Economically important species dominate aboveground carbon storage in forests of southwestern Amazonia

Tree species in tropical forests provide economically important goods and ecosystem services. In submontane forests of southwestern Amazonia, we investigated the degree to which tree species important for subsistence and trade contribute to aboveground carbon storage (AGC). We used 41 1-hectare plots to determine the species abundance, basal area, and AGC of stems > 10 cm diameter at breast height (dbh). Economically important taxa were classified using ethnobotanical studies and according to their stem density. These taxa (n = 263) accounted for 45% of total stems, 53% of total basal area, and 56% of total AGC, significantly more than taxa with minor or unknown uses (Welch test at p 40 cm and few stems in regeneration classes of dbh < 10 to 20 cm (e.g., Bertholletia excelsa, Cariniana spp., Cedrelinga spp., Ceiba spp., Dipteryx spp.), whereas dominant Tetragastris spp., and Pseudolmedia spp. had most stems in low diameter classes and a median diameter of < 30 cm. Bertholletia excelsa, with 1.5 stems per hectare, showed the highest basal area of any species and accounted for 9% of AGC (11 Mg/ha), twice that of the second-ranking species. Our study shows that economic importance and carbon stocks in trees are closely linked in southwestern Amazonia. Unplanned harvests can disrupt synergistic dual roles altering carbon stocks temporally or permanently. Precautionary measures based on species ecology, demography, and regeneration traits should be at the forefront of REDD+ to reconcile maximum harvesting limits, biodiversity conservation, and sustainable forest management

Describing complex interactions of social-ecological systems for tipping point assessments: an analytical framework

Humans play an interconnecting role in social-ecological systems (SES), they are part of these systems and act as agents of their destruction and regulation. This study aims to provide an analytical framework, which combines the concept of SES with the concept of tipping dynamics. As a result, we propose an analytical framework describing relevant dynamics and feedbacks within SES based on two matrixes: the “tipping matrix” and the “cross-impact matrix.” We take the Southwestern Amazon as an example for tropical regions at large and apply the proposed analytical framework to identify key underlying sub-systems within the study region: the soil ecosystem, the household livelihood system, the regional social system, and the regional climate system, which are interconnected through a network of feedbacks. We consider these sub-systems as tipping elements (TE), which when put under stress, can cross a tipping point (TP), resulting in a qualitative and potentially irreversible change of the respective TE. By systematically assessing linkages and feedbacks within and between TEs, our proposed analytical framework can provide an entry point for empirically assessing tipping point dynamics such as “tipping cascades,” which means that the crossing of a TP in one TE may force the tipping of another TE. Policy implications: The proposed joint description of the structure and dynamics within and across SES in respect to characteristics of tipping point dynamics promotes a better understanding of human-nature interactions and critical linkages within regional SES that may be used for effectively informing and directing empirical tipping point assessments, monitoring or intervention purposes. Thereby, the framework can inform policy-making for enhancing the resilience of regional SES

Describing complex interactions of social-ecological systems for tipping point assessments: an analytical framework

Humans play an interconnecting role in social-ecological systems (SES), they are part of these systems and act as agents of their destruction and regulation. This study aims to provide an analytical framework, which combines the concept of SES with the concept of tipping dynamics. As a result, we propose an analytical framework describing relevant dynamics and feedbacks within SES based on two matrixes: the “tipping matrix” and the “cross-impact matrix.” We take the Southwestern Amazon as an example for tropical regions at large and apply the proposed analytical framework to identify key underlying sub-systems within the study region: the soil ecosystem, the household livelihood system, the regional social system, and the regional climate system, which are interconnected through a network of feedbacks. We consider these sub-systems as tipping elements (TE), which when put under stress, can cross a tipping point (TP), resulting in a qualitative and potentially irreversible change of the respective TE. By systematically assessing linkages and feedbacks within and between TEs, our proposed analytical framework can provide an entry point for empirically assessing tipping point dynamics such as “tipping cascades,” which means that the crossing of a TP in one TE may force the tipping of another TE. Policy implications: The proposed joint description of the structure and dynamics within and across SES in respect to characteristics of tipping point dynamics promotes a better understanding of human-nature interactions and critical linkages within regional SES that may be used for effectively informing and directing empirical tipping point assessments, monitoring or intervention purposes. Thereby, the framework can inform policy-making for enhancing the resilience of regional SES

Describing complex interactions of social-ecological systems for tipping point assessments: an analytical framework

Humans play an interconnecting role in social-ecological systems (SES), they are part of these systems and act as agents of their destruction and regulation. This study aims to provide an analytical framework, which combines the concept of SES with the concept of tipping dynamics. As a result, we propose an analytical framework describing relevant dynamics and feedbacks within SES based on two matrixes: the “tipping matrix” and the “cross-impact matrix.” We take the Southwestern Amazon as an example for tropical regions at large and apply the proposed analytical framework to identify key underlying sub-systems within the study region: the soil ecosystem, the household livelihood system, the regional social system, and the regional climate system, which are interconnected through a network of feedbacks. We consider these sub-systems as tipping elements (TE), which when put under stress, can cross a tipping point (TP), resulting in a qualitative and potentially irreversible change of the respective TE. By systematically assessing linkages and feedbacks within and between TEs, our proposed analytical framework can provide an entry point for empirically assessing tipping point dynamics such as “tipping cascades,” which means that the crossing of a TP in one TE may force the tipping of another TE. Policy implications: The proposed joint description of the structure and dynamics within and across SES in respect to characteristics of tipping point dynamics promotes a better understanding of human-nature interactions and critical linkages within regional SES that may be used for effectively informing and directing empirical tipping point assessments, monitoring or intervention purposes. Thereby, the framework can inform policy-making for enhancing the resilience of regional SES

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Leaves of pioneer and later-successional trees have similar lifetime carbon gain in tropical secondary forest

Different life history strategies among tropical rain forest species are generally related to inherent trade-offs in leaf and crown, traits, with early-successional species having traits that facilitate high productivity but a relatively wasteful use of resources and shadetolerant later-successional species exhibiting the opposite strategy. But the degree to which these trait differences contribute to short- and long-term carbon gain of different species that coexist in natural forest has not been quantitatively scaled. We applied a canopy model in combination with measurements of canopy structure, mass distribution, and leaf photosynthesis to determine whole-plant daily photosynthesis (Ppl) of individuals of three short-lived pioneers (SLP), four later-successional species, and three lianas growing together in a 0.5-, 2-, and 3-yr-old secondary tropical forest stand. Whole-plant daily photosynthesis per unit leaf mass (Plfm) and aboveground mass (P m) were assumed to indicate daily returns on investment at the leaf and crown level. By integrating these calculations with measured leaf longevities, we determined the lifetime carbon gain per unit leaf mass. Vegetation height and leaf area index increased with stand age. Two of the SLPs, Trema and Ochroma, increasingly dominated the top of the vegetation. In the 0.5-yr-old stand, these species also had the highest Pm and P lfm values. Whole-plant daily photosynthesis per unit leaf mass tended to decline with stand age but much more strongly so in the later-successional species than in the SLP. Leaf longevity was not significantly correlated with individual leaf traits (e.g., specific leaf area or leaf N content) but was strongly and negatively correlated with Plfm in the youngest stand. Latersuccessional species had considerably greater leaf longevities than SLP. Lifetime carbon gain per unit leaf mass, however, was relatively similar between the different species. Thus due to the strong negative correlation that exists between daily leaf productivity (P lfm) and longevity, short-lived pioneers and later-successional species achieve similar lifetime carbon gain per unit leaf mass in natural secondary forest. This could help explain why the slower-growing latersuccessional species are able to persist during the first years of succession.</p

Appendix A. Mean height, patterns of biomass allocation, leaf area, and light interception per species in each of the three successional stands as well the results Sidak pairwise comparisons between species within stands.

Mean height, patterns of biomass allocation, leaf area, and light interception per species in each of the three successional stands as well the results Sidak pairwise comparisons between species within stands