Patterns and processes of land systems

We investigated to what extent the analytical and empirical methods shown in chapters 2 to 4 can explain the complexity of land use systems in the Brazilian Amazon, regarding spatial- temporal patterns and processes occurring at different spatial scales. Insights on interactions and feedbacks occurring at/within different spatial scales were systematically taken from the

results of chapters 2, 3 and 4. Such insights came up from the holistic view of empirical statistical behavior of drivers, changing patterns and processes, and household level interviews to landholders of different farm sizes in Rondônia and Mato Grosso states (Soler, 2011; Soler et al., 2007). That allowed to gather sufficient information to identify interactions and associated feedbacks within specific coupled human-environmental systems. The term coupled human-environment system is used to acknowledge the fact that humans, as users, actors and managers are not external, but an integral elements of the studied system (Schröter et al., 2004). The importance of actor diversity on land change is also acknowledged by the explicit consideration of different farm types. This section is divided in two parts where I discuss: 1) Patterns and processes of land use/cover change at different spatial scales, and; 2) The links between land use intensification and land tenure issues.

6.3.1 Pattern-process description at different spatial scales

The outputs of chapter 3 indicated that household level data, when compared to remote sensing, spatial and/or census data, point to similar patterns of land cover change for Rondônia State, but also demonstrate some divergent land change processes across local and regional spatial scales. Census data, remote sensing and interviews with key informants during fieldwork in Rondônia and Mato Grosso indicate heterogeneous land cover change patterns and processes during the last decades. Each data source represents a slightly different reality.

In order to understand patterns and processes of land dynamics in the Brazilian Amazon we have to consider the heterogeneity of location factors and drivers of deforestation and secondary forest change, as well as the interactions among them that can act diversely across spatial scales. Indications of these interactions were provided during fieldwork campaigns and they were confirmed in distinct patterns and processes analyses of land cover/use change in chapters 2, 3 and 4. Particularly, the description of patterns and processes shows that: a) interactions at local and regional scales are similar regarding drivers of accessibility to infrastructure and indirect socioeconomic causes; b) biophysical variables (i.e. location factors) and policy aspects (i.e. underlying causes such as spatial zoning) tend to act differently between the spatial scales adopted.

In terms of location factors, the differences across scales are either due to the distinct level of influence of biophysical aspects to deforestation processes (e.g. soil fertility, soil types or geomorphology) better perceivable when confronting results within scales, or to the coarser level of spatial data compared to land use/cover patterns. In terms of policy aspects, their stronger influence at the regional scale are likely due to land use history and land distribution, which indirectly underpin the extent of fertile soils within small and larger farms. This output reveals that similar process over regional and local patterns of soil fertility influencing deforestation depending on land use history (i.e. the spatial zoning or aggregation of lots in older settlements). On the other hand, despite land use history and land distribution might act similarly within extents at local scale in Rondônia. Their influence on deforestation processes are very dissimilar at the regional scale compared to Rondônia and Mato Grosso states (further discussed in the next section).

These analyses indicate that empirical statistical descriptions with regression analysis are capable to identify similarities and divergences of patterns and processes across different spatial scales, a result also obtained for Central America (Kok, 2001). Despite this ability, these statistical methods cannot identify and explore interactions within location factors, drivers and processes that act across scales.

6.3.2 Land use intensification links to land distribution issues

It is generally understood that land use system investigation in the Brazilian Amazon must take into account land use intensification and the associated land tenure and land distribution issues (Alves, 2002; Fearnside, 1993; Vosti et al., 2002). In chapter 4, some of these underlying causes were tackled by investigating how processes acting at the household level (e.g. land distribution issues) act from local to broader scales throughout interactions with location factors (e.g. soil fertility) and drivers of land use change (e.g. infrastructure and accessibility based on roads).

The results in chapter 4 indicate that land distribution influences land use intensification processes in different ways in time and space in the Amazonian states of Rondônia and Mato Grosso. National and international demands for beef and soybean, accessibility to beef/milk markets and technological improvement through machinery as well as labor force concentration have contributed to land use intensification among medium to

large farms. The same processes have occurred among small farms, but instead they have been more driven by stocking rates, improvement of accessibility and demand to milk markets. Despite diverse, all interactions are connected to the fact that all farm size categories share the same natural resources, but the existing socioeconomic system provides distinct and usually unbalanced benefits between these categories of farm sizes. Such social and environmental issues among small farms also depend on land use systems that can succeed to sustainable alternative trajectories or fail due to land degradation. The lack of land management together with badly-driven investments can explain the failure of usual pasture after slash-and-burn land systems among small farms in less fertile spots. The influence of land speculation by large landholders seems also to be a determinant of such failure.

The analyses summarized in sections 6.2 and 6.3 lead to the conclusion that using regressions I was able to identify similarities and divergences of patterns and processes across different spatial scales. Nevertheless, associations between land use patterns and process of land cover change do not provide satisfactory comprehension of the identified coupled human-environmental systems. In other words, the interactions between human actions and the environment identified at different spatial scales in the Brazilian Amazon that might end up in relevant feedbacks cannot be explored using standard statistical methods. Thus, in the next section I discuss the outcomes of chapter 5 in which a simple system dynamics model is used to help describing and understanding feedback loops of decision-making processes. This understanding might contribute towards a more sustainable management of the human-environmental system.