Impacts of Agricultural Practices and Individual Life Characteristics on Ecosystem Services: A Case Study on Family Farmers in the Context of an Amazonian Pioneer Front

Ticks infesting terrestrial small mammals in a rural settlement in the Amazonas state, Brazil

There is limited knowledge about tick diversity in the Amazon region. Here, we survey small terrestrial mammals for tick infestation at the Rio Pardo settlement, Amazonas State, Brazil. Sampling included rainy and dry seasons and four ecotones (primary forest, forest in regeneration, field crops and households). Each animal was inspected for ticks, which, if present, were placed in 70% alcohol and identified. Parasitological indexes were calculated and the presence/absence of ticks on hosts was tested for possible associations with independent variables (ecotone, host sex, host order, host family, host age and season). A total of 208 small mammals were captured, 47 individuals (10 species) in the primary forest, 124 (15 species) in the forest in regeneration, 11 (7 species) in the field crops, and 26 (4 species) in the households. A total of 14 small mammals were infested by ticks (overall prevalence: 6.7%; 95% CI: 3.72 - 11.04%), which consisted of 51 specimens that were identified into four species, as follows: Amblyomma humerale (32 nymphs); Ixodes luciae (6 females); Amblyomma coelebs (1 nymph); and Ornithodoros mimon (1 larva). In addition, 11 larvae were retained as Amblyomma spp. Only host order showed association (P = 0.002) with tick infestation, with marsupials 5.5 times more infested than rodents. Our record of O. mimon on D. marsupialis is the first on this host species, and the first record of a Argasidae tick in the Brazilian state of Amazonas. To the best of our knowledge, this is the first study that actively screened free-living terrestrial small mammals and provided data on prevalence, mean intensity and mean abundance of tick infestations in the Brazilian Amazonas state.

The impact of global climate change on the number and replacement of provisioning ecosystem services of Brazilian Cerrado plants

It is essential to predict areas of losses or exchanges of ecosystem services to adapt communities to the impacts caused by climate change. Particularly for provisioning ecosystem services provided by economically important plant species, understanding the association between climate change impacts and deforestation of native vegetation increases the accuracy of those predictions. Thus, we aim to (i) map the richness of provisioning ecosystem services from economically important native plants; (ii) use forecasts (present and future) of the distribution of ecosystem services to assess areas of changes in the number and type of provisioning ecosystems services. We evaluated provisioning ecosystem services from 110 Cerrado native species of economic importance for the local population. We determined the potential distribution of these plants using ecological niche modeling techniques, which were grouped according to the 21 different services provided. The forecasts for variation in richness and type of service used four future climate change scenarios (RCPs 4.5 and 8.5 in 2050 and 2070). The service losses detected in our models were associated with variables representing the progress of native vegetation deforestation in the biome due to agricultural expansion. Currently, ecosystem services can be found simultaneously in practically the entire biome. However, changes in the global climate will impact the potential geographic distribution of those plants, causing many areas in the biome to have reduced availability of potential ecosystem services. Moreover, due to the association between exposure to climate change and deforestation of native vegetation, the northern region of the biome will likely have the distribution of ecosystem services severely affected.

Spatio-temporal variations and coupling of human activity intensity and ecosystem services based on the four-quadrant model on the Qinghai-Tibet Plateau

Human activities have an impact on the structure and function of ecosystems, which in turn affects ecosystem service (ES) supply and demand. Based on the four-quadrant model of human activities and ecosystem services, this study evaluated the ecological quality at the county scale on the Qinghai-Tibet Plateau (QTP). Results showed: (1) Human activity intensity (HAI) showed great spatio-temporal variations across the QTP. The mean HAI was low overall and increased by 4% during 2000-2015. HAI in more than 13% of the area of the QTP showed an increasing trend and high HAI levels were mainly distributed in the eastern and central parts. A low HAI level occupied the majority of the study area and declined during the period. (2) The mean ES balance declined during the period and exhibited great spatial variations, with the higher ES balance mainly distributed in the mid-eastern cities of the QTP. The ES balance in approximately 68% of the cities decreased, indicating the ESs were in degradation, with demand exceeding supply. (3) Approximately 98% of the study area, including 205 counties, was in the first, second and fourth quadrant, and only 2% was in the third quadrant, indicating that ecological quality became better overall on the QTP. During 2000-2015, 87.14% of counties were nearly unchangeable-these were distributed in the most regions of the QTP, and only 9.79% and 3.08% of counties were improving and degrading, respectively, mainly distributed in the mid-eastern regions. The change implied that the ecosystems were basically in a stable state and the environment greatly improved on the QTP from 2000 to 2015. This study contributes to exploring the effect of human activity on ecosystem service, thereby providing credible guidance for regional ecosystem management.