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Global population projections foresee the biggest increase to occur in Africa with most of the available uncultivated land to ensure food security remaining on the continent. Simultaneously, greenhouse gas emissions are expected to rise due to ongoing land use change, industrialisation, and transport amongst other reasons with Africa becoming a major emitter of greenhouse gases globally. However, distinct knowledge on greenhouse gas emissions sources and sinks as well as their variability remains largely unknown caused by its vast size and diversity and an according lack of observations across the continent. Thus, an environmental research infrastructure—as being setup in other regions—is more needed than ever. Here, we present the results of a design study that developed a blueprint for establishing such an environmental research infrastructure in Africa. The blueprint comprises an inventory of already existing observations, the spatial disaggregation of locations that will enable to reduce the uncertainty in climate forcing’s in Africa and globally as well as an overall estimated cost for such an endeavour of about 550 M€ over the next 30 years. We further highlight the importance of the development of an e-infrastructure, the necessity for capacity development and the inclusion of all stakeholders to ensure African ownership.

Smallholder farmers struggle to achieve food security in many countries of sub-Saharan Africa (SSA). It is urgently required to find appropriate practices for enhancing crop production while avoiding large increases in greenhouse gas (GHG) emissions in SSA. This review aims to identify common smallholder farming practices for enhancing crop production, to assess how these affect GHG emissions and to identify strategies that not only enhance crop production but also mitigate GHG emissions in SSA. To increase crop production and ensure food security, smallholder farmers usually expand agricultural land, develop water harvesting and irrigation techniques and increase cropping intensity and fertilizer use. These practices may result in changing carbon stocks and GHG emissions, potentially creating trade-offs between food security and GHG mitigation. Agricultural land expansion at the expense of forests is the most dominant source of GHG emissions in SSA. While water harvesting and irrigation can increase soil organic carbon, they can trigger GHG emissions. Increasing cropping intensity can enhance the decomposition of soil organic matter, thus releasing carbon dioxide. Increasing nitrogen fertilizer use can enhance soil organic carbon, but also leads to increasing nitrous oxide emissions. An integrated land, water and nutrient management strategy is necessary to enhance crop production and mitigate GHG emissions. Among the most relevant strategies found, agroforesty practices in degraded and marginal lands could replace expanding agricultural croplands. In addition, water management, via adequate rainwater harvesting and irrigation techniques, together with appropriate nutrient management should be considered. Therefore, a land-water-nutrient nexus (LWNN) approach will enable an integrated and sustainable solution to increasing crop production and mitigating GHG emissions. Various technical, economic and policy barriers hinder implementing the LWNN approach on the ground, but these may be overcome through developing appropriate technologies, disseminating them through farmer to farmer approaches and developing specific policies to address smallholder land tenure issues and motivate long-term investment.

A relatively small number of broad-scale patterns describe the distribution of biodiversity across the earth. All of them explore biodiversity focusing on a mono or bi-dimensional space. Conversely, the volume of the forests is rarely considered. In the present work, we tested a global correlation between vascular plant species richness (S) and average forest canopy height (H), the latter regarded as a proxy of volume, using the NASA product of Global Forest Canopy Height map and the global map of plant species diversity. We found a significant correlation between H and S both at global and macro-climate scales, with strongest confidence in the tropics. Hence, two different regression models were compared and discussed to provide a possible pattern of the H–S relation. We suggested that the volume of forest ecosystems should be considered in ecological studies as well as in planning and managing natural sites, although in this first attempt, we cannot definitively prove our hypothesis. Again, high-resolution spatial data could be highly important to confirm the H–S relation, even at different scales.

BACKGROUND: A likely increasing demand for varieties mixtures, landraces and genetic diversity in cropping systems will underpin calls for models able to generalize phenological development at the species level, at the same time as providing the expected range of phenological variability. In the present article, we aimed to obtain a generalized phenological model of durum wheat (Triticum durum, Desf.). RESULTS: Using a large phenological dataset embracing field data collected under different sowing dates, varieties and locations over the Italian peninsula, we searched for the phenophases enabling the best linear approximations between developmental rates and air temperature, aiming to minimize the residual variability from drivers other than temperature, as genetic and environmental diversity. The developmental rates of the resulting phases were then examined with respect to the mean daylength to determine possible additional relations with photoperiod. If a correlation with daylength was also present, the developmental rate is calibrated by multiple linear regression, or otherwise by simple linear regression of temperature. The resulting calibration, tested on an independent data subset, confirms that the model is able to generalize wheat development over the Italian peninsula with high accuracy (mean absolute error =3–8 days; r2 = 0.75–0.98), regardless of the wheat variety. CONCLUSION: The generalized phenological model is potentially suitable for many agro-ecological and large-scale applications. It is hoped that the model will aid in situations where phenological observations to parameterize a model are still lacking, as is probably the case for landraces and underutilized crop varieties. © 2019 Society of Chemical Industry.

This is the pre-print version of the chapter"Climate change sustainable agriculture and food systems_The world after the Paris agreement"published as final paper inAchieving the Sustainable Development Goals Through Sustainable Food Systems,10 October 2019, Pages 1-262https://doi.org/10.1007/978-3-030-23969-5 lntroduction 1.1 Climate Change and Agriculture According to the fifth assessment report of the IPCC (2014), the concentrations of greenhouse gases (GHG) in the atmosphere are at the highest they have been in the past 800 thousand years. Current levels of CO2 have increased by 30% from 280 ppm in pre-industrial times to 407 ppm today (2019), and they continue to rise. Present CH4 concentrations of 2000 ppb are nearly triple their pre-industrial value of 700 ppm. N2O levels reached 328 ppb in 2019 compared with the 280 ppb of pre-industrial time. Only in the past 50 years we have doubled human population (from 4 to 7 billion), increased GHG emissions by 2.5 times, doubled freshwater withdrawal, halved the agricultural land per capita (from 1. 4 to 0.7 ha) by agricul­ture intensification. This is an unprecedented velocity of transformation that our Planet and human society had never experienced. Today, the agro-food sector alone accounts for some 80% of the world freshwa­ter use, 30% of world energy demand, and more than 12% of man-made greenhouse gas emissions worldwide, including indirect emissions such as those of deforesta­tion (Foley et al. 2011). Moreover, according to the Food and Agriculture Organization (FAO) of the United Nations, croplands and pastures occupy about 38% of Earth's terrestrial surface, the largest use of land on the planet (Foley et al. 2011). With global food production expected to increase 70% by 2050, and consid­ering the meat dietary changes, the sector is facing unprecedented resource pres­sures and strong perturbations to the climate systems. By 2050 more than nine billion of people will be in search of food and most of them (68%) will be living in mega-cities (UN DESA 2018). Under these circumstances, a substantial redefinition of the actual food supply chain is essential. Meanwhile, many rural-communities, which strongly depends on domestic-subsistence agriculture, will be exposed to food scarcity and accessibility. lndeed, in some regions of the world (i.e. tropics and part of temperate regions) increasing of climate extremes will produce adverse effects on agriculture, forestry and fisheries sectors with yield reduction of 35% in African countries and 2% globally per decade, despite the increasing food demand (Barros et al. 2014). It is time to reflect on the global agro-food systems, its para­ doxes, inequalities and capacities to support future generations. On the other side global warming can also expand the land suitability for some crops, like wheat at high latitudes (Di Paola et al. 2018). Humanity needs to act urgently and fast, push­ ing the high-level governmental agenda (SDGs, Climate Paris agreement) as well as industry sector and citizens in the most difficult and challenging transformation of our society to feed the new two billion of people expected by 2050 and, at same time, stabilize climate below 2.0° (possibly 1.5°) and reducing the pressures on natural resources. 1.2The Paris Agreement: Implications for the Agriculture Sector The significant role that agriculture can play in climate change was relatively under­ represented in the previous discussions and decisions under the frame of the United Nations Framework Convention on Climate Change (UNFCCC), before the Paris Agreement (PA) was adopted by the 21st Conference of the Parties (COP21) of the UNFCCC on the 12th of December 2015. Food security and food production are explicitly mentioned in the PA: in its pre­ amble the Parties recognize "the fundamental priority of safeguarding food security and ending hunger, and the particular vulnerabilities of food production systems to the adverse impacts of climate change", and the Artide 2 highlights the importance of "increasing the ability to adapt to the adverse impacts of climate change and foster climate resilience and low greenhouse gas emissions development, in a man­ ner that does not threaten food production". Moreover, the role of agriculture in the PA is also linked to the capacity to be a possible sink and reservoir of GHG in soils and vegetation biomass: in the Artide 5 Parties are invited to "take action to con­ serve and enhance, as appropriate, sinks and reservoirs of greenhouse gases". This opened to agriculture as a key sector, not only impacted by climate change but also with a great potential for mitigation. In fact, more in generai, the PA has the ambition to keep "the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change". In order to achieve this long-term temperature goal, parties are therefore committed to achieve a balance between anthropogenic emissions by sources and removals by sinks in the second half of this century. Different options are feasible and the agriculture sector can play an active role, in particular by contributing to the net emissions reduction, while guaranteeing food security. Besides, under the UNFCCC processa specific programme on agriculture was launched (the "Koronivia Joint Work on Agriculture", see Box below) that provides space and opportunities for Parties to fully engage on climate related discussions in the agriculture sector in order to foster actions related to adaptation and mitigation taking into consideration the sectors vulnerabilities. In pathways limiting global warrning to 1.5 °C with limited or no overshoot, Agriculture, Forestry and Other Land-Use (AFOLU) related carbon dioxide removal measures are projected to remove 0-5, 1-11, and 1-5 GtCO2 year- 1 in 2030, 2050, and 2100 respectively (IPCC 2018). Due to this key potential role plaid by the agri­ culture, the 80% of the Nationally Determined Contributions (NDCs) submitted by countries committed to actions on agricultural mitigation, and 90% ofNDCs selected agriculture as a priority sector for action on adaptation (CCAFS 2016; FAO 2016). Despite the inclusion of agriculture and the land sector in general in most NDC, this is still not enough to achieve the 2 °C goal and additional reduction targets are needed (Fujimori et al. 2016). According to the Fujimori et al. (2016) modelling exercise, large-scale negative CO2 emissions and land-based CO2 emissions­ reduction measures are required and the bioenergy crops need to be an important component in addition to agriculture, with an area of cropland used for bioenergy to be 24-36% of the total cropland. Indeed, the deployment of such a large-scale land­ related measures, like afforestation and bioenergy supply, can compete with food production raising not only food security concerns (IPCC 2018) but also increasing the environmental footprint, due to the increased use of natural resource (e.g. water and nitrogen for bioenergy crops) and environmental impacts (e.g. loss of biodiver­sity and increasing pollution from fertilizers). Furthermore, climate-related risks on food security are projected to increase under global warming, with projected net reductions in maize, rice, wheat and, potentially, other cereal yields in many regions of the world (IPCC 2018). Studies based on multi-model inter-comparisons (Schleussner et al. 2016) fore­ see a general crop yield reduction, particularly in tropics, for maize and wheat under increasing temperature scenarios, with more significant reductions projected at 2 °C than 1.5 °C. On the other side, local rice and soy yields are projected to increase in the tropics, as the positive effect of CO2 fertilization counterbalances the detrimen­tal impacts of climate change in the model projections (Schleussner et al. 2016). However, additional gains for warming above 1.5 °C resulted not significant, and yield reductions are expected for all the four widespread global crops. In the light of these evidences, trade-offs between mitigation and adaptation, as well as economie and environmental benefits, need to be addressed when balancing the need of land for bioenergy crops, reforestation or afforestation, versus the land needed for agricultural adaptation under a changing climate, not undermining food security, livelihoods, ecosystem functions and services and other aspects of sustain­able development.

Vegetation phenology and its variability have substantial influence on land-atmosphere interaction, and changes in growing season length are additional indicators of climate change impacts on ecosystems. For these reasons, global land surface models are routinely evaluated in order to assess their ability to reproduce the observed phenological variability. This work presents a new approach that integrates a wider spectrum of growing season modes in order to better describe the observed variability in vegetation growing season onset and offset, as well as assess the ability of state-of-the-art land surface models to capture this variability at the global scale. The land surface models results are validated against the LAI3g satellite-observation. The comparison between data and model outputs shows the ability of models in reproducing the growing season features in the boreal forests, but also displays their limitations located, for example, in areas where water availability acts as the main driver of vegetation phenological activity. In general, the new methodology expands the area of analysis from northern mid- and high-latitudes to the global continental areas, and allows to assess the vegetation response to the on-going climate change in a larger variety of ecosystems, ranging from rain forests to semi-arid regions, passing through boreal evergreen and temperate deciduous forests. This effort is part of the EU-funded CRESCENDO project. Keywords: Phenology, modeling, vegetation growing season.

The emergence of Russia as a major grain exporter is not only crucial for the world commercial agriculture and food security, but also for the country’s economy. Here we examine the past-to-future thermal suitability for winter wheat (Triticum aestivum, L. 1753) cultivation over Russia and compare it with the recent trends of wheat yields and harvested area. The analyses use a multi-model ensemble median of the most updated bias-corrected outputs from five CMIP5 Earth System Models (1950–2099) under two representative concentration pathways (RCP 4.5 and RCP 8.5) and the Era-Interim dataset (1979–2016). Our results show that the thermal suitability has increased by ∼10 Mha per decade since 1980. Consistently, winter wheat yields and harvested area have also increased over the last decade by ∼0.5 t/ha and ∼4 Mha, respectively. Moreover, a potential for the Russian wheat sector may still be exploited if we consider the abandoned land (∼27 Mha) after the collapse of the Soviet Union. Our results also show that the increase in heat availability and the reduction of the frost constraint will likely move the thermal suitability toward the north-western and the Far East regions. Conversely, increases of extreme heat events are projected in the southern regions of Russia, which currently represent the most productive and intensively managed wheat cultivation area. Our findings imply both opportunities and risks for the Russian wheat sector that calls for sustainable and farsighted land management strategies to comprehensively face the consequences of global warming.

International audience; This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (CO 2 , CH 4 and N 2 O) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodolo-gies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average value of Published by Copernicus Publications on behalf of the European Geosciences Union. 382 R. Valentini et al.: A full greenhouse gases budget of Africa −0.61 ± 0.58 Pg C yr −1. Nevertheless, the emissions of CH 4 and N 2 O may turn Africa into a net source of radiative forcing in CO 2 equivalent terms. At sub-regional level, there is significant spatial variability in both sources and sinks, due to the diversity of biomes represented and differences in the degree of anthropic impacts. Southern Africa is the main source region; while central Africa, with its evergreen tropical forests, is the main sink. Emissions from land-use change in Africa are significant (around 0.32 ± 0.05 Pg C yr −1), even higher than the fossil fuel emissions: this is a unique feature among all the continents. There could be significant carbon losses from forest land even without deforestation, resulting from the impact of selective logging. Fires play a significant role in the African carbon cycle, with 1.03 ± 0.22 Pg C yr −1 of carbon emissions, and 90 % originating in savannas and dry woodlands. A large portion of the wild fire emissions are compensated by CO 2 uptake during the growing season, but an uncertain fraction of the emission from wood harvested for domestic use is not. Most of these fluxes have large in-terannual variability, on the order of ±0.5 Pg C yr −1 in standard deviation, accounting for around 25 % of the year-to-year variation in the global carbon budget. Despite the high uncertainty, the estimates provided in this paper show the important role that Africa plays in the global carbon cycle, both in terms of absolute contribution, and as a key source of interannual variability.

GlobAllomeTree is an international platform for tree allometric equations. It is the first worldwide web platform designed to facilitate the access of the tree allometric equation and to facilitate the assessment of the tree biometric characteristics for commercial volume, bio-energy or carbon cycling. The webplatform presents a database containing tree allometric equations, a software called Fantallomatrik, to facilitate the comparison and selection of the equations, and documentation to facilitate the development of new tree allometric models, improve the evaluation of tree and forest resources and improve knowledge on tree allometric equations. In the Fantallometrik software, equations can be selected by country, ecological zones, input parameters, tree species, statistic parameters and outputs. The continuously updated database currently contains over 5000 tree allometric equations classified according to 73 fields. The software Fantallometrik can be also used to compare equations, insert new data and estimate the selected output variables using field inventory. The GlobAllomeTree products are freely available at the URL: http://globallometree.org for a range of users including foresters, project developers, scientist, student and government staff.

The African continent contributes one of the largest uncertainties to the global CO 2 budget, because very few long-term measurements are carried out in this region. The contribution of Africa to the global carbon cycle is characterized by its low fossil fuel emissions, a rapidly increasing population causing cropland expansion, and degradation and deforestation risk to extensive dryland and savannah ecosystems and to tropical forests in Central Africa. A synthesis of the carbon balance of African ecosystems is provided at different scales, including observations of land–atmosphere CO 2 flux and soil carbon and biomass carbon stocks. A review of the most recent estimates of the net long-term carbon balance of African ecosystems is provided, including losses from fire disturbance, based upon observations, giving a sink of the order of 0.2 Pg C yr −1 with a large uncertainty around this number. By comparison, fossil fuel emissions are only of the order of 0.2 Pg C yr −1 and land-use emissions are of the order of 0.24 Pg C yr −1 . The sources of year-to-year variations in the ecosystem carbon-balance are also discussed. Recommendations for the deployment of a coordinated carbon-monitoring system for African ecosystems are given.

This study gives an outlook on the carbon balance of Sub-Saharan Africa (SSA) by presenting a summary of currently available results from the project CarboAfrica (namely net ecosystem productivity and emissions from fires, deforestation and forest degradation, by field and model estimates) supplemented by bibliographic data and compared with a new synthesis of the data from national communications to UNFCCC. According to these preliminary estimates the biogenic carbon balance of SSA varies from 0.16 Pg C y−1 to a much higher sink of 1.00 Pg C y−1 (depending on the source data). Models estimates would give an unrealistic sink of 3.23 Pg C y−1, confirming their current inadequacy when applied to Africa. The carbon uptake by forests and savannas (0.34 and 1.89 Pg C y−1, respectively,) are the main contributors to the resulting sink. Fires (0.72 Pg C y−1) and deforestation (0.25 Pg C y−1) are the main contributors to the SSA carbon emissions, while the agricultural sector and forest degradation contributes only with 0.12 and 0.08 Pg C y−1, respectively. Savannas play a major role in shaping the SSA carbon balance, due to their large extension, their fire regime, and their strong interannual NEP variability, but they are also a major uncertainty in the overall budget. Even if fossil fuel emissions from SSA are relative low, they can be crucial in defining the sign of the overall SSA carbon balance by reducing the natural sink potential, especially in the future. This paper shows that Africa plays a key role in the global carbon cycle system and probably could have a potential for carbon sequestration higher than expected, even if still highly uncertain. Further investigations are needed, particularly to better address the role of savannas and tropical forests and to improve biogeochemical models. The CarboAfrica network of carbon measurements could provide future unique data sets for better estimating the African carbon balance.

Leaf gas exchange and plant water relations of three co-occurring evergreen Mediterranean shrubs species, Quercus ilex L. and Phillyrea latifolia L. (typical evergreen sclerophyllous shrubs) and Cistus incanus L. (a drought semi-deciduous shrub), were investigated in order to evaluate possible differences in their adaptive strategies, in particular with respect to drought stress. C. incanus showed the highest annual rate of net photosynthetic rate (PN) and stomatal conductance (gs) decreasing by 67 and 69 %, respectively, in summer. P. latifolia and Q. ilex showed lower annual maximum PN and gs, although PN was less lowered in summer (40 and 37 %, respectively). P. latifolia reached the lowest midday leaf water potential (Ψ1) during the drought period (-3.54±0.36 MPa), 11 % lower than in C. incanus and 19 % lower than in Q. ilex. Leaf relative water content (RWC) showed the same trend as Ψ1. C. incanus showed the lowest RWC values during the drought period (60 %) while they were never below 76 % in P. latifolia and Q. ilex; moreover C. incanus showed the lowest recovery of Ψ1 at sunset. Hence the studied species are well adapted to the prevailing environment in Mediterranean climate areas, but they show different adaptive strategies that may be useful for their co-occurrence in the same habitat. However, Q. ilex and P. latifolia by their water use strategy seem to be less sensitive to drought stress than C. incanus.

Structural traits of the vegetation types and plantations occurring in a protected area within the caldera of Vico Lake (Italy) were analysed. There were significant correlations among structural traits, at leaf and stand level. Leaf area index (LAI) and specific leaf area (SLA) were the most significantly correlated traits. LAI rose according to stand plant density, tree size and SLA; the highest LAI value monitored in the Fagus sylvatica L. forest was justified by the largest tree size (28.9±2.8 m height and 53±15 cm diameter) and the highest SLA (212±23 cm2 g-1). The main traits determining the variations in leaf structure among species were analysed by Principal Component Analysis (PCA). The LAI values were used to realise a map allowing us to delimit high LAI values (4.1–5.0), corresponding to the F. sylvatica forest and to the F. sylvatica forest with the sporadic presence of Quercus cerris L. and Castanea sativa Miller, mean LAI values (classes 3.1–4.0) corresponding to Corylus avellana L....

A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy-relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. In addition, uncertainties for each observation data-stream should be assessed. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases interoperable, and on the calibration of each component of the system to agreed-upon international scales., JRC.H.7-Climate Risk Management

The anatomical and morphological leaf traits as well as leaf inclination and orientation per different leaf age cohort of Quercus ilex , Phillyrea latifolia and Cistus incanus growing in the Mediterranean maquis along Rome’s coast-line (Italy) were investigated. Specific leaf weight (SLW), total leaf thickness ( L ), leaf density index and leaf inclination ( α ) changed according to leaf age. The maximum values were measured at full leaf expansion, underlining the strong influence of α on the reduction of solar radiation incident on leaf surface and the importance of the received solar radiation by leaf structure during leaf age. C. incanus summer leaves had the lowest surface area, the highest SLW (15±2 mg cm −2 ) and L (244±15 μm) with respect to winter leaves, reducing the evaporative leaf surface during drought. Older leaves of 2–4 years Q. ilex and P. latifolia , shaded by new leaves had lower α than 1 year old leaves. α is a linear function of SLW. By the seasonal leaf dimorphism and the characteristic leaf folding the adjustment of leaf inclination angle from −37° in winter leaves to +44° in summer leaves increased reduction of incident solar radiation during drought. Leaf folding may be related to the less xeromorphic leaf structure of C. incanus . The index of xeromorphism, measured at full leaf expansion and resulting from the surface area of the polygon plotted joining the value of the seven considered xeromorphic leaf traits in the radar graph, is the highest in P. latifolia (0.88), and the lowest in C. incanus (0.44).

There are significant differences in leaf life-span among evergreen sclerophyllous species and drought semideciduous species growing in the Mediterranean maquis. Cistus incamus, which has a leaf life-span of four-eight months, was characterised by the highest net photosynthetic rates (PN), while Quercus ilex and Phillyrea latifolia, which maintain their leaves two-three and two-four years, respectively, had a lower PN. The longer leaf life-span of the two evergreen sclerophyllous species may be justified to cover the high production costs of leaf protective structures such as cuticle, hairs, and sclereids: cuticle and hairs screen radiation penetrating into the more sensitive tissues, and sclereids have a light-guiding function. Q. ilex and P. latifolia have the highest leaf mass/area ratio (LMA = 209 g m-2) and a mesophyll leaf density (2065 cells per mm2 of leaf cross section area) about two times higher than C. incanus. In the typical evergreen sclerophyllous species the steepest leaf inclination (α = 56°) reduces 42 % of radiation absorption, resulting in a reduced physiological stress at leaf level, particularly in summer. C. incanus, because of its low leaf life-span, requires a lower leaf investment in leaf protective structures. It exhibits a drastic reduction of winter leaves just before summer drought, replacing them with smaller folded leaves. The lower leaf inclination (α = 44°) and the lower LMA (119 g m-2) of C. incanus complement photosynthetic performance. Water use efficiency (WUE) showed the same trend in Q. ilex, P. latifolia, and C. incanus, decreasing 60 % from spring to summer, due to the combined effects of decreased CO2 uptake and increased transpirational water loss.

Plant communities of the Mediterranean climate Regions are exposed to high temperatures, high radiation and water stress during summer; they are dominated by evergreen sclerophyllous species and drought semi deciduous species. To define the adaptive strategies, anatomical and morphological leaf traits of Quercus ilex L., Phillyrea latifolia L. (typical evergreen sclerophyllous species) and Cistus incanus L., (a drought semi deciduous species), growing in the Mediterranean maquis along Rome’s coast line (Italy) were analysed. The typical evergreen sclerophyllous species have long leaf life span (from 1 to 4 years), steeper leaf inclination (average 56°), higher specific leaf mass (average 21.3 mg cm-2) and the highest leaf thickness (average 324 μm). The semi deciduous species have a lower leaf life span (from 4 to 8 months), a lower leaf inclination (44°±13°), a lower specific leaf mass (14.7±1.5 mg cm2) and a lower leaf thickness (244±15 µn). The more xeromorphyc species (Q. ilex and P. latifolia) may be at a competitive advantage considering the forecasted air temperature increase in the Mediterranean basin. Increasing drought stress may in fact determine a shortening of leaf life span that may prove to be critical for C. incanus. Knowledge of plant response to stress factors is important in the perspective of climatic changes.

Vegetation phenology and its variability have substantial influence on land-atmosphere interaction, and changes in growing season length are additional indicators of climate change impacts on ecosystems. For these reasons, global land surface models are routinely evaluated in order to assess their ability to reproduce the observed phenological variability. In this work, we present a new approach that integrates a wider spectrum of growing season modes, in order to better describe the observed variability in vegetation growing season onset and offset, as well as assess the ability of state-of-the-art land surface models to capture this variability at the global scale. The method is applied to the Community Land Model version 4.5 (CLM4.5) simulations and LAI3g satellite observation. The comparison between data and model outputs shows that CLM4.5 is capable of reproducing the growing season features in the Northern Hemisphere midlatitude and high latitude, but also displays its limitations in areas where water availability acts as the main driver of vegetation phenological activity. Besides, the new approach allows evaluating land surface models in capturing multigrowing-season phenology. In this regard, CLM4.5 proves its ability in reproducing the two-growing-season cycles in the Horn of Africa. In general, the new methodology expands the area of analysis from northern midlatitude and high latitude to the global continental areas and allows to assess the vegetation response to the ongoing climate change in a larger variety of ecosystems, ranging from semiarid regions to rain forests, passing through temperate deciduous and boreal evergreen forests.

There is currently a lack of representative, systematic and harmonised greenhouse gas (GHG) observations covering the variety of natural and human-altered biomes that occur in Africa. This impedes the long-term assessment of the drivers of climate change, in addition to their impacts and feedback loops at the continental scale, but also limits our understanding of the contribution of the African continent to the global carbon (C) cycle. Given the current and projected transformation of socio-economic conditions in Africa (i.e. the increasing trend of urbanisation and population growth) and the adverse impacts of climate change, the development of a GHG research infrastructure (RI) is needed to support the design of suitable mitigation and adaptation strategies required to assure food, fuel, nutrition and economic security for the African population. This paper presents the initial results of the EU-African SEACRIFOG project, which aims to design a GHG observation RI for Africa. The first stages of this project included the identification and engagement of key stakeholders, the definition of the conceptual monitoring framework and an assessment of existing infrastructural capacity. Feedback from stakeholder sectors was obtained through three Stakeholder Consultation Workshops held in Kenya, Ghana and Zambia. Main concerns identified were data quality and accessibility, the need for capacity building and networking among the scientific community, and adaptation to climate change, which was confirmed to be a priority for Africa. This feedback in addition to input from experts in the atmospheric, terrestrial and oceanic thematic areas, facilitated the selection of a set of 'essential variables' that need to be measured in the future environmental RI. An inventory of 47 existing and planned networks across the continent allowed for an assessment of the current RIs needs and gaps in Africa. Overall, the development of a harmonised and standardised pan-African RI will serve to address the continent's primary societal and scientific challenges through a potential cross-domain synergy among existing and planned networks at regional, continental and global scales. (Less)