1. Evaluating climate effects on plant-soil interactions in terrestrial ecosystems remains challenging due to the fact that floristic composition co-varies with climate, particularly along rainfall gradients. It is difficult to separate effects of precipitation per se from those mediated indirectly

Light foraging by trees is a fundamental process shaping forest communities. In heterogeneous light environments this behavior is expressed as plasticity of tree growth and the development of structural asymmetries. We studied the relative influence of neighborhood structure and directional solar ra

Map data used in simulations described in: Mifuyu Nakajima and Carol l. Boggs. 2015. Fine-grained distribution of a non-native resource can alter the population dynamics of a native consumer. PLOS ONE.

Delphinium nelsonii Greene (Ranunculaceae) individuals which were watered produced significantly more nectar per flower than did control individuals. The watered plants also set significantly more seeds per flower than did the controls. Hand pollinations suggest that the seed set difference was due

The fact that residual nectar exists is consistent with predictions of optimal foraging theory but more detailed work is necessary before it can be concluded that the volumes left behind in A. columbianum flowers are optimal.

Evidence is presented that discrimination occurs because white flowers have inferior ‘nectar guides’ and therefore require longer handling times than blue flowers, and pollinators may experience lower net rates of energy intake on white flowers, a sufficient reason for undervisitation by optimally-f

ABSTRACT Demographically oriented sampling in the wild and biochemical study of allozymes in the laboratory have been used to probe maintenance of the phosphoglucose isomerase polymorphism of Colias butterflies.—The several alleles at this locus show negative or no covariation among their frequencie

The hypothesis that a sychrony of the time of seed dispersal and the period when most ants (mutualists) and least rodents (predators) are active would be advantageous to the plant species is discussed.

-Field tests quantifying the behavioral responses of ants to the seeds of twenty Rocky Mountain species were conducted in Gunnison County, Colorado. The results indicate that Claytonia lanceolata Pursh, Corydalis aurea Willd., C. caseana A. Gray., Delphinium nelsoni Greene, and Viola nuttallii Pursh

Females tended to specialize upon one or two species, at least in the short term, and the pattern of oligophagy for the population as a whole is partly generated by variation in the host-seeking behavior of individual females.

Reproduction in a population of marked pikas (Ochotonaprinceps) was observed over a 3-year period in the Rocky Mountains of Colorado. Pikas were seasonally polyestrous; all adult females initiated two litters each summer. However, most females (24 of 25) weaned only a single litter. The number of su

Relative tendencies toward dispersal or philopatry in a marked population of alpine mammals, the pika (Ochotona princeps), were investigated over a 3-year period in the Rocky Mountains of Colorado to help understand their low intrapopulation genetic variability.

Colorado Energy Research Institute. February 12, 1975. ?

Thorne Ecological Institute. March 1, 1975.

Ralph E. Clark III and Albert G. Melcher. Colorado Energy Research Institute. October 1975.

Colorado Humanities Program. Colorado Humanities Program/ U of Colorado. 1975.