Nonstructural carbohydrate and element pools in globemallow ( Sphaeralcea ): defoliation effects and seasonal trends

Globemallows ( Sphaeralcea spp.) are arid land forbs suitable for seeding with crested wheatgrass ( Agropyron cristatum [L.] Geartner). However, little is known about the quantitative role of total nonstructural carbohydrates (TNC) in relation to globemallow tolerance of grazing, or about seasonal dynamics of mineral elements. The objectives of this study were to compare TNC and element pools (concentration x biomass) in the roots, crowns, and shoots of clipped versus unclipped S. munroana (Dogl.) Spach. Seedlings of S. munroana were transplanted to a northern Utah field site in 1985. Interplanted crested wheatgrass provided uniform competitive background. One-half of the globemallows were clipped to 5 cm on 10 May 1986 when stems were elongating the root and crown TNC pools were low. The remaining globemallows were not clipped. Root, crown and shoot pools of TNC and elements (N, P, K, Ca, and MG) were determined on 1 May, 20 May, 7 June, 11 July, 22 September, and 5 November 1986, and 29 May 1987. Defoliation did not affect shoot weights during a 1-year period. Experiment-long TNC and element pools also were not affected by clipping. Results indicate that S. munroana shoot recovery from a single spring grazing during a 1-year period would not be impaired by low root and crown TNC pools, and that TNC stored in the roots and crowns would account for only 7% of the regrowth produced. Furthermore, TNC and element pools of roots and crowns were generally constant from May to September but increased from September to November. TNC and element pools in shoots increased from May to September and then generally declined by November. TNC Pools of roots and crowns declined during winter.     

Kuhn vs. Popper on criticism and dogmatism in science: a resolution at the group level

Popper repeatedly emphasised the significance of a critical attitude, and a related critical method, for scientists. Kuhn, however, thought that unquestioning adherence to the theories of the day is proper; at least for ‘normal scientists’. In short, the former thought that dominant theories should be attacked, whereas the latter thought that they should be developed and defended (for the vast majority of the time).Both seem to have missed a trick, however, due to their apparent insistence that each individual scientist should fulfil similar functions (at any given point in time). The trick is to consider science at the group level; and doing so shows how puzzle solving and ‘offensive’ critical activity can simultaneously have a legitimate place in science. This analysis shifts the focus of the debate. The crucial question becomes ‘How should the balance between functions be struck?’