Higher frequency of legitimate pollinators and fruit set of autotetraploid trees of Libidibia ferrea (Leguminosae) compared to diploids in a mixed tropical urban population.

In mixed-ploidy populations, newly formed polyploids initially occur at low frequencies when compared to diploids. However, polyploidy may lead to morphological and phenological changes, which promote reproductive isolation and favor polyploid establishment and reproductive success. Additionally, previous studies have shown that polyploidy can confer some adaptive advantages to organisms in stressful environments. Here, we investigate variation in reproductive phenology, floral traits and reproductive success between diploid and autotetraploid trees of Libidibia ferrea (Mart. Ex Tul.) L.P. Queiroz (Leguminosae) in a mixed tropical urban population, a stressful environment. We assessed ploidy levels, flowering and fruiting phenology, flowering synchrony, floral and reproductive biology, pollination and fruit and seed set. We tested the hypothesis that autotetraploid individuals have a higher frequency of pollinators and higher fruit and seed set per inflorescence (as a proxy of reproductive success) than diploids in an urban green space. Libidibia ferrea is a good model to test our hypothesis because it is self-incompatible (i.e. relies on pollinators to set fruits). In the urban ecosystem studied, we found that diploids flowered for 6-7 months/year and autotetraploids for 3-5 months/year. Flowering synchrony was low between and within cytotypes and even though autotetraploids and diploids exhibited some overlap in flowering period, diploids flowered alone for 2-3 months. Autotetraploids had significantly more flowers per inflorescences, larger flowers and larger pollen grains (as expected for polyploids), but also a higher frequency of visits by legitimate pollinators including two exclusive ones, and higher fruit and seed set per inflorescence when compared to diploids, despite having a shorter flowering period. Our findings reveal some advantages for polyploids over their related diploids in a tropical urban green space. Also, our results highlight the need for more studies that seek to understand abiotic mechanisms affecting reproductive output of polyploids in urban ecosystems.

Plant-pollinator interactions in urban ecosystems worldwide: A comprehensive review including research funding and policy actions.

Urbanization has rapidly increased in recent decades and the negative effects on biodiversity have been widely reported. Urban green areas can contribute to improving human well-being, maintaining biodiversity, and ecosystem services (e.g. pollination). Here we examine the evolution of studies on plant-pollinator interactions in urban ecosystems worldwide, reviewing also research funding and policy actions. We documented a significant increase in the scientific production on the theme in recent years, especially in the temperate region; tropical urban ecosystems are still neglected. Plant-pollinator interactions are threatened by urbanization in complex ways, depending on the studied group (plant or pollinator [generalist or specialist]) and landscape characteristics. Several research opportunities emerge from our review. Research funding and policy actions to pollination/pollinator in urban ecosystems are still scarce and concentrated in developed countries/temperate regions. To make urban green spaces contribute to the maintenance of biodiversity and the provision of ecosystem services, transdisciplinary approaches (ecological-social-economic-cultural) are needed.

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

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 functional diversity of reproductive traits was affected only by disturbance. Changes in plant community structure promoted by chronic anthropogenic disturbance and aridity will likely threaten plant-animal interactions, thereby compromising the functioning of communities and the persistence of biodiversity in the Caatinga.

Flowering and fruiting synchronization, pollen number, floral visitors and reproductive success of Paubrasilia echinata (brazilwood; Leguminosae) in tropical urban ecosystem in comparison to Atlantic forest remnant: A dataset description.

In this article, we supply raw data on the reproductive biology and frequency of pollinators of Paubrasilia echinata, a threatened tree, endemic to the Brazilian Atlantic forest, which is largely used in Brazilian urban areas (e.g. avenues, parks and squares) due to its ornamental potential. Specifically, we share data on the reproductive phenology, pollen/flower, floral visitors and seed set of P. echinata in urban and natural ecosystems. This dataset article is related to the original research article "Reduced reproductive success of the endangered tree brazilwood (Paubrasilia echinata, Leguminosae) in urban ecosystem compared to Atlantic forest remnant: lessons for tropical urban ecology" (Oliveira et al., 2019). As urbanization is thought to negatively impact the maintenance of plant communities by affecting ecological key interactions, such as pollination, we believe that data as the supplied here are relevant and could support the planning of urban green spaces to maintain viable communities of plants and animals. This is especially valid for tropical urban ecosystems since most of the studies on plant ecology have been developed in temperate regions and there are still several gaps on the knowledge of ecological functions and ecosystems services (e.g. pollination) in urban green areas in the tropics.

Climate change will reduce suitable Caatinga dry forest habitat for endemic plants with disproportionate impacts on specialized reproductive strategies.

Global climate change alters the dynamic of natural ecosystems and directly affects species distributions, persistence and diversity. The impacts of climate change may lead to dramatic changes in biotic interactions, such as pollination and seed dispersal. Life history traits are extremely important to consider the vulnerability of a species to climate change, producing more robust models than those based primarily on species distributions. Here, we hypothesized that rising temperatures and aridity will reduce suitable habitats for the endemic flora of the Caatinga, the most diverse dry tropical forest on Earth. Specifically, species with specialized reproductive traits (e.g. vertebrate pollination, biotic dispersal, obligatory cross-pollination) should be more affected by climate change than those with generalist traits. We performed two ecological niche models (current and future) to simulate the effects of climate change on the distribution area of endemic species in relation to life-history traits. We used the MIROC-ESM and CCSM4 models for both intermediate (RCP4.5) and highest predicted (RCP8.5) GHG emission scenarios, with a resolution of 30' (~1 km2). Habitat with high occurrence probability (>80%) of endemic species will be reduced (up to ~10% for trees, ~13% for non-arboreous, 10-28% for species with any pollination/reproductive system), with the greatest reductions for species with specialized reproductive traits. In addition, the likely concentration of endemic plants in the extreme northeastern portion of the Caatinga, in more mesic areas, coincides with the currently most human-modified areas of the ecosystem, which combined with climate change will further contract suitable habitats of endemic species. In conclusion, plant species endemic to the Caatinga are highly vulnerable to even conservative scenarios of future climate change and may lose much of their climatic envelopes. New protected areas should be located in the northeastern portion of the Caatinga, which hosts a more favorable climate, but is currently exposed to escalating agricultural intensification.

Phenology, nectar dynamics and reproductive success of Inga vera (Leguminosae) in monospecific plantations and forest remnants in Atlantic forest: Dataset exploration.

Distinct approaches have been adopted for tropical forest restoration in the last decades. The long-term viability of these restored forests and their capacity to provide the required services demand continuous evaluation to guide future initiatives. In addition, the resilience and maintenance of plant and animals communities in restored forests in tropical regions are closely related to the recovery of animal-mediated interactions. We provide, in this article, raw data related to the reproductive ecology of Inga vera, one of the most common tree species used in forest restoration initiatives in the Brazilian northeastern Atlantic forest. Specifically, we explore data on phenology, nectar dynamics and reproductive success of I. vera in natural and planted (monospecific) populations. This data article is related to the research article "Pollination partial recovery across monospecific plantations of a native tree (Inga vera, Leguminosae) in the Atlantic forest: lessons for restoration" (Cruz-Neto et al., 2018) [1].

Genetic and ecological outcomes of Inga vera subsp. affinis (Leguminosae) tree plantations in a fragmented tropical landscape.

Planting of native trees for habitat restoration is a widespread practice, but the consequences for the retention and transmission of genetic diversity in planted and natural populations are unclear. Using Inga vera subsp. affinis as a model species, we genotyped five natural and five planted populations in the Atlantic forest of northeastern Brazil at polymorphic microsatellite loci. We studied the breeding system and population structure to test how much genetic diversity is retained in planted relative to natural populations. We then genotyped seedlings from these populations to test whether genetic diversity in planted populations is restored by outcrossing to natural populations of I. vera. The breeding system of natural I. vera populations was confirmed to be highly outcrossing (t = 0.92; FIS = -0.061, P = 0.04), with populations showing weak population substructure (FST = 0.028). Genetic diversity in planted populations was 50% less than that of natural populations (planted: AR = 14.9, HO = 0.865 and natural: AR = 30.8, HO = 0.655). However, seedlings from planted populations showed a 30% higher allelic richness relative to their parents (seedlings AR = 10.5, parents AR = 7.6). Understanding the processes and interactions that shape this system are necessary to provide ecologically sensible goals and successfully restore hyper-fragmented habitats. Future restoration plans for I. vera must consider the genetic diversity of planted populations and the potential for gene flow between natural populations in the landscape, in order to preserve ecological interactions (i.e. pollination), and promote opportunities for outcrossing.