Divergent responses of plant reproductive strategies to chronic anthropogenic disturbance and aridity in the Caatinga dry forest

• Published in: The Science of the total environment 2020-02, Vol.704, p.135240, Article 135240
• Main Authors: Silva, Jéssica Luiza S., Cruz-Neto, Oswaldo, Rito, Kátia F., Arnan, Xavier, Leal, Inara R., Peres, Carlos A., Tabarelli, Marcelo, Valentina Lopes, Ariadna
• Format: Article
• Language: English
• Subjects: Brazil; Climate Change; Ecosystem; Floral traits; Forestry; Forests; Fruits type; Functional diversity; Herbivory; Plants; Pollination; Reproductive biology; SDTF
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.135240

[Display omitted] •Disturbance and aridity affect Caatinga plant reproductive traits in different ways.•Aridity/disturbance reduced the richness of specialist pollination in the Caatinga.•Increases in aridity reduced the richness of animal-dispersed plants in the Caatinga.•Chronic anthropogenic disturbance affects the reproductive functional diversity.•Chronic anthropogenic disturbance and aridity threaten plant-animal interactions. Anthropogenic disturbance and climate change are major threats to biodiversity persistence and functioning of many tropical ecosystems. Although increases in the intensity of anthropogenic disturbance and climate change are associated with reduced taxonomic, phylogenetic and functional diversities of several organisms, little is known about how such pressures interfere with the distribution of plant reproductive traits in seasonally dry tropical forests. Here we test the hypothesis that individual and combined effects of increasing chronic anthropogenic disturbance and water deficit negatively affect the richness, abundance and diversity of specialized reproductive strategies of native woody plants in the Caatinga dry forest. This study was carried out at the Catimbau National Park, northeastern Brazil (62,294 ha). Chronic anthropogenic disturbance intensity was measured through different sources of disturbance (cattle/goat herbivory, wood extraction, and other people pressures). Water deficit data was obtained from hydrological maps and used as a proxy of aridity. We constructed generalized linear models and selected best-supported models for richness, abundance and functional diversity of reproductive traits. We documented that richness and abundance of plants with certain reproductive traits, regardless the specialization, can increase (in 18 out of the 49 trait categories analyzed; e.g. obligatory cross-pollination in response to increases in aridity and wood extraction), be impaired (in 20 categories; e.g. pollination by Sphingids/beetles with increase in aridity), or remain unchanged (in 21 categories; e.g. pollination by vertebrates with increases in chronic anthropogenic disturbance and aridity) with higher disturbance and aridity. There were combined effects of chronic anthropogenic disturbance and aridity on the richness of plants in nine traits (e.g. pollen flowers; dioecious and self-incompatible plants). Aridity affected 40% of the reproductive traits, while chronic anthropogenic disturbance affected 35.5%. The fun