Dataset Information

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands.

ABSTRACT: In the Horn of Africa, little is known about temporal changes in hydroclimate owing to the influence of multiple weather systems, the complex terrain, and the sparse instrumental records. Absolutely dated tree-ring records offer the potential to extend our understanding of climate into the pre-instrumental era, but tree-ring studies in this region, and indeed all of tropical Africa, have been rare largely due to lack of an annual climate cycle that reliably produces annual tree-rings. In this study, 40 cores were obtained from 31 Juniperus procera trees growing in the grounds of Ethiopian Orthodox Tewahedo churches in the Gonder region of Ethiopia. The samples were cross-dated using a re-iterative process involving identifying anatomical features from high-resolution images. The tentative ring-width chronologies were revised after the determination of bomb-peak accelerator mass spectrometry radiocarbon dates. Individual series were significantly correlated to the respective master chronologies (r?>?0.55; P?

SUBMITTER: Gebregeorgis EG

PROVIDER: S-EPMC7220890 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands.

Gebregeorgis E Gebrehiwot EG Robertson I I Koprowski M M Zhou L P LP Gao P P Williams A P AP Eshetu Z Z Wils T H G THG

International journal of biometeorology 20200201 5

In the Horn of Africa, little is known about temporal changes in hydroclimate owing to the influence of multiple weather systems, the complex terrain, and the sparse instrumental records. Absolutely dated tree-ring records offer the potential to extend our understanding of climate into the pre-instrumental era, but tree-ring studies in this region, and indeed all of tropical Africa, have been rare largely due to lack of an annual climate cycle that reliably produces annual tree-rings. In this st ...[more]

PMID: 32008098

Similar Datasets

Project description:Juniperus procera is a natural source of bioactive compounds with the potential of antitumor, antimicrobial, insecticidal, antifungal, and antioxidant activities. An optimization method was developed for total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) in leaf and seed extract of Juniperus procera. Organic solvents (methanol (99.8%), ethanol (99%), and acetone (99.5%)), and deionized water (DI) were used for extraction. The estimation of TPC, TFC, and TTC in plant materials was carried out using UV-spectrophotometer and HPLC with the standards gallic acid, quercetin, and tannic acid. Recovery of TPC in leaf extract ranged from 2.9 to 9.7 mg GAE/g DW, TFC from 0.9 to 5.9 mg QE/g DW, and TTC ranged from 1.5 to 4.3 mg TA/g DW while the TPC value in the seed extract ranged from 0.53 to 2.6 mg GAE/g DW, TFC from 0.5 to 1.6 mg QE/g DW, and TTC ranged from 0.5 to 1.4 mg TA/g DW. This result revealed that methanol is the best solvent for recovery of the TPC value (9.7 mg) from leaf extract in comparison to other solvents. Ethanol recorded the highest result of TFC (5.9 mg) in leaf extract among the solvents whereas acetone was the best for TTC yield recovery from leaf extract (4.3 mg). In the case of the seed extract, ethanol was the best solvent for both TPC (2.6 mg), and TFC (1.6 mg) recovery in comparison to other solvents. Total tannin content in methanol resulted in significant recovery from seed extract (1.4 mg). Separation and quantification of gallic acid, quercetin, and tannic acid in plant materials were undertaken using HPLC. Gallic acid in leaf and seed of J. procera ranged from 6.6 to 9.2, 6.5 to 7.2 µg/g DW, quercetin from 6.3 to 18.2, 0.9 to 4.2 µg/g DW, and tannic acid from 16.2 to 29.3, 6.6 to 9.3 µg/g DW, respectively. Solvents have shown a significant effect in the extraction of phenolic compounds. Moreover, phytochemicals in plant materials were identified using GC-MS and resulted in very important bioactive compounds, which include anti-inflammatory, antibacterial, and antitumor agents such as ferruginol, phenanthrene, and n-hexadecanoic acid. In conclusion, the optimal solvent for extraction depends on the part of the plant material and the compounds that are to be isolated.

Project description:Juniperus procera Hochst. ex Endl. is an evergreen highland tree species reaching 30-40 m high and restricted to some mountainous areas. This tree is a species of great ecological and economic significance in supporting biodiversity, preventing soil erosion, and providing valuable resources. The study aimed at comparing the provenances effect on growth and yield performance of a 16-years-old J. procera plantation. This long-term experiment included eleven provenances from different regions of Ethiopia. It was laid out in a randomized complete block design with four replicates. The plot size was 100 m2 with 2.5 m by 2.5 m spacing. Growth parameters such as height and diameter over a 1-m interval of standing trees were measured for sample trees. The results showed that the overall mean of basal area for 11 provenances was ranging from 4.4 ± 0.29 to 5.2 ± 0.33 m2 ha⁻1. The biggest (11.3 ± 0.14 m) and smallest (9.8 ± 0.16 m) mean height was obtained in the provenances of Kolobo and Dikisis, respectively. The mean volume of the stem ranges from 12.3 ± 0.93 to 17.9 ± 1.1 m3 ha⁻1. The highest and lowest form factor was obtained in the provenances of Gaynt (0.43 ± 0.02) and Hirna (0.32 ± 0.02), respectively. The generic form factor is 0.4 ± 0.01. Provenance Kolobo had the best growth rate in all growth stages with 1.4 m height greater than the poorest provenance Dikisis and 23% greater than the overall average volume (14.5 m3 ha⁻1) at age of 16 years. The variations in growth and yield performance among the provenances could be attributed to genetic differences and adaptation to the local environment. Provenances originating from similar altitude such as Kolobo's provenances showed better growth and yield performance, possibly due to their adaptation to the cooler and wetter conditions prevailing in the study area. Choosing provenances that are well-adapted to the local site conditions can lead to improved productivity and economic returns.

Dataset Information

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands.

Publications

Historical droughts recorded in extended Juniperus procera ring-width chronologies from the Ethiopian Highlands.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets