Agroecology has become increasingly popular but locally optimized agroecological production methods and information and communication technology (ICT) support tools are limited. This study was conducted at three different geographic locations across Tanzania; we co-developed an integrated participatory field research methodology consisting of two components, each supported by a specifically developed, complementary ICT tool, with maize and cassava as the two focal crops, to examine soil fertility and conservation (compost and mulching), increased biodiversity through intercropping (legumes), and organic pest control measures. Two specifically developed ICT tools, the AgroEco Research application (AER) and AgroEco Analysis application (AEA) were used for data gathering & storage and visualization & statistical analysis, respectively. Further, farmer-managed satellite experiments were performed to further test the research premises and validate their outcomes in the "real world" of smallholder farmers, which was supported by a smartphone application called "Ugunduzi" - enabling farmers to collect, store, and evaluate data generated at different stages of their research. Farmers were free to choose any type, number, and combination of the agroecological practices tested in the field research. This study serves as a methodology reference for a number of companion publications reporting on the findings of this project.
Agroecology is gaining increased attention by experts and global organizations; however, it's practical application in the field remains understudied, particularly in developing countries. Here, we aimed to evaluate common agroecological practices at three sites in Tanzania, including organic soil amendments, intercropping, and biological pest control - individually, in pairs, or in three-way combinations at each site. Information Communication Technology tools - the AgroEco Research and AgroEco Analysis application - were used for data gathering & storage and data visualization & statistical analysis, respectively. We found that high maize kernel weights (as proxy for yield) can be obtained from nutrient-poor soils specifically when grown with a combination of organic soil amendments and intercropped with legumes - ranging from 3 to 4.5 t/ha (with a maximum of 7 t/ha on one occasion) and exceeding national maize yields of 1-2 t/ha in Tanzania. However, intercropping and biological pest control individually and in combination did not affect maize yield. Under flood or drought conditions, only plots with soil fertility amendments produced some harvestable maize kernels. Our results provide a substantial reference for recommending and advocating agroecological methods to smallholder farmers, farmer training organizations, and policy makers. [GRAPHICS] .
This study discusses the results of a 5-year Agroecology Research and Advocacy project at three Tanzanian field sites in different agroecological zones. We investigated four common agroecological practices: compost application, mulching, intercropping, and biological pest control either alone or in combination. Two custom-built ICT tools - AgroEco Research (AER) and AgroEco Analysis (AEA) application - supported the field research. AER and AEA integration allowed secure data storage and real-time automated visualization and statistical analyses without programming. At no field station did legume intercropping or biological pest control increase cassava yields. The Chambezi field station had the highest yields even under untreated control conditions and only here, soil fertility amendments further increased root weights. Intercropping with cowpea legumes, alone or in combination with other practices, had no significant effect on cassava plant size or survival at the Mumbaka and Vianzi field sites and even negatively affected one or both parameters. Organic pest control had no effect on any target variable, except for plant size at Chambezi. Therefore, labor-intensive and expensive pest control practices may not be worth the investment at least when virus-resistant cassava varieties like Kiroba are used.
Rosewood and palisander (Dalbergia L.f., Fabaceae) are sources of highly valuable tropical timber and include species threatened by habitat degradation and selective logging for national and international trade. Law enforcement depends on reliable and cost-effective species-level identification of timber along the supply chain. The potential of wood anatomy to distinguish between species has not yet been systematically investigated for Dalbergia species from Madagascar. We assessed 36 qualitative and eight quantitative wood anatomical features in 16 Malagasy Dalbergia species that form medium-sized to large trees, representing each species by at least five individuals. We integrated and contrasted the newly collected data with existing data from InsideWood and two previous studies. Principal component analysis of 93 individuals and 29 variables resulted in non-overlapping hulls for eight species with respect to the first two dimensions. Four quantitative features (number of ray tiers per millimetre, number of rays per millimetre, vessel density, and vessel element length) and two qualitative features (scanty paratracheal axial parenchyma and irregular to absent storied structure) were found to be potentially diagnostic to distinguish three single species and three pairs of closely related species. Following our analyses, we provide a provisional microscopic wood anatomical identification key for the 16 Dalbergia species, which can be applied to both logs and sawn wood.
An ongoing revision of Malagasy Dalbergia L. f. (Fabaceae) has increased the number of recognized species from 48 to 64. Fifty-two (52) of the 64 are considered to grow large enough to be of potential commercial interest for their valuable timber. Eight large tree species, mostly from the north and west of Madagascar, are described and illustrated here for the first time, namely Dalbergia bosseri N. Wilding, Phillipson & Crameri; D. karatrae N. Wilding, Phillipson & Crameri; D. leandrii N. Wilding, Phillipson & Crameri; D. oronjiae N. Wilding, Phillipson & Crameri; D. rajeryi N. Wilding, Phillipson & Crameri; D. rakotovaoi Phillipson, N. Wilding & Crameri; D. sambavensis N. Wilding, Phillipson & Crameri and D. soafarae N. Wilding, Phillipson & Crameri. Risk of extinction assessments using the IUCN Red List criteria are provided and indicate that all eight species are threatened.
Dalbergia emirnensis Benth. was previously treated as comprising two entities, the typical variety from the Central Highlands of Madagascar and D. emirnensis var. decaryi Bosser & R. Rabev. from the southern part of the country at lower altitudes. Additional collections and analyses demonstrate that, as currently delimited, these taxa exhibit considerable, discontinuous variability in morphology, habitat, and distribution, a finding supported by a recent phylogenomic study. We show that the material previously included in the typical variety of D. emirnensis represents two morphologically and geographically distinct entities, one that occurs only in the Central Highlands of Madagascar and includes the type specimen, and another that is morphologically and genetically more akin to D. emirnensis var. decaryi, found in the Southern Highlands of Madagascar. We describe the latter as a new species, D. nemoralis Rakoton., Phillipson & Crameri, in which we include D. emirnensis var. decaryi, recognizing it as a distinct subspecies. We also show that D. campenonii Drake should be treated as a synonym of D. emirnensis. Each of the accepted taxa is provided with a full description, a comprehensive listing of specimens examined, details of its geographic distribution and habitat, and a provisional risk of extinction assessment using the IUCN Red List categories and criteria; a line drawing is also provided for D. nemoralis subsp. nemoralis.
Understanding the genetic changes associated with the evolution of biological diversity is of fundamental interest to molecular ecologists. The assessment of genetic variation at hundreds or thousands of unlinked genetic loci forms a sound basis to address questions ranging from micro-to macro-evolutionary timescales, and is now possible thanks to advances in sequencing technology. Major difficulties are associated with i) the lack of genomic resources for many taxa, especially from tropical biodiversity hotspots, ii) scaling the numbers of individuals analyzed and loci sequenced, and iii) building tools for reproducible bioinformatic analyses of such datasets. To address these challenges, we developed a set of target capture probes for phylogenomic studies of the highly diverse, pantropically distributed and economically significant rosewoods ( Dalbergia spp.), explored the performance of an overlapping probe set for target capture across the legume family (Fabaceae), and built a general-purpose bioinformatics pipeline. Phylogenomic analyses of Dalbergia species from Madagascar yielded highly resolved and well supported hypotheses of evolutionary relationships. Population genomic analyses identified differences between closely related species and revealed the existence of a potentially new species, suggesting that the diversity of Malagasy Dalbergia species has been underestimated. Analyses at the family level corroborated previous findings by the recovery of monophyletic subfamilies and many well-known clades, as well as high levels of gene tree discordance, especially near the root of the family. The new genomic and bioinformatics resources will hopefully advance systematics and ecological genetics research in legumes, and promote conservation of the highly diverse and endangered Dalbergia rosewoods.
The Malagasy rosewood species Dalbergia maritima has a long history of unsustainable exploitation for its beautiful, burgundy-colored heartwood. As currently circumscribed, D. maritima has a wide geographic distribution in eastern Madagascar and exhibits significant morphological, ecological, and genetic variation, suggesting it may comprise more than a single entity. Multivariate analyses of leaf, flower, and inflorescence characters as well as eco-geographic features reveal several morphologically well delimited entities with distinct habitat preferences and/or geographic ranges, which are consistent with results from recent phylogenomic and population genomic studies of Malagasy Dalbergia. Based on these findings, we describe and illustrate two new species from southeastern Madagascar comprising material previously assigned to D. maritima, viz. D. pseudomaritima, characterized by paniculate inflorescences and small, broadly elliptic to orbicular, glabrous leaflets, and D. razakamalalae, distinguished by racemose inflorescences with large flowers, and narrowly ovate to narrowly elliptic, glabrous leaflets. Dalbergia maritima is consequently re-circumscribed to include only populations from east-central Madagascar, within which we recognize two subspecies, D. maritima subsp. maritima, with glabrous leaves, inflorescence axes, and gynoecia, occurring in littoral forest habitats, and D. maritima subsp. pubescens, with indument on these structures, and growing in evergreen humid forest farther inland. Photos are provided for each taxon, along with line drawings for the two new species. Provisional IUCN Red List assessments indicate that all three species are Endangered, D. maritima and D. razakamalalae mainly because of selective logging for trade in their high-quality heartwood, and D. pseudomaritima primarily because of habitat degradation due to land clearing and fire for subsistence agriculture, which has important implications for their conservation and sustainable management.
Two new species of Dalbergia L. f. (Fabaceae: Dalbergieae) are described from northern Madagascar: Dalbergia antsirananae Phillipson, Crameri & N. Wilding and Dalbergia obcordata N. Wilding, Phillipson & Crameri, and an emended description is provided for a third species, Dalbergia manongarivensis Bosser & R. Rabev. All three species are illustrated with line drawings and photographs, and each is provided with a risk of extinction assessment using the IUCN Red List criteria: all three species are assessed as "Endangered". Dalbergia antsirananae and Dalbergia manongarivensis are closely related, and both appear to be a source of valuable wood, while Dalbergia obcordata is only known as a shrub and is assumed not to produce wood of commercial value.
The two varieties of Dalbergia mollis Bosser & R. Rabev., recognised by Bosser & Rabevohitra, have been recently shown on the basis of molecular data to be distinct at species level. This distinction is supported by a number of clear differences in the morphology of the two species that we discuss here in detail. Nomenclatural problems have beset these taxa: the name Dalbergia mollis was established by Bosser and Rabevohitra as a replacement for the later homonym Dalbergia stenocarpa R. Vig., however, the name was superfluous because the name Dalbergia chermezonii R. Vig. was available for this species as circumscribed in Bosser and Rabevohitra's article, but was treated by the authors incorrectly, as a synonym of one of the varieties. We re-establish Dalbergia chermezonii, provide the new name, Dalbergia bemarivensis Phillipson & N. Wilding, as a replacement for Dalbergia stenocarpa R. Vig. and propose an amended description of both species. While the former species occurs only in the southern half of the country, the latter occurs only in the north-west. Both species can become large trees and are known to be a source of valuable rosewood.
A putatively monophyletic group of annual Silene species is revised taxonomically and described as the new section S. sect. Arenosae. The species of this section were previously treated as a part of a widely circumscribed and polyphyletic S. sect. Rigidulae. Silene sect. Arenosae as circumscribed here consists of nine species. Members of the section show a predominantly E Mediterranean to SW Asian distribution pattern from Turkey southward to Egypt and eastward to Iran and Pakistan, although most of the species have a limited distribution range. The species of S. sect. Arenosae are characterized by narrowly lanceolate calyx teeth, which are often highly polymorphic, and lanceolate to oblanceolate (non-spathulate) basal leaves. The provided taxonomic revision is based on morphological characters and supported by phylogenetic analyses of two nuclear loci (nrITS and an intron of the RPB2 gene) and one chloroplast locus (the intron of the rps16 gene). The species descriptions are formalized using a novel implementation of the Prometheus Description Model.