Climate Change Impacts on the Future Distribution of Date Palms: A Modeling Exercise Using CLIMEX

Climate is changing and, as a consequence, some areas that are climatically suitable for date palm (Phoenix dactylifera L.) cultivation at the present time will become unsuitable in the future. In contrast, some areas that are unsuitable under the current climate will become suitable in the future. Consequently, countries that are dependent on date fruit export will experience economic decline, while other countries’ economies could improve. Knowledge of the likely potential distribution of this economically important crop under current and future climate scenarios will be useful in planning better strategies to manage such issues. This study used CLIMEX to estimate potential date palm distribution under current and future climate models by using one emission scenario (A2) with two different global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR). The results indicate that in North Africa, many areas with a suitable climate for this species are projected to become climatically unsuitable by 2100. In North and South America, locations such as south-eastern Bolivia and northern Venezuela will become climatically more suitable. By 2070, Saudi Arabia, Iraq and western Iran are projected to have a reduction in climate suitability. The results indicate that cold and dry stresses will play an important role in date palm distribution in the future. These results can inform strategic planning by government and agricultural organizations by identifying new areas in which to cultivate this economically important crop in the future and those areas that will need greater attention due to becoming marginal regions for continued date palm cultivation.     

Distribution of aboveground live biomass in the Amazon basin

The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land‐cover and land‐use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site‐specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old‐growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300 Mg ha⁻¹ here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300 Mg ha⁻¹. Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200 Mg ha⁻¹. The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and belowground biomass, is 86 Pg C with ±20% uncertainty.     

Case studies and mathematical models of ecological speciation. 2. Palms on an oceanic island

A recent study of a pair of sympatric species of palms on the Lord Howe Island is viewed as providing probably one of the most convincing examples of sympatric speciation to date. Here we describe and study a stochastic, individual-based, explicit genetic model tailored for this palms system. Overall, our results show that relatively rapid (<50,000 generations) colonization of a new ecological niche, and sympatric or parapatric speciation via local adaptation and divergence in flowering periods are theoretically plausible if (i) the number of loci controlling the ecological and flowering period traits is small; (ii) the strength of selection for local adaptation is intermediate; and (iii) an acceleration of flowering by a direct environmental effect associated with the new ecological niche is present. We discuss patterns and time-scales of ecological speciation identified by our model, and we highlight important parameters and features that need to be studied empirically in order to provide information that can be used to improve the biological realism and power of mathematical models of ecological speciation.     

Microsatellite Analysis of Oil Palms and their Progenies Bred in Papua New Guinea

Our aim was to assess parental and population genetic variability in a partially nested set of breeding populations from the breeding program at Dami Research Station (West New Britain, PNG). Twenty microsatellite markers were tested for their ability to characterize genetic variation in oil palm populations bred at Dami Research Station. One hundred and twenty six individuals, including 100 F₁ tenera hybrids of Dami Deli crossed with either AVROS, Ghana or AVROS/Ghana breeding lines were analysed. Eighteen of these markers were polymorphic within and among populations, amplifying 103 alleles in oil palm. Three individuals of other palm species (Cocos nucifera and two Phoenix spp.) were included as outliers. With these markers we have the power to distinguish individual palms, hence we conclude that they will facilitate association of markers with important phenotypic traits to streamline future breeding and selection.     

中国象牙参属植物的分布及药用资源

目的:研究中国象牙参属植物种类分布及药用资源,探讨它们的分布特点及其药用价值.方法:通过野外调查,标本采集鉴定,馆藏植物标本的查阅和文献资料的整理进行研究.鲒果:中国象牙参属植物有14种3变种,其中有8种作为藏药和民间草药使用,具有补肺定喘,治咳嗽哮喘或温中散寒、止痛消食等功效等功效.结论:我国西南地区象牙参属药用植物资源丰富,值得进一步开发利用.     

Ammonium and phosphate regenerationby the zooplankton of an Amazon floodplain lake

SUMMARY. 1. Regeneration of ammonium and phosphate by macro-zooplankton (Cladocera. adult copepods. and copepodites) was measured in Lake Calado. an Amazon floodplain lake, Macrozooplanktonabundances ranged between 1×10⁴ and 3×10⁵ individuals m⁻².
2. Phosphate regeneration ranged from 0.2 to 1.3 μ mol PO₄ m⁻² b⁻¹at station 1. located 2 km from the Solimoes River, and from 1.6 to8.3 μ mol PO₄ m⁻² h ⁻¹ at station 3, located 7 km from the SolimoesRiver. Ammonium regeneration at stations 1 and 3 ranged from 1.7 to11.9 and from 13.4 to 77.2 μ mol NH₄ m⁻² h⁻¹. respectively.
3. Zooplankton regenerated ammonium and phosphate at similarrates during rising and falling waier. Regeneration by macrozooplankton was low compared to other tropical lakes and compared to microbesand microzooplankton in Lake Calado.     

Distribution of beta-thalassemia mutations in south China and their association with haplotypes.

DNA from 93 Chinese beta-thalassemia chromosomes were hybridized to eight different mutant oligomers to determine their specific mutation. Four mutations accounted for 87% of the chromosomes; in descending frequencies, these mutations were codon 41/42, IVS-2 nt654, codon 17, and -28. Since codon 41/42 mutation can be associated with multiple beta-thalassemia haplotypes, codon 41/42 is probably a hot spot for the 4-bp deletion. The distributions of these mutations were mapped to various regions in south China. These data are useful for the planning of prenatal diagnosis programs in other Chinese communities worldwide.