The critically endangered Brazilian pine, also called araucaria, (Araucaria angustifolia (Bertol.) Kuntze) is a key species of the Araucaria moist forest (AMF, Mixed Ombrophilous Forest). Illegal timber extraction, agricultural conversion and severe degradation have reduced the AMF to only 13 per cent of its original cover, with climate change imposing additional challenges for cold adapted species such as araucaria. Previous studies have assessed climate change impacts on A. angustifolia, but have been limited by analysis constraints. Here, we used a machine learning technique to understand how land use and climate change might affect the distribution of A. angustifolia, and to evaluate the effectiveness of existing protected areas (PAs) to conserve this species. Our results demonstrated that despite the recent efforts to conserve the Atlantic Forest, conversion of natural habitats into forest plantation still occurs within araucaria’s distribution range. Our model predicted a drastic reduction in environmentally suitable areas for this species of up to 77 per cent in the coming decades. Also, the existing PAs show low efficacy to protect suitable areas in the future. Combined, these results suggest that A. angustifolia will be under great threat within the next few decades and the development of conservation strategies to save this species is essential. Ideally, the conservation programs should integrate in situ and on farm approaches, including forest management strategies. Although in situ strategies play an important role as gene banks, on-farm strategies can be used to promote the restoration and expansion of A. angustifolia populations in the areas predicted as suitable.

This study aimed to understand post-agricultural natural forest regeneration in the Southern Brazilian Atlantic Forest and its possible role as a cost-effective, passive approach to forest restoration. The study characterized vegetation structure, floristic composition, and the dynamics of secondary forest chronosequences. Data were collected from 159 plots (10 × 10 m each) across forest remnants in Santa Catarina State, covering forest ages that ranged from 2 to 60 years of regeneration after swidden agriculture. Only areas with no signs of degradation were sampled in order to provide a description of vegetation characteristics that could be used to identify and monitor natural regeneration. A total of 11,455 woody plants were identified and classified into 334 species representing 71 families. As the succession process unfolds, the continuous turnover of species makes forests more diverse and structurally complex. Floristic similarity among forest types is observed during the early stages of succession, but decreases over time. Pioneer species dominate young secondary forests, representing about 40% of the basal area up to 10 years of regeneration. Shade-tolerant species start colonizing the sites at early ages; however, they become more important structural elements only after 30 years of succession. The observed patterns of forest structure and species diversity largely conform to the post-agricultural succession seen in many tropical forests. The high species diversity found in this study highlights the importance of natural regeneration as a strategy to restore ecosystems. Floristic data can be used as a reference for choosing suitable species for active restoration, as well as contributing to the design of integrated restoration strategies. We herein reinforce the potential of natural regeneration as part of large-scale restoration programs, which would be particularly attractive to family farmers by the low cost of supplies and labor.

(1) Brazil has great potential to expand the area under agroforestry, and thereby simultaneously enhance multiple ecosystem services. However, divergent interests are currently polarized between drastic environmental deregulation and public resource allocation to chemical-intensive land use versus conservation and sustainable agriculture. This highlights an urgent need for a comprehensive overview of the evidence of the benefits to society generated by agroforestry across Brazil. (2) We present a systematic map of the scientific evidence related to the effects of agroforestry on ecosystem services in Brazil. (3) Reviewing 158 peer-reviewed articles, published in international scientific journals (database: Web of Science), we identified a disproportionate emphasis on the Atlantic Forest. Very little research has been published on the Cerrado savanna, Pampa grasslands and Pantanal wetlands. Regulating services were much more frequently studied (85%) than provisioning (13%), while cultural services represent a major gap. A consistent positive effect of agroforestry was demonstrated for soil quality, habitat and food provisioning. Trade-offs were demonstrated for soils and habitats. (4) Our analysis identifies high-priority gaps given their critical importance for human well-being which should be filled: agroforestry effects on water provision and regulation. Moreover, they should assess other ES such as erosion control, flood protection and pest control to enable a more reliable inference about trade-offs.

Acca sellowiana (Berg) Burret is a predominantly allogamous species with hermaphrodite flowers that has barriers to self-fertilisation such as dichogamy by protogyny and self-incompatibility. This study aimed to identify when self-incompatibility occurs in A. sellowiana flowers submitted to self-pollinations. Pollinations were made using nine known self-incompatible accessions in several treatments including manual cross-pollination, manual self-pollination, no pollination and natural pollination. Flowers were pollinated and pistils collected at times ranging from 1 to 30 days after pollination (DAP). In both cross- and self-pollinations the fertilisation occurred from 18 DAP and the zygote was visualised at 24 and 26 DAP, respectively. The abscission of the self-pollinated flowers increased from 26 DAP onwards, when significant differences (P < 0.05) were found for the percentage of abscission among self-pollinated and cross-pollinated flowers. At 30 DAP, 72% of self-pollinated flowers were abscised. The size of ovules and ovaries of self-pollinated flowers showed no significant difference from those of non-pollinated flowers throughout 30 DAP, while those from cross-pollinated flowers were significantly larger (P < 0.05) than the other treatments from 22 and 24 DAP, respectively. After 40 DAP, there was no fruit development in self-pollination and non-pollination treatments. Our study brings greater clarity to the mechanism of self-incompatibility in A. sellowiana, indicating late-acting self-incompatibility occurring through the rejection/abscission of self-pollinated flowers precisely after syngamy and zygote formation.