Editing Eastern Prickly Pear (section)

=== West Rock Colonies (New Haven & Hamden) ===

There are three colonies of ''Opuntia humifusa'' found within the boundaries of West Rock Ridge State Park, which extends south to New Haven and north to Hamden.  The West Rock South Colony is located in the southern half of the park within New Haven.  The West Rock North Complex is comprised of two colonies which are located in the far-northern end of the state park.

==== Geographic & Historic Overview ====

West Rock Ridge is a prominent traprock ridge in Connecticut that runs in a north-south direction, extending roughly 5 miles from Hamden to northern New Haven and skirting the borders of Woodbridge and Bethany along its western edges.  Although West Rock Ridge is now almost entirely contained within the 1,800-acre West Rock Ridge State Park, this was not always the case.  West Rock Ridge, as a protected parcel of land, began in 1826 as a small 50-acre city park in New Haven (along the southern end of the ridge).  By 1975, the State of Connecticut had established West Rock Ridge State Park on areas of the ridge which were not owned by New Haven.  By 1982, New Haven's city park on West Rock Ridge had grown to encompass roughly 600 acres of land, all of which was donated to the state that year to be incorporated into West Rock Ridge State Park.  Further parcels of land were added to the state park whenever they became available, swelling the park grounds to the roughly 1,800 acres that it encompasses today.<ref name="historywestrock">"History of the Park." ''West Rock Ridge Park Association''. West Rock Ridge Park Association, n.d. Web. 7 May 2012. <http://westrockpark.wordpress.com/history/>.</ref>

==== Background Information ====

Although plenty of records exist which suggest the presence of ''Opuntia humifusa'' on West Rock Ridge, very few of these records offer any specific information as to where the cactus can actually be discovered.  This was of particular concern because West Rock Ridge State Park is over 5 miles long, extending from New Haven in the south to Hamden in the north (and even straddling the borders of Woodbridge and Bethany on its western edges).  Launching precisely targeted explorations of West Rock Ridge required the extensive study of satellite imagery, which permitted me to focus upon those areas which are not heavily forested and, thus, have at least some measure of potential to be ''O. humifusa'' habitat.

The oldest evidence that I've thus far discovered which attests to the existence of ''Opuntia humifusa'' in New Haven, Connecticut dates to the mid-1800s.  [[A Report on the Trees and Shrubs Growing Naturally in the Forests of Massachusetts, Volume 2]], published in 1846, very briefly mentions that the ''O. humifusa'' "is said to be found at New Haven, in Connecticut."<ref name="forestsmass">Emerson, George Barrell. ''A Report on the Trees and Shrubs Growing Naturally in the Forests of Massachusetts''. 2. Boston: Dutton and Wenworth, State Printers, 1846. 424. Print. <http://books.google.com/books/reader?id=7c4VAAAAYAAJ&printsec=frontcover&output=reader>.</ref>  No specific information is provided concerning the whereabouts of a colony.

In a modern written overview of West Rock Ridge in New Haven, Connecticut, the ''West Rock Ridge Park Association'' notes that the ridge offers an "extraordinary biodiversity of plants and animals from prickly pear cactuses to 230 species of birds".<ref name="aboutwestrock">"About West Rock." ''West Rock Ridge Park Association''. West Rock Ridge Park Association, n.d. Web. 19 Apr 2012. <http://westrockpark.wordpress.com/about/>.</ref>  The text does not offer any further mention of ''O. humifusa'', nor does it offer photographic evidence.

Further supporting this claim, an article was published on the website of the [http://msa2012.net Mycological Society of America] which details a group hike throughout West Rock Ridge scheduled to take place in 2012 during the organization's annual meeting.  Although the organisms of interest to mycologists are primarily mushrooms and other fungi, the article nonetheless states that hikers in the West Rock Ridge area "occasionally [find] prickly pear cactus".<ref name="myco2012">"Foray." ''Mycological Society of America 2012 Meeting''. Mycological Society of America, n.d. Web. 19 Apr 2012. <http://msa2012.net/schedule/fieldtrips.php>.</ref>  No further mention of cacti is made in this article.

The compelling evidence of the presence of ''O. humifusa'' on West Rock Ridge comes in the form of a photograph taken by Michael Hornak in 2011.  The image portrays ''O. humifusa'' in bloom and the geo-tag data pinpoints the location of the plant to be at the far northern end of West Rock Ridge State Park in Hamden, Connecticut.<ref name="hornak-photo">Hornak, Michael. ''Blooming on the Fourth''. 2011. Photograph. Flickr. Web. 1 May 2012. <http://www.flickr.com/photos/31522928@N08/5902419015/>.</ref>

==== Exploration ====

A preliminary examination of satellite imagery of West Rock Ridge revealed several areas along the southern end of the park where habitat suitable for ''O. humifusa'' potentially existed.  Because the southern end of the ridge has a greater concentration of areas that aren't covered with thick forest, my earliest exploration focused on this region.  Exploration of the northern end of the ridge was conducted later after the discovery of Hornak's ''O. humifusa'' photograph.

===== April 28, 2012 =====

I conducted a field exploration of the southern half of West Rock Ridge State Park on April 28, 2012, during which I carefully investigated all of the target areas in that region that were identified in my preliminary studies of satellite imagery.  This entailed a hike of approximately 3.08 miles and the route variously included hiking on foot trails and along the park road.  Extensive bush-whacking was required in order to explore all of the target locations, many of which were between 20 and 100 feet off of the road or established trails.

Target areas of exploration primarily included west-facing and south-facing ledges along the precipices of the southern half of West Rock Ridge.  Most of these areas were devoid of trees or, at least, very sparsely forested.  A thorough investigation of these target areas revealed no presence of ''Opuntia humifusa''.

However, I did succeed in locating a healthy colony of cacti in an area which was not within my original list of target areas.  The colony was located on a relatively small clearing within the forest towards the interior of the ridge.  This clearing consisted of an isolated, slightly elevated dome of exposed bedrock which enjoyed full sunlight and supported a bare minimum of herbaceous plants.  The colony included one large clonal cluster of cacti as well as a number of individual cacti along the outer perimeter of the clearing which were at various stages of maturation.

===== May 5, 2012 =====

A second field exploration was conducted on May 5, 2012 and involved an investigation of approximately 1.09 miles on the far northern extent of West Rock Ridge in Hamden, Connecticut.  This exploration revealed several areas, some quite large, where bedrock was exposed at the surface and there was a bare minimum of tree growth.  However, most of these "obvious" areas yielded no findings.  Eventually, I ventured to the steep, terraced precipices on the eastern side of the ridge and succeeded in discovering a large clonal colony of ''O. humifusa''.  I quickly noticed that this uppermost cluster was only the tip of the iceberg, as further clonal clusters could be seen growing on several lower ledges descending the face of the ridge.

After thoroughly documenting this colony, I began moving northwards and checking similar habitat for the presence of another colony.  I succeeded in discovering another colony approximately 200 feet further north of the first.  This colony shared a similar character with the nearby find, where a several clonal clusters could be found on successively lower-elevation ledges.

==== Status and Description ====

===== West Rock South Colony =====

[[File:West-rock-south-colony-opuntia.jpg|thumb|'''West Rock South Colony''', found on the southern half of West Rock Ridge in New Haven, CT]]My first field exploration identified a small, isolated, exposed patch of bedrock within the forest on the southern half of West Rock Ridge in New Haven, Connecticut upon which a colony of ''Opuntia humifusa'' currently lives.  I have not found any explicit evidence that the location of this colony has been previously documented.

The colony, which I have named '''West Rock South Colony''', consists of a large, clonal patch covering approximately 25 to 35 square feet.  Within 5 to 10 feet of this clonal center were approximately 6 or 7 individual outlying "satellite" cacti.

There is a bare minimum of herbaceous plants on the cacti habitat, as would be expected.  The most prominent additive feature of this colony is a large, gnarled, many-trunked juniper, specifically an Eastern Red Cedar (''Juniperus virginiana'' var. ''virginiana'').  The large clonal mass of cacti can be found tightly skirting the base of this tree.

===== West Rock North Complex =====

My second field exploration identified two very large colonies of ''Opuntia humifusa'' on the east-facing cliffs at the far northern end of West Rock Ridge in Hamden, Connecticut.  These colonies are situated barely 200 feet from each other and are rather significant inland colonies in Connecticut, primarily for their striking demonstration of circumstances in which ''O. humifusa'' can effectively expand its range via barochory (gravity) as opposed to zoochory (animal-assisted seed dispersal).  Although these two colonies were originally given separate names ('''West Rock Shepard Colony''' and '''West Rock Dunbar Colony'''), they were later collectively renamed the '''West Rock North Complex''' after changes to my naming conventions enacted in July 2012.

[[File:West-rock-dunbar-colony-opuntia.jpg|thumb|left|'''West Rock North Complex''', found on the northern end of West Rock Ridge in Hamden, CT]]Both of these colonies exhibit a structure which is supremely demonstrative of a scenario in which ''O. humifusa'' can successfully colonize surrounding habitat.  The uppermost clonal clusters of each colony are found at an elevation of roughly 500 feet.  Interestingly, numerous further clonal clusters can be found immediately below on successive terraced ledges that extend as far as 50 to 100 feet down the face of the ridge.  My observations suggest that the clonal clusters at the highest elevations are most likely the oldest, progenitor clusters and that, as cladodes and fruits broke free of these older plants, they would tumble down the face of the ridge.  Whenever these disconnected cladodes or fruits came to rest on a lower ledge, they would take root or germinate and produce a new clonal cluster.  Over a number of years then, these colonies became quite large and can be described as "cascading" down the face of the ridge.

I counted at least a dozen clonal clusters and as many as two dozen individual cacti in the southernmost of the two colonies.  The northernmost has fewer individual plants but its clonal clusters, of which I counted roughly ten, tended to be larger.  But the most impressive characteristic of this complex is the role which gravity has played in expanding the size of the colonies over time.  Both of these colonies probably began as a single, high-elevation clonal cluster on the uppermost ledges of West Rock Ridge.  With the help of gravity to carry broken cladodes and fruits to lower-elevation ridges, a process known as barochory, those two original colonies each expanded their mass by at least 1000%.  Indeed, the West Rock North Complex offers a rare demonstration of just how remarkably effective ''O. humifusa'' can be in expanding its local range without the assistance of animals as intermediaries, at least so long as the terrain is such that gravity can be harnessed to widely distribute fruits and broken cladodes.  No where else in Connecticut have I discovered a colony which clearly demonstrates the enormous potential of ''O. humifusa'' to harness barochory.

The West Rock North Complex was found in close association with Eastern Red Cedar (''Juniperus virginiana'' var. ''virginiana'') just as the considerably smaller West Rock South Colony.

==== Concerns About Preservation ====

The West Rock South Colony of ''Opuntia humifusa'' (identified on the southern half of West Rock Ridge) is apparently healthy but, as is typical of inland colonies, it is relatively small and confined to a single rocky outcrop.  Despite the fact that this colony is only about 60 feet off of the southern park road, it is unlikely that this colony is at risk of easy discovery.  There aren't any parking areas within close range to the colony, meaning that park traffic is not likely stop in the immediate vicinity.  In addition, there are no trails that lead to the rocky clearing, so hikers aren't likely to happen the colony.  Thus, there is a bare minimum of concern about the preservation of the ''O. humifusa'' colony at this site and a high probability that it will persist well into the future.

The colonies of the West Rock North Complex (identified on the northern end of West Rock Ridge) are exceptionally healthy and quite large.  Although hiking trails run within 40 or 50 feet of the clonal clusters at the highest elevations, the cacti would be difficult to spot unless one were expressly looking for them.  Furthermore, the "cascading" quality of these colonies means that, even if harm were to come to the more accessible high-elevation clonal clusters, those clusters on the lower ledges would still flourish by virtue of their relative inaccessibility.  There is little concern about the preservation of this ''O. humifusa'' complex.

==== Colony Locations and Statistics ====

===== West Rock South Colony =====

The West Rock South Colony is located in New Haven, Connecticut at West Rock Ridge State Park.  The coordinates of the colony within the park are 41.335736° , -72.964300°.

<ul>
<li>To view this location in Google Maps, [http://maps.google.com/?q=41.335736,%20-72.964300 click here].</li>
<li>To download the GPS tracklog of this exploration (KML  format), [[Media:West-Rock-Ridge-State-Park-South-Prickly-Pear-Cactus.kml|click here]].</li>
</ul>

Pertinent statistics concerning the location include:

<ul>
<li>'''Elevation of Colony:''' ~429 feet above sea level</li>
<li>'''Surficial Geology:''' Unknown (likely Basalt)</li>
<li>'''Habitat Type:''' Inland Cliffs/Mountain Peaks <ref name="habitat-types">Habitat type is categorized using the Habitats Classification Scheme (Version 3.0) defined by the ''International Union for Conservation of Nature and Natural Resources''. <http://www.iucnredlist.org/technical-documents/classification-schemes/habitats-classification-scheme-ver3>.</ref>
</li>
</ul>

===== West Rock North Complex =====

The West Rock North Complex, comprised of two distinct colonies, is located in Hamden, Connecticut at West Rock Ridge State Park.  The coordinates of the southernmost colony are 41.398765° , -72.945621°, while the coordinates of the northernmost colony are 41.398970°, -72.944514°.

<ul>
<li>To view the location of the southernmost colony in Google Maps, [http://maps.google.com/?q=41.398765,%20-72.945621 click here].</li>
<li>To view the location of the northernmost colony in  Google Maps, [http://maps.google.com/?q=41.398970,%20-72.944514 click here].</li>
</ul>

Pertinent statistics concerning the location of the complex include:

<ul>
<li>'''Elevation of Colony:''' Ranges from ~508 feet to ~430 feet above sea level</li>
<li>'''Surficial Geology:''' Basalt</li>
<li>'''Habitat Type:''' Inland Cliffs/Mountain Peaks <ref name="habitat-types">Habitat type is categorized using the Habitats Classification Scheme (Version 3.0) defined by the ''International Union for Conservation of Nature and Natural Resources''. <http://www.iucnredlist.org/technical-documents/classification-schemes/habitats-classification-scheme-ver3>.</ref>
</li>
</ul>