From Traditional Farming in Morocco to Early Urban Agroecology in Northern Mesopotamia: Combining Present-day Arable Weed Surveys and Crop Isotope Analysis to Reconstruct Past Agrosystems in (Semi-)arid Regions

Published by Informa UK Limited, trading as Taylor & Francis GroupWe integrate functional weed ecology with crop stable carbon and nitrogen isotope analysis to assess their combined potential for inferring arable land management practices in (semi-)arid regions from archaeobotanical assemblages. Weed and GIS survey of 60 cereal and pulse fields in Morocco are combined with crop sampling for stable isotope analysis to frame assessment of agricultural labour intensity in terms of manuring, irrigation, tillage and hand-weeding. Under low management intensity weed variation primarily reflects geographical differences, whereas under high management intensity fields in disparate regions have similar weed flora. Manured and irrigated oasis barley fields are clearly discriminated from less intensively manured rain-fed barley terraces in southern Morocco; when fields in northern and southern Morocco are considered together, climatic differences are superimposed on the agronomic intensity gradient. Barley δ13C and δ15N values clearly distinguish among the Moroccan regimes. An integrated approach combines crop isotope values with weed ecological discrimination of low- and high-intensity regimes across multiple studies (in southern Morocco and southern Europe). Analysis of archaeobotanical samples from EBA Tell Brak, Syria suggests that this early city was sustained through extensive (low-intensity, large-scale) cereal farming

Systèmes agrosylvopastoraux oleaster-olive greffés dans le nord du Maroc

International audienceThis book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines.Cet ouvrage, publié par l’Alliance nationale de recherche sur l’environnement (Allenvi) à l’occasion de la 22e Conférence des Parties de la Convention Cadre des Nations unies sur le changement climatique (COP22) de Marrakech, est le fruit de la mobilisation de chercheurs et d’universitaires des deux rives de la Méditerranée. Il constitue une synthèse scientifique exceptionnelle sur les mécanismes du changement climatique, ses impacts sur l’environnement, l’économie, la santé et les sociétés de la Méditerranée. Il représente par ailleurs un précieux outil pour élaborer des réponses, fondées sur l’ « évidence scientifique », en matière d’adaptation, de conservation des ressources, de solutions ou de prévention des risques. Mettant en exergue toute la complexité de l’environnement méditerranéen, cet ouvrage est une contribution scientifique majeure à la question climatique, au croisement des questionnements scientifiques dans une perspective de décloisonnement disciplinaire

Seed size, number and strategies in annual plants: a comparative functional analysis and synthesis

Background and Aims Plants depend fundamentally on establishment from seed. However, protocols in trait-based ecology currently estimate seed size but not seed number. This can be rectified. For annuals, seed number should simply be a positive function of vegetative biomass and a negative function of seed size. Methods Using published values of comparative seed number as the ‘gold standard’ and a large functional database, comparative seed yield and number per plant and per m2 were predicted by multiple regression. Subsequently, ecological variation in each was explored for English and Spanish habitats, newly calculated C-S-R strategies and changed abundance in the British flora. Key Results As predicted, comparative seed mass yield per plant was consistently a positive function of plant size and competitive ability, and largely independent of seed size. Regressions estimating comparative seed number included, additionally, seed size as a negative function. Relationships differed numerically between regions, habitats and C-S-R strategies. Moreover, some species differed in life history over their geographical range. Comparative seed yield per m2 was positively correlated with FAO crop yield, and increasing British annuals produced numerous seeds. Nevertheless, predicted values must be viewed as comparative rather than absolute: they varied according to the ‘gold standard’ predictor used. Moreover, regressions estimating comparative seed yield per m2 achieved low precision. Conclusions For the first time, estimates of comparative seed yield and number for >800 annuals and their predictor equations have been produced and the ecological importance of these regenerative traits has been illustrated. ‘Regenerative trait-based ecology’ remains in its infancy, with work needed on determinate vs. indeterminate flowering (‘bet-hedging’), C-S-R methodologies, phylogeny, comparative seed yield per m2 and changing life history. Nevertheless, this has been a positive start and readers are invited to use estimates for >800 annuals, in the Supplementary data, to help advance ‘regenerative trait-based ecology’ to the next level

Trade-offs between seed and leaf size (seed–phytomer–leaf theory) : functional glue linking regenerative with life history strategies … and taxonomy with ecology?

Background and Aims: While the ‘worldwide leaf economics spectrum’ (Wright IJ, Reich PB, Westoby M, et al. 2004. The worldwide leaf economics spectrum. Nature428: 821–827) defines mineral nutrient relationships in plants, no unifying functional consensus links size attributes. Here, the focus is upon leaf size, a much-studied plant trait that scales positively with habitat quality and components of plant size. The objective is to show that this wide range of relationships is explicable in terms of a seed–phytomer–leaf (SPL) theoretical model defining leaf size in terms of trade-offs involving the size, growth rate and number of the building blocks (phytomers) of which the young shoot is constructed. Methods: Functional data for 2400+ species and English and Spanish vegetation surveys were used to explore interrelationships between leaf area, leaf width, canopy height, seed mass and leaf dry matter content (LDMC). Key Results: Leaf area was a consistent function of canopy height, LDMC and seed mass. Additionally, size traits are partially uncoupled. First, broad laminas help confer competitive exclusion while morphologically large leaves can, through dissection, be functionally small. Secondly, leaf size scales positively with plant size but many of the largest-leaved species are of medium height with basally supported leaves. Thirdly, photosynthetic stems may represent a functionally viable alternative to ‘small seeds + large leaves’ in disturbed, fertile habitats and ‘large seeds + small leaves’ in infertile ones. Conclusions: Although key elements defining the juvenile growth phase remain unmeasured, our results broadly support SPL theory in that phytometer and leaf size are a product of the size of the initial shoot meristem (≅ seed mass) and the duration and quality of juvenile growth. These allometrically constrained traits combine to confer ecological specialization on individual species. Equally, they appear conservatively expressed within major taxa. Thus, ‘evolutionary canalization’ sensu Stebbins (Stebbins GL. 1974. Flowering plants: evolution above the species level. Cambridge, MA: Belknap Press) is perhaps associated with both seed and leaf development, and major taxa appear routinely specialized with respect to ecologically important size-related traits

Genetic diversity of Moroccan grape accessions conserved ex situ compared to Maghreb and European gene pools

Equipe DAVEM = Diversité et Adaptation de la Vigne et des Espèces Méditerranéennes Contact : [email protected] diversity present in Morocco and the part of this diversity used nowadays are poorly documented. In order to choose diversified genotypes, to select them so that their agronomic interest will be tested, a group of 21 autochthonous cultivars preserved in the germplasm collections of SODEA and 18 Moroccan cultivars from "Domaine de Vassal" INRA grape collection was compared to a group of cultivars from neighbouring countries (Algeria and Tunisia), and from a core collection optimizing simple sequence repeat (SSR) allelic diversity of grape. Data from 20 nuclear and 3 chloroplastic SSR markers were obtained for this set of 211 cultivars. A total of 156 alleles (mean of 7.8 alleles per locus) were detected for the nSSRs and 7 alleles for the cpSSR in the Moroccan group. Chlorotype diversity in Moroccan and Algerian group were similar, but slightly lower than in the Tunisian group and the core collection. Similarly, the nSSR diversity was high in the core collection and low in the Moroccan and the Algerian groups compared to the two other groups. Clustering of cultivars based on nSSR data reflected their geographical origin and, to a certain extent, the use of the cultivars. The specificity of the Moroccan plant material was attested by the Bayesian analysis using Structure, while differences of the core collection were clearly revealed both by the Bayesian and a multivariate analysis. These results confirm the differentiation of the material from Maghreb and more specifically of Moroccan material, having evolved independently from Europe