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Allocation of resources to reproduction in Styrax obassia in a masting year.

ABSTRACT: An analysis is presented of three possible pathways of reproductive allocation, namely, allocation of resources to reproductive organs from reproductive shoots, from non-reproductive shoots and from the main trunk. These pathways were examined by comparing the amount of storage starch in reproductive shoots, non-reproductive shoots and the main trunk in Styrax obassia, a typical masting tree species, during a year of little flowering (1999) and in a mass-flowering year (2000). In addition, we measured rates of light-saturated photosynthesis in leaves of reproductive and non-reproductive shoots to examine the contribution of photosynthetic production to reproductive costs. In both the main trunk and non-reproductive shoots the pattern of seasonal variation in the amount of starch did not differ between 1999 and 2000. However, in the mass-flowering year, the amount of starch in the reproductive shoots was less than that in non-reproductive shoots during the growing season. Thus, reproductive shoots bore most of the cost of reproduction, although non-reproductive shoots and the main trunk also bore some of the cost. Mass-based rates of light-saturated photosynthesis of the leaves of reproductive shoots were significantly higher than those of non-reproductive shoots during both the flowering and the fruiting period. However, leaves of reproductive shoots had a significantly smaller area, a lower mass per area, and lower concentrations of nitrogen than leaves of non-reproductive shoots, although the number of leaves did not differ between the two types of shoots. Therefore, the amount of photosynthate per shoot was significantly lower in reproductive shoots than in non-reproductive shoots. These results suggest that the cost of reproduction depends predominantly on storage starch in reproductive shoots, although it is still unclear how much photosynthate is allocated to reproductive organs from non-reproductive shoots.

SUBMITTER: Miyazaki Y

PROVIDER: S-EPMC4233828 | biostudies-literature | 2002 Jun

REPOSITORIES: biostudies-literature

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Allocation of resources to reproduction in Styrax obassia in a masting year.

Miyazaki Yuko Y Hiura Tsutom T Kato Etsushi E Funada Ryo R

Annals of botany 20020601 6

An analysis is presented of three possible pathways of reproductive allocation, namely, allocation of resources to reproductive organs from reproductive shoots, from non-reproductive shoots and from the main trunk. These pathways were examined by comparing the amount of storage starch in reproductive shoots, non-reproductive shoots and the main trunk in Styrax obassia, a typical masting tree species, during a year of little flowering (1999) and in a mass-flowering year (2000). In addition, we me ...[more]

PMID: 12102532

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Project description:BACKGROUND:Health resources are limited, which means spending should be focused on the people, places and programs that matter most. Choosing the mix of programs to maximize a health outcome is termed allocative efficiency. Here, we extend the methodology of allocative efficiency to answer the question of how resources should be distributed among different geographic regions. METHODS:We describe a novel geographical optimization algorithm, which has been implemented as an extension to the Optima HIV model. This algorithm identifies an optimal funding of services and programs across regions, such as multiple countries or multiple districts within a country. The algorithm consists of three steps: (1) calibrating the model to each region, (2) determining the optimal allocation for each region across a range of different budget levels, and (3) finding the budget level in each region that minimizes the outcome (such as reducing new HIV infections and/or HIV-related deaths), subject to the constraint of fixed total budget across all regions. As a case study, we applied this method to determine an illustrative allocation of HIV program funding across three representative oblasts (regions) in Ukraine (Mykolayiv, Poltava, and Zhytomyr) to minimize the number of new HIV infections. RESULTS:Geographical optimization was found to identify solutions with better outcomes than would be possible by considering region-specific allocations alone. In the case of Ukraine, prior to optimization (i.e. with status quo spending), a total of 244,000 HIV-related disability-adjusted life years (DALYs) were estimated to occur from 2016 to 2030 across the three oblasts. With optimization within (but not between) oblasts, this was estimated to be reduced to 181,000. With geographical optimization (i.e., allowing reallocation of funds between oblasts), this was estimated to be further reduced to 173,000. CONCLUSIONS:With the increasing availability of region- and even facility-level data, geographical optimization is likely to play an increasingly important role in health economic decision making. Although the largest gains are typically due to reallocating resources to the most effective interventions, especially treatment, further gains can be achieved by optimally reallocating resources between regions. Finally, the methods described here are not restricted to geographical optimization, and can be applied to other problems where competing resources need to be allocated with constraints, such as between diseases.

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Allocation of resources to reproduction in Styrax obassia in a masting year.

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Allocation of resources to reproduction in Styrax obassia in a masting year.

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