Socio-ecological costs of Amazon nut and timber production at community household forests in the Bolivian Amazon

Abstract

The Bolivian Amazon holds a complex configuration of people and forested landscapes in which communities hold secure tenure rights over a rich ecosystem offering a range of livelihood income opportunities. A large share of this income is derived from Amazon nut (Bertholletia excelsa). Many communities also have long-standing experience with community timber management plans. However, livelihood needs and desires for better living conditions may continue to place these resources under considerable stress as income needs and opportunities intensify and diversify. We aim to identify the socioeconomic and biophysical factors determining the income from forests, husbandry, off-farm and two keystone forest products (i.e., Amazon nut and timber) in the Bolivian Amazon region. We used structural equation modelling tools to account for the complex inter-relationships between socioeconomic and biophysical factors in predicting each source of income. The potential exists to increase incomes from existing livelihood activities in ways that reduce dependency upon forest resources. For example, changes in off-farm income sources can act to increase or decrease forest incomes. Market accessibility, social, financial, and natural and physical assets determined the amount of income community households could derive from Amazon nut and timber. Factors related to community households' local ecological knowledge, such as the number of non-timber forest products harvested and the number of management practices applied to enhance Amazon nut production, defined the amount of income these households could derive from Amazon nut and timber, respectively. The (inter) relationships found among socioeconomic and biophysical factors over income shed light on ways to improve forest-dependent livelihoods in the Bolivian Amazon. We believe that our analysis could be applicable to other contexts throughout the tropics as well.

Fig 1. Conceptual framework showing the potential relationships of socioeconomic (i.e., social assets, local ecological knowledge, financial assets) and biophysical attributes (i.e., market accessibility, natural and physical assets) in relation to household income.

Attributes can have direct and indirect effects on the response variable. An example of these relationships is included within parentheses in each attribute box. This conceptual framework is further developed for timber and Amazon nut income in the Supporting Information. Other variables used to characterize the different attributes are listed in Table 2.

Fig 2. Study site and location of research transects within a community household in the Bolivian Amazon.

Image from sentinel 2 satellite (band combination 11/8/2) acquired on August 25, 2016.

Fig 3. Income of community-based households from different sources by type of income (S) subsistence and (C) cash in the Bolivian Amazon.

The upper and lower quartiles in the boxplots explain 25% of the variation in the median net income derived by participating households. Empty circles are the outliers. CTMP = Community timber management plan, NTFPs = Non-timber forest products.

Fig 4. Contribution from forest (timber, Amazon nut, other NTFPs and hunting), husbandry (agriculture, agroforestry and livestock) and off-farm income (salary, business and gifts) incomes to the total net income of community households in the Bolivian Amazon by type of income: (S) subsistence and (C) cash.

The upper and lower quartiles in the boxplots explain 25% of the variation in the median net income derived by participating households. Empty circles are the outliers.

Fig 5. Socioeconomic and biophysical factors determining forest (timber, Amazon nut, other NTFPs and hunting) income of community households in the Bolivian Amazon.

Solid arrows indicate significant effects of a variable on another, whereas, dotted arrows indicate non-significant effects. Standardized coefficient values are at the intersection of the arrows indicating the direction of the relationships. Values are only provided for significant relationships that resulted from the structural equation (SEM) models.

Fig 6. Socioeconomic and biophysical factors determining income derived from husbandry (agriculture, agroforestry and livestock) by community households in the Bolivian Amazon.

Solid arrows indicate significant effects of a variable on another, whereas, dotted arrows indicate non-significant effects. Standardized coefficient values are at the intersection of the arrows indicating the direction of the relationships. Values are only provided for significant relationships that resulted from the structural equation (SEM) models.

Fig 7. Socioeconomic and biophysical factors determining off-farm (salary, business and gifts) income of community households in the Bolivian Amazon.

Solid arrows indicate significant effects of a variable on another, whereas, dotted arrows indicate non-significant effects. Standardized coefficient values are at the intersection of the arrows indicating the direction of the relationships. Values are only provided for significant relationships that resulted from the structural equation (SEM) models.

Fig 8

Socioeconomic and biophysical factors determining the income derived from (a) Amazon nut and (b) timber by community households in the Bolivian Amazon. Solid arrows indicate significant effects of a variable on another, whereas, dotted arrows indicate non-significant effects. Standardized coefficient values are at the intersection of the arrows indicating the direction of the relationships. Values are only provided for significant relationships that resulted from the structural equation (SEM) models.