fundy and elsewhere on gypsum cliffs (Roberts 1965, Clayden 1994).
Part III on the alpine areas of Newfoundland could easily be a large book in itself, but the authors have done a good job of summarizing the information. Some of the most accessible sites are listed under "Other alpine sites in Newfoundland." Although much more could be said about any of these sites, a few are particularly worthy of mention. The Hawke Hills for example has served as an important research area for alpine plant ecology, especially concerning Diapensia lapponica. The domed growth was found to trap nutrients, organic matter, heat and moistiure, and different populations were found to flower in either May-June or August (Day & Scott 1981, 1984). The "Northern Limestone Barrens" are well covered in a few pages at the end of this part. This is a particularly significant botanical area. There is a lot of additional information about it on the web. In particular there is a thoroughly outstanding powerpoint presentation by John Maunder ("retired" Curator of Natural History, Newfoundland Museum, St. John's) that is on the website of the Newfoundland and Labrador, Canada, Limestone Barrens Habitat Stewardship Program, http://www.limestonebarrens.ca/ThisWebsite.htm .
Part IV covers alpine sites on the Canadian Shield and includes many places in Quebec and Labrador as well as the Adirondacks of New York, which might have been expected in part II. Not surprisingly the alpine vegetation of the Adirondacks has been extensively studied with regard to change and ecology probably due to ease of access and concerns over human impact. The results of these studies are available in a number of publications listed on the New York Natural Heritage Program website, http://www.acris.nynhp.org/guide.php?id=10015&part=5 . Ketchledge and Leonard (1984) found no vegetation change on Mt. Marcy after 24 years, but there has been destruction of alpine vegetation through human activities at other sites. In a more recent study, Robinson et al. (2010) found a significant replacement of bryophytes by vascular plants. Alpine vegetation is a high priority in New York State because there are only 84 acres.
Again in Part IV the botanist is treated to many spectacular colour images and lists of plants. I had no idea what the alpine areas of some of these mountains were like botanically, but now I do. There is some recent information which will undoubtedly be referenced in an update. For example, the alpine Carex arctogena and Juncus trifidus, are additions to the alpine flora of Monts Groulx, reported by Cayouette et al. (2011) in their extensive account of a recent exploration. This work also includes a discussion of the regionally important plants and a complete listing of botanical surveys in the area. Landry (1969) also produced a list of alpine plants here and discussed phytogeography.
Readers will be pleased to know of the recently established Mealy Mountains National Park Reserve in Labrador, the expectation of Wolverine recovery on Monts Otish, and they will be speculating about why Grizzly Bear recently disappeared from the Torngat Mountains. They will also appreciate the relatively extensive general information on these poorly known wilderness areas. Certainly the forward is correct in stating that a much expanded vision of the alpine in eastern North America will be the result of having this book.
"A Conservation Vision" is the title of the concluding Part V. There are three important observations in this short final chapter: (1) The diverse elevations and aspect gradients in mountain areas contribute to a relatively high biodiversity and these same characters may also act as natural buffers against changing climate. As a result mountain areas can be a sensible choice when it comes to maximizing biodiversity protection. (2) The eastern alpine areas can be enjoyed by many thousands of people. This requires monitoring and management, and there are some excellent examples to draw from such as that of restoration of the endemic alpine Potentilla robbinsiana Oakes ex Rydb.. Remarkably the precursor of the Appalachian Trail was built through the colony of this plant on Mt. Washington in 1819 before the plant was discovered (Graber 1980), yet it remains today near to one of the busiest trails in North America. (3) There is not enough information, and related to this there is a need for more education, scientific research, communication, and planning.
The book concludes with a very extensive and valuable list of references and a complete index to the species listed in the text. With 800 colour photos, it is beautifully illustrated as well as being a very useful source of information. It is also a very pleasant read. Somehow, despite a diversity of authors, a high standard of interesting writing is maintained throughout. The book definitely reaches its goal of helping to conserve nature and natural landscapes. For a biologist it is valuable further education. For any botanist it will be a useful and respected source. Botanical information is accurate and latin names are current and correctly spelled. The extensive involvement of very clever Canadian botanists who are very at home outdoors, including Marilyn Anions, Claudia Hanel, and Luise Hermanutz, has undoubtedly made a difference. Congratulations to the editors on a remarkable job (and they also created one of the publishers).
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