Site Preparation Drives Long-Term Plant Community Dynamics in Restored Tallgrass Prairie: A Case Study in Southeastern South Dakota.

Most tallgrass prairies have been destroyed or altered, making restoration an important component to their conservation. Our goal was to evaluate progress 12-years post-restoration at Spirit Mound Historic Prairie and determine whether the outcomes varied based on different land use and restoration histories across the site. We examined changes in plant diversity, richness, evenness, non-native species relative abundance, and community composition from 2004 to 2013. Areas with different restoration treatments and land-use histories showed divergent results. Seventy percent of the site, previously annual row crop, was reconstructed using herbicide application followed by native seeding (hereafter reconstruction). Areas that were previously grazed, 15 % of the site, were restored with only partial seeding and no herbicide treatment (hereafter rehabilitation). Species richness and diversity increased over 40 % in the reconstruction since 2004 and remained over 1.9 times higher in the reconstructed areas than rehabilitated areas. Diversity did not change in the rehabilitation, but richness increased 47 % since 2004. Evenness decreased 11-26 % over time in both areas. Non-native species relative abundance did not change from 2004 to 2013, and remained five times higher in the rehabilitation than the reconstruction. Native C4 grass and forb abundance increased over time in the reconstruction, whereas non-native C3 grasses remained dominant in the rehabilitation. These results showed that restoration outcomes were radically different 12-years post-restoration among areas with different prior land uses that were subjected to different restoration practices. Long-term assessments are important to accurately determine restoration progress and inform management decisions.

Refinement of the modified-relative-dose-response test as a method for assessing vitamin A status in a field setting: experience with Indonesian children.

The modified-relative-dose-response (MRDR) test, which has been used extensively throughout the world for assessing vitamin A status, has been simplified. The major methodologic change resulting from the current studies in Indonesia is the use of graded standard doses of 3,4-didehydroretinyl acetate (DRA) based on the age range of the population of interest. Instead of a dose of 0.35 mumol/kg body wt, standard doses of 5.3 mumol for children younger than 6 y, 7.0 mumol for children between 6 and 12 y of age, and 8.8 mumol for adults and children > 12 y of age are suggested for field use. The acceptable time between administering the oral dose and obtaining a blood sample was validated as being 4-7 h in a group of children (n = 84) by taking two blood samples per child between 3 and 7 h after dosing with DRA. Furthermore, DRA in vitamin E-containing corn oil, with or without the addition of 4.6 mmol all-rac-alpha-tocopheryl acetate/L, was found to be stable for > or = 18 mo at 2 degrees C and at -20 degrees C, but not at 22 degrees C or at 37 degrees C. When DRA was stored in amber glass vials, stability was affected more by temperature than by exposure to room light. In keeping with earlier studies in adults, the ratio of 3,4-didehydro-retinol to retino tends to be independent of body weight. Indeed, slower growing children (ie, those with lower weight-for-age) may have a somewhat better vitamin A status than their heavier counterparts.

Vitamin A status of Indonesian children infected with Ascaris lumbricoides after dosing with vitamin A supplements and albendazole.

In developing countries, both marginal vitamin A status and intestinal helminths are common among children. Indonesian children (n = 309, 0.6-6.6 y), known to be infected with Ascaris lumbricoides, were randomized into six different treatment groups (A-F). The treatments included 210 mumol vitamin A supplement and a dose of 400 mg albendazole (5-propylthio-1H-benzimidazol-2-yl carbamic acid methyl ester) administered orally either at the same health visit (Groups B and F) or at different contact times during a 1-mo period (groups A, C, D and E). Vitamin A status was assessed both before and 3-4 wk after the treatments by the modified relative dose response (MRDR) test. Vitamin A supplementation was most important in improving the vitamin A status (P < 0.0001) of these children, whereas treatment for ascariasis alone (P = 0.370) and the statistical interaction between treatment for ascariasis and vitamin A (P = 0.752) were not. Serum retinol concentrations marginally improved (P = 0.051) in two of the groups that received vitamin A and albendazole but not in the third group that received vitamin A only. The MRDR test proved a better discriminator of the effects of these treatments on vitamin A status than changes in serum retinol concentrations.

Comparison of vitamin A status assessment techniques in children from two Indonesian villages.

The vitamin A statuses of preschool-aged children without clinical eye signs of vitamin A deficiency in two villages near Bogor, West Java, Indonesia, were studied by the modified-relative-dose-response (MRDR) test and the conjunctival impression cytology (CIC) method. In the second village the relative-dose-response (RDR) test was also applied. Of the children examined, 71% in the first village (group 1, n = 75) and 36% in the second village (group 2, n = 83) fell below the third percentile of the WHO reference standard of weight-for-age. The following provisional cutoff values for inadequate vitamin A status in Indonesia were used: MRDR (> or = 0.06), RDR (> or = 20%), CIC (an abnormal impression in one eye). The percent abnormal values were as follows: group 1--MRDR 48%, CIC 51%; group 2--MRDR 12%, RDR 11%, CIC 5%. Thus, the indicators gave concordant results for the two populations but did not necessarily identify the same individuals at risk. The consistency of the RDR test was much improved by increasing the oral dose of 3.5 mumol and by retesting only after a 3-wk interval.