Sustainable agro-pastoral systems:

concepts, approaches and tools

27 Marzo 2012

CNR - Sala Convegni

Via E. Bassini 15 - Milano

Giornata conclusiva del progetto congiunto del CNR-IMATI di Milano, del Dipartimento di Protezione dei Sistemi Agroalimentare e Urbano a Valorizzazione della Biodiversità dell'Università di Milano e di YEHA Natural Resource Management Institute di Addis Abeba, dal titolo "Strategie di gestione sostenibile dei sistemi agro-pastorali in Africa Sub-Sahariana", cofinanziato dal Comune di Milano.  
Responsabile scientifico del progetto: Dr. Sara Pasquali.

Il convegno è rivolto a studiosi di vari settori. La prima parte riguarderà tematiche agrarie e includerà presentazioni su argomenti inerenti i sistemi agro-pastorali e la gestione dei pascoli, con particolare attenzione al problema della sostenibilità.
La seconda parte avrà invece carattere matematico-economico: saranno illustrati modelli multitrofici e problemi di controllo ottimo con applicazioni nell'ambito delle risorse idriche, dei sistemi epidemiologici e dei sistemi agro-pastorali.

Hanno confermato la loro partecipazione

Bruno Buonomo
Giuseppe Buffoni
Alessandra Buratto
Michele Corti              
Gianni Gilioli
Maria Groppi
Università di Napoli
Università di Padova

Università di Milano
Università di Brescia
Università di Parma

E' previsto uno spazio per interventi brevi. Gli interessati possono proporre una presentazione inviando un  abstract all'indirizzo mail sara_AT_mi.imati.cnr.it entro il 16 marzo 2012.

La partecipazione al convegno è gratuita. Per motivi organizzativi, si prega di confermare la partecipazione inviando una mail allo stesso indirizzo entro il 16 marzo 2012.

Comitato Scientifico




10.10 - 10.40 HIWOT DESTA WODAJO (Università di Milano) An overview on overgrazing in Ethiopia
10.40 - 10.55 SILVANA MATTIELLO (Università di Milano) Project “Defence and valorization of biodiversity in Niger by means of environmental education programmes and opertative strategies”: state of the art and preliminary results
10.55 - 11.20 COFFEE BREAK
11.20 - 11.50 MICHELE CORTI (Università di Milano) Rangeland systems and agrofood sustainability
11.50 - 12.20 GIANNI GILIOLI (Università di Brescia) Agro-pastoral system sustainability: the social-ecological perspective
12.20 - 12.50 LUIGI MARIANI, SIMONE PARISI  (Università di Milano) Simulation of grazed grassland producitvity in Ethiopian Highlands (I parte)
Simulation of grazed grassland producitvity in Ethiopian Highlands (II parte)


14.30 - 15.00 ALESSANDRA BURATTO (Università di Padova) Optimal control theory for a sustainable management of an interconnected drinking water system
15.00 - 15.30 GIUSEPPE BUFFONI (CNR-IMATI) On biomass balance equations of a trophic chain: formulation and primary analysis
15.30 - 15.50 LUCA GALBUSERA (CNR-IMATI) Stability analysis and optimal control for an agro-pastoral system
15.50 - 16.10 COFFEE BREAK
16.10 - 16.40 MARIA GROPPI (Università di Parma) Optimal control of culling in epidemic models for wildlife
16.40 - 17.10 BRUNO BUONOMO (Università di Napoli) Mathematical approaches to infectious diseases control
17.10 - 17.25 PIETRO ALESSANDRO BRIVIO (CNR-IREA) Analysis of time series satellite imagery to monitor vegetated ecosystem dynamics in Sahel



GETACHEW TIKUBET  -  YEHA Natural Resource Management Institute di Addis Abeba

Sustainable livelihood using the integrated bioeconomy system


HIWOT DESTA WODAJO  -  Università di Milano

An overview on overgrazing in Ethiopia

Degradation of arable lands became the major constraint of production in East African highlands; Ethiopia is believed to be one of the Sub-Saharan African countries most seriously affected by land degradation. In Ethiopia an estimate 17% of the potential annual agricultural GDP of the country is lost because of physical and biological soil degradation. Causes for land degradation are: human population growth, poor soil management, overgrazing, deforestation, variation of climatic conditions, and intrinsic characteristics of fragile soils in diverse agro ecological zones. Ethiopia has the largest livestock population with Cattle population of 50.8 million, 25.9 million sheep, 21.9 million goat, 0.8 million camel, 1.9 million horses, 5 million donkeys, 0.3 million mules and total poultry population of 42 million; the largest in Africa. Livestock feed sources in Ethiopia, ruminants and equines are mainly (80-85%) natural grazing. Livestock density and grazing patterns lead to overgrazing, which is one of the major causes of land degradation. Overgrazing is much more severe in the highlands compared to the lowland areas. Among possible measures to prevent over grazing is to reduce number of animal and improve genetic potential of indigenous livestock, reduce livestock diseases; improve adequate feed supplies and animal nutrition. Introducing grazing management systems like controlled grazing and Zero grazing is another means of preventing over grazing. 


SILVANA MATTIELLO  -  Università di Milano

Project "Defence and valorization of biodiversity in Niger by means of environmental education programmes and operative strategies": state of the art and preliminary results

The project, supported by Comune di Milano, started on April 1st, 2011 and it is still in progress. It is supervised by the Dipartimento di Scienze Animali dell’Università degli Studi di Milano, in collaboration with the Italian ONG “Terre Solidali” and with the Niger Park Direction. The specific aim of the project is the valorization of biodiversity in the transition area of the Biosphere Reserve of Park W (at the border between Niger, Benin and Burkina Faso), through the reinforcement of the ability of the actors (Park guards, local communities, farmers, etc.) involved in biodiversity conservation and set up of operative strategies of natural resources.

The following activities have already been carried out: a) formation of Park rangers for correct spread of information about biodiversity management and environmental education; b) contribution to the preparation of a Visitor Centre in the W Park; c) production of informative material; d) monitoring wild-domestic animal spatial and sanitary interactions in areas within and around Pak W, using GIS technologies and parasite analysis. We set up a specific database, able to catalogue and geo-reference all spatial and sanitary information collected, and to graphically display them selecting the portions of information required. Using this tool, preliminary analysis of these data are currently being carried out.

At the moment, we are carrying out the following further activities: a) formation of farmers about animal health issues, on the basis of the results gathered in the first phase of the project; b) educational programmes on environmental protection for children in school age in the villages of the area around the W Park.


MICHELE CORTI  -  Università di Milano

Rangeland systems and agrofood sustainability


GIANNI GILIOLI  -  Università di Brescia

Agro-pastoral system sustainability: the social-ecological perspective


LUIGI MARIANI, SIMONE PARISI  -  Università di Milano

Simulation of grazed grassland producitvity in Ethiopian Highlands

This study is devoted to the simulation of vegetation biomass in a site of the Ethiopian highlands. Highlands are the main livestock grazing area of the Ethiopia and they are characterized by a monsoon climate  with mild daily temperatures and precipitation mainly centered on the June-September period.
In such conditions the main limitations to grasslands production are represented by soil water shortage and nutrients limitation. Sim_PP is the mathematical tool adopted to describe such grassland system, a mechanistic model which simulates the cascade of matter triggered by solar  energy.
Sim_PP is a dynamic model with a basic daily time step and an hourly fast loop adopted to describe temperature limitation. Gross ASSimilation (GASS) values coming from photosynthesis process are simulated with Goudrian and van Laar approach (1993). Main limitations due to relocation, maintenance respiration, conversion to final dry matter, temperature,  water stress and nutrient stress are also simulated adopting mechanistic or semi-empirical approaches. In the same way it is also approached the senescence process of grassland which gives strong limitation to nutrient value of grasses for livestock. A model run has been performed on the Addis Abeba airport meteorological time series, providing productivity data compatible with literature ones. Besides water limitation,  a crucial restriction is represented by Nitrogen shortage. As a matter of fact potential biomass production might be much higher  if plant nutrition could be satisfied, which represents an agronomic challenge for the future.


ALESSANDRA BURATTO  -  Università di Padova

Optimal control theory for a sustainable management of an interconnected drinking water system

The Optimal Control Theory is a branch of Optimization Theory that permits to tackle a wide variety of problems in different contexts. In particular its application to environmental problems is quite useful and many research lines deal with it.
In the following we formulate and solve a multi period optimal control model in order to determine the optimal abstraction policy for a provider of water services who has invested in the interconnection of two different sources (e.g. groundwater vs river abstraction) and wants to maximise his profit and to minimise the environmental costs related to the abstraction. The interconnection of water abstraction plants gives the provider the option to strategically decide the optimal mix of different water sources to be used in supplying water to a local community.



On biomass balance equations of a trophic chain: formulation and primary analysis

The basic assumptions for a paradigmatic ecosystem are stated. The biomass balance equations are formulated in terms of state variables representing the biomass density (kg/m²) of the following trophic levels: plant resources for herbivores, plant resources for herbiovores-carnivores, herbivores, herbivores-carnivores.
Then, the properties of the growth and trophic functions are illustrated, and an existence-stability analysis of the equilibrium states is performed for special dynamics models. Moreover, some results of numerical simulations are presented.



Stability analysis and optimal control for an agro-pastoral system

This contribution addresses topics related to the stability analysis and optimal resource management in tritrophic systems, namely ecosystems structured in three levels: resource (plants), bottom (herbivores) and top level predators (humans). In our model, the resource is assumed to be partitioned, so that the harvesting activities from the two classes of predators are kept distinct.
We analyze the proposed tritrophic food chain in order to assess the stability properties of the equilibria associated to the system as a function of the web structure and properties. Based on these observations, we study how to regulate human interactions with the lower levels, especially in order to achieve sustainability properties in managed ecosystems. To this end, tools from the optimal control theory will be applied in order to determine the optimal resource consumption by humans maximizing a societal objective function. Our management policy exploits three control variables: the human demand of plants, the human demand of herbivores and the human biomass consumption connected to adaptation processes not directly related to growth.
Finally, an application to an agro-pastoral systems in Sub-Saharan Africa is also considered, showing how our optimization-based methods can enhance the quality of resource exploitation by human communities in fragile ecosystems.


MARIA GROPPI  -  Università di Parma

Optimal control of culling in epidemic models for wildlife

Optimal control theory is applied to a system of ODEs modeling infectious diseases in wildlife. Culling is introduced as a strategy to eradicate the infection, and plays the role of control variable. The optimization criterion is to minimize both the number of infected animals and the cost of culling effort. Different forms of the objective cost function are considered, including quadratic control and linear control, and in the latter case the possibility of singular control is investigated. The optimality systems are solved numerically and results illustrate which is the optimal strategy in different scenarios, depending on the virulence of the disease. 


BRUNO BUONOMO  -  Università di Napoli

Mathematical approaches to infectious diseases control 

Infectious diseases are a leading cause of death worldwide, and the  south of the world is the most affected part. Therefore reducing the  disease burden means also reduce the gap between north and south of  the world. In this direction, mathematics can help to understand and  describe the mechanisms of spread of infectious diseases. In this talk  we will mention two useful mathematical approaches: the bifurcation  theory and the optimal control theory. In particular, based on two  recent papers [1,2], we focus on  vaccination strategies to fight   vertically transmitted diseases in both the cases of constant and  periodically transmitted diseases. Theoretical scenarios, analytical  results and computer simulations are  provided. The findings are used  to simulate simple scenarios for some real cases.
[1] B. Buonomo: On the optimal vaccination strategies for horizontally  and vertically transmitted infectious diseases. Journal of Biological  Systems, 19, n.2, 263-279 (2011)
[2] B. Buonomo: A simple analysis of vaccination strategies for  rubella. Mathematical Biosciences and Engineering, 8, n.3: 677-687  (2011)



Analysis of time series satellite imagery to monitor vegetated ecosystem dynamics in Sahel 

Recent studies on Sahel have shown an overall greening which demonstrates the recovery of these areas with respect to the strong drought of the ‘60s. Despite a recovery of the vegetation compound in those areas, several humanitarian crises, which are related to natural resources, have been reported in the region during the last decade. Further studies are needed to address different aspect of ecosystem dynamics in order to highlight anomalous changes that might cause possible critical situations. The present research aims to contribute to the understanding of climate/human impact on the status of pasture vegetation and agriculture in the Sahelian region from the late 90s to current days.
The dynamics of vegetated ecosystems in the region have been analyzed using time series of SPOT VGT 1-Km NDVI data and FEWS 8 km satellite RFE (Rainfall Estimate) in order to detect anomalous hot spots. High resolution Landsat TM data have been also used to interpret the results. Each dataset has been processed to derive “anomalies relative to mean” in order to make comparable the trends of the two different variables (rainfall and proxy of vegetation production).
This research was conducted as a part of the GEOLAND-2 project, a Collaborative Project (2008-2012) funded by the European Union under the 7th FP (project number
 218795), http://www.gmes-geoland.info/.