Diario del proyecto Paradise Park, Windsor VT

Lake Runnemede is slowly coming back to life after a very long winter. The Lake did not completely freeze over again this winter, which has been true, I think, for four of the past five winters (since I've been looking). The western shore of the lake remains open except for extreme cold snaps (sustained below zero temps), almost certainly because there are 30+ springs along that shore line that pump very calcareous, 45-degree water into the lakes (1.8 million gallons per day). Although vegetation in that area is sparse (due to lack of nutrients in the ground water, the primary "macrophyte" in that area are really charophytes), there is probably enough light coming into the lake to keep nearby floating strands of Coontail (Ceratophyllum demersum) vital through the winter. Ice fisherman reported a few strands of green Coontail fouling their hooks this winter and there were both small fronds and winter buds (balls of green meristems) in the water on March 15, while most of the Lake was still frozen over. At any rate, the first producers that appear in the Lake in noticeable amounts are the filamentous green algae (FGA) that was also present on March 15 and which have formed noticeable blooms along the bottom of the Lake since that time. Over the past week, we've noticed that the FGA has become aerated and is forming floating mats here and there. The spring air (and presumably water) temperature rise had been very gradual through April and early May, but has spiked up into the 80's over the past few days. Macrophytes are starting to appear now as well. In addition to the annual rising of the water lilies (Nymphaea odorata ssp., tuberosa), small rooted pondweeds (Potamogeton ssp.), water starworts (Zosterella dubia) and eelgrass (Vallisneria americana) are also popping up out of the substrate. The rooted macrophytes, particularly the Pondweeds (four species/hybrids of pusilloid or narrow-leaved pondweeds) are extremely challenged in this Lake by a number of environmental (mainly anthropogenic) factors. By late July, the rooted macrophytes will become weighted down by marl (calcium carbonate deposits) and will be outcompeted for by light from the ever-increasing Coontail populations and will therefore have a truncated growing season. Aquatics seem adaptable enough to pull this off - in general the two primary species of Pondweeds (P. foliosus and P. hillii) typically flower and fruit by mid-June, which is 2-3 weeks earlier than in other lakes and ponds in this area. While several rooted macrophytes form dense enough stands to be able to fend off the Coontail incursion (Stuckenia pectinata, V. americana, Z. dubia and P. foliosus) - presumably by producing rhizomes, the primary means of propagation for most of them appear to be either by seed (V. americana) or winter bud (Potamogeton spp.). The hybrid Potamogetons occasionally produce flowers and fruit, but are sterile and spread only by winter bud. Surprisingly, this plant has successfully remained in this lake for at least 135 years and perhaps for millenia.

The beaver completed construction of a new lodge on the western arm of the Lake during the fall and winter. Ann had noted that they had moved from their old lodge on the western shore and build a large burrow near the roots of a fallen tree last year, and they improved on it significantly over the winter. Last summer, I also noticed that they had been cutting significant channels along the lake bottom in that area. It is unknown whether or not they still occupy the old lodge.

There is also some activity by a young beaver (2-year-old?) on the eastern side of the Lake, in the Pulk Hole Brook wetlands. It/they built a small dam across the brook in one or two places, and there are burrows in the bank downstream of one of the dams. There is no danger of them damming this brook to the point of flooding so long as they stay clear of the culvert that runs under Route 5 near the parking lot of the strip mall across the road. There were a large number of beaver cuttings on the downstream side of the culvert, but none on the upstream side, which is protected by a beaver baffle. That activity may or may not from the same beaver(s) - there have been no reports of beavers crossing Route 5, although they may actually be able to access the culvert by going around the beaver baffle.

They do appear to carefully choose their sites with a fair amount of complexity of thought. Both of the lodges on the western side of the Lake were located near springs which ensure a constant supply of fresh water and help them to moderate temperatures in the lodge year-round. Both lodges are also located near the large water lily (Nymphaeae odorata ssp. tuberosa) glades for a year-round food source, but also near extensive stands of Grey Alder (Alnus incana) which appear to be the beavers' preferred building material (they seem to select this over the various willows, which may be a preferred food source). The beaver also occasionally cut down youngish hemlock trees, apparently because they just don't like them!

The new activity by the young beavers in the Pulk Hole Brook wetland area also has an interesting side note as it is located at the confluence of a small rill that contains conspicuous iron bacteria that discolor the water that seeps into the wetland through the main dike that forms the Lake. There was an old iron sluice gate at that location which, though blocked up and no longer functional still probably emits iron into the seep water. I know that beaver need iron for their teeth, but can find no research to suggest that they might actually select a location such as this, so it may just be coincidental.

Summary of Current Research on Potamogeton Species in Lake Runnemede, 2021

There are three types of Potamogetons that currently live in Lake Runnemede: Hill’s Pondweed (Potamogeton hillii), Leafy Pondweed (Potamogeton foliosus) and a hybrid pondweed (Potamogeton zosteriformis X foliosus), which was formerly identified as Ogden’s Pondweed (Potamogeton x ogdenii).
The Paradise Park Commission established a dialogue with and hosted a visit by Dr. C. Barre Hellquist this summer regarding the health and welfare of the aquatic plants in Lake Runnemede. Dr. Hellquist is retired now but is considered one of the foremost experts in aquatic botany in the Northeast. It was his research that first identified the Ogden’s Pondweed in Lake Runnemede. During these discussions, Dr. Hellquist reported that recent research indicates that the plant in Lake Runnemede is not Ogden’s Pondweed, but instead a unique related hybrid found nowhere else in the world.

The taxonomy and systematics of the Pondweeds (Genus Potamogeton) has always been difficult. They exhibit a great deal of phenotypic plasticity (adaptation of a plant’s physical characteristics according to its environment) while adapting to their difficult aquatic habitats and some species rarely flower, preferring to reproduce vegetatively via rhizomes or winter buds. These adaptations also include genotypic variation (alterations to the plant’s genetic material) and exhibit a high degree of hybridization between species which has complicated the taxonomy even further.

One particular linear-leaved hybrid, Potamogeton x. longilingulatus, was identified during the 1930s, in various locations in the Northeast. During the 1980’s, Dr. Hellquist further classified this hybrid into two separate hybrids, Potamogeton ogdenii – a hybrid of P. zosteriformis X P. hillii, and Potamogeton haynesii – a hybrid of P. zosteriformis X P. strictifolius. P. ogdenii (Ogden’s Pondweed) was observed occasionally developing fruits, which led it to be reported as a new species, although it was actually a fertile hybrid. P. ogdenii and P. haynesii were distinct enough morphologically for the populations of each to be classified, including the population of P. ogdenii in Lake Runnemede.

Those classifications remained in place for 30+ years until the Czech botanist Zdenek Kaplan began working on developing a comprehensive treatment of the Genus worldwide. He refined DNA analysis techniques. In 2012, using plant materials provided by Dr. Hellquist, he determined that there were actually four hybrids with P. zosteriformis as the primary parent. Plants previously classified as P. ogdenii were further subdivided into three distinct hybrids, the original P. ogdenii, plus two unnamed hybrids: P. zosteriformis X P. berchtoldii and P. zosteriformis X P. foliosus. The first unnamed hybrid was determined to be the fertile hybrid previously described as P. ogdenii. The latter hybrid (the P. foliosus cross) was determined to be the plant in Lake Runnemede and it has not been identified in any other location worldwide.

The four P. zosteriformis hybrids are significant from an evolutionary biology perspective because they are aneuploid hybrids where the parent species have different numbers of chromosomes (P. zosteriformis has a chromosome number of 2n=28, while the other linear-leaved parents are 2n=26). The hybrids all have an intermediate chromosome number (2n=27) which makes them infertile. However, at some point in the distant past, early progenitors of the aquatic plants diverged into three separate genera within the family Potamogetonaceae apparently through modification of the chromosome numbers through a variety of mechanisms including aneuploidy. Through Dr. Kaplan’s research, we know that the diversity of speciation within the Potamogeton genus has also been presumably driven by aneuploidy and polyploidy. The exact mechanisms of how this evolution has been manifested are, as yet unknown. Thus, the significance of these hybrids, all of which have probably existed in their locations for centuries by reproducing vegetatively, can best be described as potentially containing the answers to questions that we don’t yet know how to ask.

Although one of the parents of the hybrid, P. foliosus, is widespread in Lake Runnemede, the other parent, P. zosteriformis, has never been found here. However, during the spring of 2021, I collected a floating specimen of P. zosteriformis in the wetland pond north of the western arm of the Lake. Since that wetland is separated from the Lake by a causeway and is upstream from the Lake itself, it is possible that the hybrid pre-dates the formation of the Lake during the 1860’s.

Hill’s Pondweed was first collected in Lake Runnemede in 1884 and has been found here sporadically ever since. It is quite similar to both P. foliosus and the hybrid, so it is possible that it is either missed (it really needs to be in fruit to positively be identified) or mis-identified. Either way, it is extremely rare in Lake Runnemede.

Several other Potamogeton species have been reported here at various times over the past century, including P. pusillus, P. strictifolius, P. perfoliatus, and P. natans. The first three are, like the current species, all linear-leaved and none are believed to be currently present. P. natans, which is a floating-leaved pondweed that is common in Vermont lakes and ponds, was noted here during the 1997 ANR survey, but has not been seen since. Many pondweeds are transported from lake to lake by waterfowl, but have a difficult time becoming established. The highly alkaline, hard waters of Lake Runnemede probably favor certain species of pondweeds over others.

The bottom line is that the plant formerly known as P. ogdenii, which is classified as a G1/SI critically imperiled species, is in fact an unnamed hybrid, found nowhere else in the world. However, none of this work is, as of yet, published. Dr. Kaplan’s research funding has been almost completely cut, and he has been moved to other projects within the Czech Academy of Sciences. Dr. Hellquist and his writing partner Garrett Crow are working on a revision to their two-volume Aquatic and Wetland Plants of Northeastern North America that will include the four hybrids, but it will probably be at least two years before that work is finished. In the interim, the Paradise Park Commission will continue to monitor and do our best to maintain the health of the plant and the Lake itself. We will continue to provide updates on the status of the hybrid and the Lake itself.

This information is extracted from our Paradise Park Management Plan (appendix G.), which can be found on the Town of Windsor website.

Spawn activity has been underway for about a week, but the warm-water species - Largemouth Bass and Sunfish, have been going full force and were extremely active today. Yellow Perch have probably finished spawning by now - I don't get visuals on Perch spawn much, but historically both Yellow Perch and Walleye are done spawning when the Black Locust comes into bloom, which has happened this week. Still no sign of Carp spawning, which is typically a bit later.

Snapping turtles are also reportedly doing their egg-laying adventures in the area now, but I still haven't seen any of our snappers sojourning.