Modelling Agrarian and Population Dynamics in the Philippines (MAPDIP)

(FNRS) FRFC Project, PI Nicolas Dendoncker (Geography, UNamur), Sabine Henry (Geography, UNamur) & Marjolein Visser (Bioingenieur, ULB)

The goals of the research

This project seeks to gain a broad understanding of the current dynamics of deforestation and farming practices in selected areas of the Pantaron range in Mindanao (Phillipines) that experience important population changes. The main objective is to understand the interactions between population dynamics, including the different migration waves, and the dynamics of the various farming systems in the area. The specific aims of the projects are fourfold:

To understand the population dynamics in place in the study area. We will seek to answer questions such as: ‘what are the migration rates in and out of the study area? How different are the demographical characteristics of newly arrived migrants, formerly arrived migrants and indigenous populations (IPs)?  

To understand the dynamics of the farming systems implemented after deforestation.  

To unfold the interactions between population and the environment in the study area. Specific questions will be asked: what are the differences between farming systems implemented by IPs, newly and formerly arrived migrants? Do various mixing patterns of these populations within a community lead to different farming systems?  

Finally, the project will suggest pathways to achieve sustainable farming systems at equilibrium with population dynamics. These systems will be described by the Ecosystem Services (ES) they provide.

In order to achieve these objectives, an agent-based modelling (ABM) framework will be developed, in which the interactions between local communities (both migrant and indigenous) and other relevant institutional stakeholders, and between these communities and their environment will be modelled explicitly, allowing for potentially conflicting objectives to be taken into account, and suitable solutions proposed. Scenarios or « what-if » situations of plausible land use futures will be co-developed with local stakeholders, depending on several migration and natural growths scenarios. The ultimate aim is to propose more productive and sustainable farming practices that are compatible with both the local biophysical and social contexts. In sum, the project aims at improving the theoretical understanding of the interactions between demographical (migration) and agricultural dynamics, using ABM as a powerful tool to unravel the complexities of these socio-ecological systems. More details on how these objectives will be achieved are given in the following sections.  

The state of the art

This section will start by presenting a brief description of the context in which the study takes place. It will then present a brief state of the art of the various subject areas the project deals with; i.e. the interactions between migration and the environment, how these interactions are integrated into participatory agent-based modelling of sustainable agricultural management, and finally, indicators of ecosystems services in prospective analysis of land use change (LUC).

Deforestation, migration and agricultural management in Mindanao, the Philippines

Forest cover in the Philippines has decreased from about 90% of the total land area before the Spanish colonization to 17-18 % in 2007 (Suarez and Sajise, 2010). Deforestation occurred throughout the country but substantial areas of forested land remain in Mindanao, notably in the Pantaron range (central Mindanao) where this study will be based. Additional reasons for choosing this area include 1) the partnership with ESSC; 2) the potential synergies with the PIC-CUD project (cf. section 1); and 3) The fact that it is a highly threatened biodiversity hotspot. Indeed, these areas as well as their indigenous communities experience high pressure from large agri-businesses and migrants’ communities coming from elsewhere in the country in search of new land to farm. Swidden agriculture is practiced in the uplands: forests are cut, burnt at the beginning of the dry season (late April, early May) and a poly-culture of commercial crops is implemented1. These crops are sold on national markets2. These processes result in a typical displacement of the deforestation front further upland towards the water divide. Additionally indigenous populations are also pushed further upland, sometimes to the altitude of mossy forests ecosystems where their traditional food systems, largely based on swidden agriculture combined with some gathering of berries and hunting, are threatened. However, some IPs remain in their original settlements and mix with migrant communities, which may influence their traditional cultivation practices in a way that can be detrimental to the environment (e.g. maize can be grown on steep slopes hence creating erosion) but positive influences may also exist. This will need to be clarified in the project. 

The impacts of migration on land use change

Significant research on the impacts of population and migration on LUC has been carried out in recent years (see e.g. review of Geist and Lambin (2001)). The focus of this research has largely been on identifying key drivers of change. A commonly cited key driver is the migration to the forest frontier of migrant colonists, especially smallholder agriculturalists (see e.g. Lambin et al. (2001) for a review). Studies on Asia find large impacts of migrants on forest cover. However, most of this research merely correlates the loss of forest cover with total population size or change (Bilsborrow, 2009). More research is needed to try to directly relate migration to LUC and deforestation. For example, the sources of spontaneous frontier migration and the factors pushing people to migrate from those origin areas to the frontier have received almost no attention in the literature (Bilsborrow, 2009). Additional research should try to disentangle the impacts on LUC of newly arrived vs. formerly arrived migrants and of the interactions between migrant and indigenous population. This project aims to do this through improved modelling.   

Participatory ABM of sustainable agriculture, including migration and a changing population

ABM of LUC are powerful tools to study land managers’ decision making, their interactions with each other and with their environments using sets of rules (see e.g. Matthews et al. 2007). Participatory ABM involve the participation of local actors and stakeholders at various stages in the modelling process. There have been numerous applications in the field of sustainable land use and resource management (e.g. Barnaud et al. (2008), and Campo et al. (2009) which both implement the companion modelling approach (collectif ComMod 2006)). Whilst these studies have achieved important methodological advances and practical results, it has to be noted that, even though some engage in prospective analysis through scenario modelling (e.g. Castella and Verburg 2007), none of these studies explicitly deal with demographic changes through e.g. variable migration rates, changes in mortality and fecundity rates. Wilson (2005) argues that little research on quantitative migration has been concerned with migration projection, instead focusing on describing and explaining the migration levels and patterns of the recent past. Wilson (2005) further states that the handling of migration in population projection models is conventionally carried out using simple models (with the exception of Wu et al., (2008)). As claimed by Booth (2006), ABM have the potential to assist in the development of demographic behavioural theory.  

Indicators of Ecosystem Services (ES)

Few studies have used ES in prospective analysis of LUC. Traditionally, the impact of LUC has been explored for individual ES, ignoring potential trade-offs between the provision of different services  (Murray-Rust et al. under review). Rounsevell et al. (2010) propose a new conceptual framework to assess the effects of environmental change on ecosystem services (the Framework for Ecosystem Services Provision, FESP). An important aspect of this framework is that it distinguishes between ES beneficiaries and ES providers. Formal recognition of ES beneficiaries is an important part of ecosystem assessments that integrate the role of people in shaping and benefiting from the natural world (Rounsevell et al, 2010). Generally speaking, there is a lack of applications that use ES to assess the resilience of agricultural systems in Southern countries.

 

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