1. Hypothesis:
There are no serious or systemic negative effects on Open Space due to recreation (including off-leash dogs).
Good Evening Council,
As the saying goes, the buck stops here. Although you do not run the day-to-day operations of Open Space and Mountain Parks you are the ultimate responsible decision makers. The Visitor Management Plan that you are reviewing extends that responsibility well beyond your tenure, and well beyond the lives of those who have voted for or against you. This is a tremendous burden because although Open Space is at risk from degradation on a daily basis, it is still a jewel at the junction between mountains and plains.
My purpose tonight is to give you a bit of a foundation for rejecting the hypothesis that “there are no serious or systemic negative effects on Open space due to recreation”. If you really understand science, you understand that science can prove nothing, but it can reject bad ideas.

2. Why? Lack of awareness is sometimes substituted for facts.
Daily Camera Editorial – Dec. 5, 2004
Although the hypothesis is absurd to many, there are others who still profess it.
The Daily Camera Editorial for example that has stated, “We’ve seen no data demonstrating serious, systemic damage to open space lands.”

3. Others have stated that a problem doesn’t really exist and for that reason there is no justification for restrictions.

4. Lack of awareness is also used as a basis for demands.
This lack of awareness is also used as a basis for demands. Mike Fontenot for example has stated that after 34 years, he is certain that his presence has never had any negative impact on the environment.

5. Recreational Impacts Include, but are not limited to:
Wildlife harassment, mortality and habitat fragmentation,
Accelerated erosion and water quality degradation,
Weed introduction and distribution.
The literature is filled with examples of recreational impacts. To bring the issue home I will focus on the Weed issue.

6. What are the state listed noxious weeds?
African rue (Peganum harmala)
Camelthorn (Alhagi pseudalhagi)
Common crupina (Crupina vulgaris)
Cypress spurge (Euphorbia cyparissias)
Dyer's woad (Isatis tinctoria)
Giant salvinia (Salvinia molesta)
Hydrilla (Hydrilla verticillata)
Meadow knapweed (Centaurea pratensis)
Mediterranean sage (Salvia aethiopis)
Medusahead (Taeniatherum caput-medusae)
Myrtle spurge (Euphorbia myrsinites)
Purple loosestrife (Lythrum salicaria)
Rush skeletonweed (Chondrilla juncea)
Sericea lespedeza (Lespedeza cuneata)
Squarrose knapweed (Centaurea virgata)
Tansy ragwort (Senecio jacobaea)
Yellow starthistle (Centaurea solstitialis)
Absinth wormwood (Artemisia absinthium)
Black henbane (Hyoscyamus niger)
Bouncingbet (Saponaria officinalis)
Bull thistle (Cirsium vulgare)
Canada thistle (Cirsium arvense)
Chinese clematis (Clematis orientalis)
Common tansy (Tanacetum vulgare)
Common teasel (Dipsacus fullonum)
Corn chamomile (Anthemis arvensis)
Cutleaf teasel (Dipsacus laciniatus)
Dalmatian toadflax, broad-leaved (Linaria dalmatica)
Dalmatian toadflax, narrow-leaved (Linaria genistifolia)
Dame's rocket (Hesperis matronalis)
Diffuse knapweed (Centaurea diffusa)
Eurasian watermilfoil (Myriophyllum spicatum)
Hoary cress (Cardaria draba)
Houndstongue (Cynoglossum officinale)
Leafy spurge (Euphorbia esula)
Mayweed chamomile (Anthemis cotula)
Moth mullein (Verbascum blattaria)
Musk thistle (Carduus nutans)
Orange hawkweed (Hieracium aurantiacum)
Oxeye daisy (Chrysanthemum leucanthemum)
Perennial pepperweed (Lepidium latifolium)
Plumeless thistle (Carduus acanthoides)
Quackgrass (Elytrigia repens)
Redstem filaree (Erodium cicutarium)
Russian knapweed (Acroptilon repens)
Russian-olive (Elaeagnus angustifolia)
Salt cedar (Tamarix chinensis, T.parviflora, and T. ramosissima)
Scentless chamomile (Matricaria perforata)
Scotch thistle (Onopordum acanthium)
Scotch thistle (Onopordum tauricum)
Spotted knapweed (Centaurea maculosa)
Spurred anoda (Anoda cristata)
Sulfur cinquefoil (Potentilla recta)
Venice mallow (Hibiscus trionum)
Wild caraway (Carum carvi)
Yellow nutsedge (Cyperus esculentus)
Yellow toadflax (Linaria vulgaris)
Chicory (Cichorium intybus)
Common burdock (Arctium minus)
Common mullein (Verbascum thapsus)
Common St. Johnswort (Hypericum perforatum)
Downy brome (Bromus tectorum)
Field bindweed (Convolvulus arvensis)
Halogeton (Halogeton glomeratus)
Johnsongrass (Sorghum halepense)
Jointed goatgrass (Aegilops cylindrica)
Perennial sowthistle (Sonchus arvensis)
Poison hemlock (Conium maculatum)
Puncturevine (Tribulus terrestris)
Velvetleaf (Abutilon theophrasti)
Wild proso millet (Panicum miliaceum)
This is the list of state listed noxious weeds. I have asked OSMP to provide the following maps focusing on two species, diffuse knapweed and jointed Goatgrass. The data collected to prepare these maps has been limited by both budget and time. So you must understand that not all weed species or weed locations have been mapped. But just based on the data that exist lets see if the hypothesis seems to hold up in just a few examples.

7. Here is an overview of the areas that were mapped for knapweed from 1993 to OSMP is in light green, knapweed areas are light brown and trails are red. Although in 2000 these areas were mostly peripheral to the mountain trails, lets zoom in to the southern area near Flatiron Vista trail.

8. 93
Flatirons Vista
This figure shows the areas mapped for knapweed five years ago. It is easy to see that the knapweed occurs both along the Flatirons Vista trail and in scattered patches outside of the official trail system. There are many possible reasons why the knapweed was so closely aligned with the trail such as, people, horses, dogs, OSMP service vehicles, and others. It is not possible to prove what was the cause, but this high level of correlation between trail and weed distribution suggests that there is a link. Common sense may be used to reject a faulty hypothesis when exceptions to the hypotheses are observed repeatedly.
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9. This is not a map of weed species per-se, but rather a mapping of the treatment locations for a variety of weeds for the last two years. Does this seem non-systemic or non-serious to you? Let’s zoom in to the area I know best and have watched closely for over 15 years. Sanitas Valley.

10. Wonderland Lake
Goatgrass in the spring.
Bare ground - dog trails.
This is a map that includes Goatgrass treatment for 2003 and 2004 in the Sanitas and Wonderland Lake areas. Goatgrass is an aggressive annual grass that greens up early in the spring, dries out rapidly and becomes a fire hazard as well as a habitat destroyer.
Notice the close correlation with trails and hang gliding access routes. It has expanded rapidly in the last 5 years. I first observed Goatgrass in Sanitas about 5 years ago and its distribution was very limited. It eventually dominated the large fill area at the base of Sanitas that was previously well vegetated but trampled to bare ground by dogs. It expanded rapidly in the bare soil both at the trailhead and on the margins of the trails. The seed is not wind born, but rather has awns or hairs and a sticky back that are just sticky enough to attach and detach to people and dogs.
Sanitas

11. Hypothesis:
There are no serious or systemic negative effects on Open Space due to recreation (including off-leash dogs).
My purpose tonight was to give you a bit of a foundation for rejecting the following hypothesis. Although science can prove nothing I hope that simple awareness, some real data, and your own observations can help you reject this faulty hypothesis.