Effects of historical and current disturbance on forest biomass in Minnesota     

Brice B. Hanberry  Hong S. He 《Landscape Ecology》2015,30(8):1473-1482

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Quantitative morphological descriptors confirm traditionally classified morphotypes of <Emphasis Type="Italic">Tamarindus indica</Emphasis> L. fruits     

Belarmain Fandohan  Achille Ephrem Assogbadjo  Romain Glèlè Kakaï  Tina Kyndt  Brice Sinsin 《Genetic Resources and Crop Evolution》2011,58(2):299-309

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Phenotypic variations in fruits and selection potential in Sclerocarya birrea subsp. birrea     

Gerard Nounagnon Gouwakinnou  Achille Ephrem Assogbadjo  Anne Mette Lykke  Brice Sinsin 《Scientia Horticulturae》2011

The domestication of indigenous fruits through agroforestry is seen as one of the important issues in the transformation in the way in which land is used within rural areas. A study of the variation in fruit traits is also important as it is a prerequisite for cultivar development in the domestication process. Following an aridity gradient, phenotypic variation was assessed in fruits of Sclerocarya birrea subsp. birrea, native to West African semi-arid areas. Fruits were collected from 42 trees of various diameters in agroforestry parklands from the dry and semi-humid Sudanian zones. They were partitioned into peel, flesh and pit. Each fruit was labelled and its components were measured and weighted. The overall mean fruit mass was 18.58 ± 0.24 g (mean ± SE) but fruits from the population in the drier zone were significantly larger (19.90 ± 0.37 g vs 17.02 ± 0.24 g; P < 0.001). The results showed a strong correlation between fruits and their components (P < 0.05). Tree diameter was very weakly correlated with fruit traits. There was a high level of variation in fruit characteristics and components within and between populations. The within-population variation accounted for the greatest part (67–100%) of the total variation. Many trees, mainly from the drier zones, showed superior phenotypic traits. Five groups of trees which represented different fruit morphotypes were identified for various prospective exploitations. The results strongly support the implementation of preliminary practical conservation action and domestication of S. birrea in West Africa.  相似文献   

Agelasine Diterpenoids and Cbl-b Inhibitory Ageliferins from the Coralline Demosponge Astrosclera willeyana     

Wei Jiang  Dongdong Wang  Brice A. P. Wilson  Unwoo Kang  Heidi R. Bokesch  Emily A. Smith  Antony Wamiru  Ekaterina I. Goncharova  Donna Voeller  Stanley Lipkowitz  Barry R. O&#x;Keefe  Kirk R. Gustafson 《Marine drugs》2021,19(7)

An extract of the coralline demosponge Astrosclera willeyana inhibited the ubiquitin ligase activity of the immunomodulatory protein Cbl-b. The bioassay-guided separation of the extract provided ten active compounds, including three new N-methyladenine-containing diterpenoids, agelasines W–Y (1–3), a new bromopyrrole alkaloid, N(1)-methylisoageliferin (4), and six known ageliferin derivatives (5–10). The structures of the new compounds were elucidated from their spectroscopic and spectrometric data, including IR, HRESIMS, and NMR, and by comparison with spectroscopic data in the literature. While all of the isolated compounds showed Cbl-b inhibitory activities, ageliferins (4–10) were the most potent metabolites, with IC₅₀ values that ranged from 18 to 35 μM.  相似文献   

National inventory and prioritization of crop wild relatives: case study for Benin     

Rodrigue Idohou  Achille Ephrem Assogbadjo  Belarmain Fandohan  Gerard Nounagnon Gouwakinnou  Romain Lucas Glele Kakai  Brice Sinsin  Nigel Maxted 《Genetic Resources and Crop Evolution》2013,60(4):1337-1352

Species prioritization is a crucial step in any development of conservation strategy, especially for crop wild relatives (CWR), since financial resources are generally limited. This study aimed at: assessing the biodiversity of crop wild relatives in Benin and identifying priority species for active conservation. Data were collected through literature review to establish an exhaustive list of CWR in Benin. Eight prioritization criteria and different prioritization systems were used. The top 50 species obtained by each of these methods were identified and twenty final top CWR were shortlisted as those occurring as priority across methods. A total of 266 plant species belonging to 65 genera and 36 families were identified. The most represented are: Cyperaceae (12.50 %), Leguminosae-Papilionoideae (11.87 %), Convolvulaceae (11.25 %), Poaceae (10.31 %), Asteraceae (7.81 %), Solanaceae (6.87 %) and Dioscoreaceae (5.31 %). Among the 20 species of highest priority for conservation, Manihot glaziovii Müll. Arg. and Piper guineense Schumach. et Thonn., appeared as the most represented species on top of the list.  相似文献   

Sudden Oak Death, A New Forest Disease in California     

Brice A. McPherson  David L. Wood  Andrew J. Storer  N. Maggi Kelly  Richard B. Standiford 《Integrated Pest Management Reviews》2001,6(3-4):243-246

A forest disease caused by a newly described pathogen, Phytophthora ramorum, is presently affecting a number of woody plant species in central and northern coastal California and southern Oregon, U.S.A. Among the most severely affected tree species are coast live oak, Quercus agrifolia, and tanoak, Lithocarpus densiflorus. In March 2000, we established plots in Marin County, CA, to assess symptom progression and the association of other organisms with diseased trees. Symptomatic trees exhibit 'bleeding' of viscous sap from apparently intact bark, typically within approximately 2 m of the soil. At least three species of bark and ambrosia beetles colonize bleeding oaks. These beetles colonized every bleeding tree that died during the first year of the study (N = 23) while the foliage was still green. By March 2001, numbers of symptomatic and dead trees increased for both coast live oak and tanoak. Symptomatic coast live oaks totaled 26% in March 2000 and 27% in March 2001. During the same period, mortality increased from 6% to 10%. For tanoaks, 41% were symptomatic in 2000, rising to 49% in 2001. Mortality was 11% in 2000 and 13% in 2001. The values for coast live oak are broadly consistent with independently acquired infection and mortality estimates derived from an unbiased transect method.  相似文献   

Allometric equations from a non-destructive approach for biomass prediction in natural forest and plantation in West Africa     

SA Hamzath Kora  Cédric A Goussanou  Achille E Assogbadjo  Brice Sinsin 《Southern Forests》2019,81(2):111-122

Allometric equations are required for a rapid estimation of commercial timber volume and forest biomass stocks. In order to preserve the forest ecosystem, this study applied a non-destructive sampling approach to measure biophysical properties of living trees. From these measurements, volume and biomass models were developed for 11 dominant tree species in a semi-deciduous natural forest and for Acacia auriculiformis in a plantation located in southern Benin. The observations were combined to develop also generic models applicable to non-dominant tree species. Wood samples of the tree species were collected with an increment borer and analysed in the laboratory to determine species-specific wood densities. The sample size was composed of 243 trees in natural forest and 21 trees in plantation. The measurements were conducted in 30 plots of 50 m × 50 m. The graphical assessment of correlation between model outputs (biomass and volume) and variables (diameter and height) and the statistical analysis confirmed that the logarithmic model with two variables had the best predictions. The assessment also confirmed that the model using diameter only as a variable had good predictions when observations on height were unavailable. The comparative analysis of model predictions showed that the generic model in this study over-estimated biomass by up to 74.80% for certain species and under-estimated biomass by 21.18% for other species. The study shows that there are no statistically significant differences between the wood densities in this research and that published in previous studies.  相似文献   

Changes during early development in photosynthetic light acclimation capacity explain the shade to sun transition in Nothofagus nitida     

Coopman RE  Reyes-Díaz M  Briceño VF  Corcuera LJ  Cabrera HM  Bravo LA 《Tree physiology》2008,28(10):1561-1571

Nothofagus nitida (Phil.) Krasser, an emergent tree of the Chilean evergreen forest, regenerates under the canopy. Nonetheless, it is common to find older saplings in clear areas. We hypothesized that this transition from shade to sun during the early developmental stages is made possible by an ontogenetic increase in the light acclimation capacity of photosynthesis. To test our hypothesis, we studied photosynthetic performance and photoprotection in N. nitida saplings at different developmental stages corresponding with three different height classes (short: 16.2 cm; medium-height: 48.0 cm; and tall: 73.7 cm) grown under contrasting light conditions (photosynthetic photon flux (PPF) of 20, 300 or 600 micromol m(-2) s(-1)) until newly expanded leaves had developed. Light-saturated CO(2) assimilation rate and light compensation and saturation points increased with increasing PPF. Medium-height and tall saplings acclimated to high light had higher electron transport rates and higher proportions of open Photosystem II reaction centers than shorter plants acclimated to high light. Short saplings showed higher thermal dissipation and contents of xanthophylls than taller saplings. Only medium-height and tall saplings acclimated to high light recovered after photoinhibition. State transitions were higher in short plants growing in low light, and decreased with plant height and growth irradiance. Thus, during development, N. nitida changes the balance of light energy utilization and photoprotective mechanisms, supporting a phenotypic transition from shade to sun during its early ontogeny.  相似文献   

Land use impact on Vitellaria paradoxa C.F. Gaerten. stand structure and distribution patterns: a comparison of Biosphere Reserve of Pendjari in Atacora district in Benin     

Bruno Agossou Djossa  Jakob Fahr  T. Wiegand  B. E. Ayihouénou  E. K. Kalko  B. A. Sinsin 《Agroforestry Systems》2008,72(3):205-220

The shea tree, Vitellaria paradoxa, is a socio-economically important tree for the rural population in parts of West Africa. Our study assessed the current status of this native tree species with regard to increasing human pressure in northern Benin. We compared distribution of adult shea trees, seedlings and saplings in farmed lands with protected areas in the Biosphere Reserve of Pendjari (BRP). At our study site near BRP, agricultural activities foster recruitment of shea trees by regularly cropping of vegetation cover. Furthermore, traditional farming practices preserve adult individuals thus permitting regular fruit harvests. Consequently, most of the tallest and largest individuals of shea trees are found in framed lands. In contrast, the highest density of juvenile trees including seedlings (dbh <5 cm) and saplings (dbh 5–10 cm) occurred within BRP. Saplings were negatively affected by farming activities. Furthermore, spatial point pattern analysis revealed differences in the spatial structure of juveniles. Juveniles showed significant aggregations at small scale (<20 m) in BRP as well as significant and positive small-scale associations with adult trees. This contrasts with farmed lands where we did not find such spatial patterns at similar small scale but only a weak aggregation between juveniles and absence of association (attraction) of adults to juveniles. Although our analyses indicate that shea trees are rather well preserved, we conclude that the observed severe reduction of saplings in farmed lands is likely to negatively impact the long-term viability of the tree population. Therefore agroforestry practices must consider the preservation of sapling populations in farming areas for long-term conservation.  相似文献   

Genetic fingerprinting using AFLP cannot distinguish traditionally classified baobab morphotypes     

A. E. Assogbadjo  T. Kyndt  F. J. Chadare  B. Sinsin  G. Gheysen  O. Eyog-Matig  P. Van Damme 《Agroforestry Systems》2009,75(2):157-165

Baobab (Adansonia digitata L.) is one of the predominant tree species in West African agroforestry systems. A local morphological classification system is used by farmers, identifying trees with desired or undesired combinations of traits. This study evaluates the genetic significance of these morphotypes by comparing local identification with AFLP marker information. Eight morphotypes were recognized by seven ethnic groups from Benin, Ghana and Senegal, among 182 sampled baobab trees. Five primer pairs were used for DNA fingerprinting, resulting in a total of 254 scored bands, of which between 94.1% and 100% was polymorphic within morphotypes. Generally, genetic fingerprinting did not correlate with the traditional morphological identification of Adansonia digitata. Probably, AFLP markers are not directly linked to the differences in phenotype or the traits used for the traditional classification are largely dependent on environmental factors. Since no genetic differentiation is found between the morphotypes, a morphotype-based approach in the collection of genetic variation for conservation programs is not advisable. A. E. Assogbadjo and T. Kyndt equally contributed to this work.  相似文献