Climate Trajectories for Colorado's Terrestrial Ecosystems

By Karin Decker, CNHP Ecologist

Recently we blogged about CNHP’s Conservation Planning Team evaluating the potential effects of future climate conditions on Colorado’s species and ecosystems. An important part of this work is to look at projected future conditions in comparison with recent climate patterns. The graph below shows the projected direction of change in the current location of Colorado’s major terrestrial ecosystems as described by average annual temperature and precipitation.

Projected seasonal average precipitation and mean temperature trajectories for current upland ecosystem ranges in Colorado summer by mid-century under a high radiative forcing scenario (RCP8.5).

A comparison of recent average values of climate variables with projected values for the current locations of these ecosystems in Colorado show shows seasonal differences both in the direction and amount of projected changes in temperature and precipitation. For instance, ecosystems of higher elevations (e.g., alpine tundra and spruce-fir forest) are projected to experience a greater increase in winter precipitation than those of lower elevations (e.g. sandsage and shortgrass prairie), although the amount of warming is similar for all elevations. Projected changes in summer precipitation are generally less than for winter, with some ecosystems seeing a slight increase and others a slight decrease.

Of course average temperature and precipitation patterns are not the whole story. The interaction of climatic conditions with other abiotic factors (e.g. soils, disturbance), life-history traits of the component species (e.g. growth form, dispersal mechanisms), and past history shapes the observed distribution of ecosystems. Because many of the characteristic species of these ecosystems are long-lived, the time lag between the onset of new climate conditions and the response of the species to those conditions, adds another level of uncertainty to projections of future distribution. Climate changes over the past few decades are probably already facilitating a gradual modification of ecosystem extent and species composition that will become more apparent by mid-century.

CNHP Pilots Water Chemistry Measurements in Wetland Condition Assessments

By Laurie Gilligan, CNHP Wetland Ecologist

The wetlands team kicked off their water chemistry data collection pilot project in the Lower Arkansas Basin under perfect weather conditions: rain, lightning, mud, and more rain! All of the spring rain has filled playas that have not been saturated in years, and is greening up the Arkansas River floodplain and its marshes. These conditions will give our crew the opportunity to test how well our data collection methods work in waters with high variability in sediment and water levels. However, accessing sites safely has meant dodging the notoriously fierce thunderstorms that roll over the open southeastern plains.

Joanna Lemly, CNHP wetland ecologist, collects water samples
in a playa on the southeastern plains of Colorado.

Pools within a small stream outside Florence, Colorado provide
good habitat for native plains fish species.

CNHP is excited to add water chemistry measurements to this year’s wetland assessments. While water chemistry measurements are frequently taken in lakes and rivers, more research is needed on nutrient levels, metal loads, and other water chemistry measurements in shallow vegetated wetlands. By adding water chemistry measurements to our wetland condition assessments, we can begin to observe the relationships between the wetland’s water chemistry and its overall condition. The first step with this pilot year of water quality sampling is to refine protocols and analysis, and to get a glimpse of the range of variation in water chemistry parameters that we may see in the plains.

Playa on Bureau of Land Management (BLM) land in Huerfano County, Colorado. With extra spring moisture in 2015, many playas in the Lower Arkansas Basin showed concentric rings of vegetation-in this case, an inner ring of spreading yellowcress (Rorripa sinuata).

New Graham's Beardtongue Population Found

During a recent rare plant survey funded by the U.S. Fish and Wildlife Service, CNHP botanist/ecologist Delia Malone discovered a new population of Graham's beardtongue (Penstemon grahamii) south of Rangely, Colorado. This rare plant is known from only six other occurrences in the state of Colorado. Graham's beardtongue is found on raw shale slopes and knolls of the Green River Formation in Rio Blanco County, Colorado, as well as three counties in eastern Utah: Carbon, Duchesne, and Uintah.

The bright white and caramel-colored shales of the Green River Formation, which often look like pieces of broken plates, give rise to highly basic soils. These soils support a very unique plant community dominated by dwarf shrubs like spiny greasebush (Glossopetalon spinescens) and shadcale saltbush (Atriplex confertifolia). Forbs species such as dragon milkvetch (Astragalus lutosus) and ephedra buckwheat (Eriogonum ephedroides) are also commonly found growing on Green River shales in occupied Graham's beardtongue habitat. This species is considered Sensitive by the BLM.  

Lured in by the bright yellow, protruding staminode called a beardtongue, a Pseudomasaris wasp lands inside the corolla of a rare Graham's beardtongue outside of Rangely, Colorado.

  

Climate Space: Looking Towards the Future

By Karin Decker

The Conservation Planning Team at CNHP works on a number of projects that evaluate the potential effects of future climate conditions on Colorado’s species and ecosystems. As part of this work, we need to know what current climate conditions are. Here’s a look at the current “bioclimatic envelope” for Colorado’s major terrestrial ecosystems as described by average annual temperature and precipitation.

Bioclimatic envelope as represented by annual precipitation and mean temperature for ecosystems in Colorado. Error bars represent the 10-90% range around the mean.

Desert shrubland occupies the driest bioclimatic envelope, while sandsage and shortgrass prairie are the warmest. Statewide, ponderosa pine forest, oak-shrubland and sagebrush shrubland are closely related in bioclimatic space, and show substantial overlap with the warmer and drier pinyon-juniper woodlands and semi-desert grassland. Above these warm and dry types, mixed conifer, aspen, and lodgepole forest share a mid-elevation envelope with montane grasslands. The coldest, wettest environments are occupied by alpine types, with spruce-fir forest nearby in bioclimatic space.

Although a warmer future appears certain, everything else is much more complicated!