Assessing bias and knowledge gaps on seed ecology research: implications for conservation agenda and policy

Abstract

Sampling biases permeate ecological research and result in knowledge gaps that have vital consequences for conservation planning. The consequences of knowledge gaps on species identity and distribution (the Wallacean and Linnean shortfalls, respectively) have become apparent recently, but we know little about the extent that research biases and knowledge gaps on traits that influence species' niches (the Hutchinsonian shortfall) affect conservation policy. To examine whether knowledge of species' traits based on seed ecology is geographically, phylogenetically, and ecologically biased, we retrieved research data on seed germination, seed dormancy, seed dispersal, seed banks, seed predation, and seed removal from a database of 847 papers, 1648 species, and 5322 cases. Brazil was selected as a model system for megadiverse, undersampled countries. Kernel density maps showed that research was geographically biased towards highly populated sites, with vast areas remaining historically unexplored. We also show that research was clustered into protected areas. We detected a significant positive phylogenetic bias at genus-level, indicating research concentration in few genera and lower relative bias rates for many herbaceous genera. Unexpectedly, information on seed banking was available for only 74 (3.4%) of threatened species, which suggests that information deficits are highest for species with critical needs for ex situ conservation strategies. Tree, fleshy-fruited, and biotic dispersal species were disproportionately overstudied. Our data indicate that information deficits on seed ecology preclude our ability to effectively restore ecosystems and to safeguard endangered species. We call for a systematic improvement of environmental agenda in which policy makers and scientists target sites, clades, and functional groups historically neglected. Lessons from developed countries and collaborative efforts will be important for megadiverse, underdeveloped countries to achieve the targets of international agreements that depend on seed ecology knowledge aiming to secure biological diversity and ecosystem services.

Ex situ cultivation entails high risk of seed dormancy loss on short‐lived wild plant species

“…Our findings are therefore not only important for restoration and reintroduction programmes, but also for the research on germination characteristics and seed longevity. Germination requirements of wild seeds are still mostly unknown and one of the biggest obstacles in effective seed banking of wild species for conservation purposes (Godefroid et al, 2010;Hay & Probert, 2013;Ribeiro, Teixido, Barbosa, & Silveira, 2016). Researchers have just begun to fill this gap of knowledge (Godefroid et al, 2013;Merritt et al, 2014), and protocols that ensure optimal germination and breaking of seed dormancy are available online (e.g.…”

Duality of interaction outcomes in a plant–frugivore multilayer network

“…Third, it is already known that rodents destroy large seeds; we chose to focus our study on the interaction outcome for small seeds. Despite these limitations, our study goes one step further than similar studies on frugivorous vertebrates, as we were able to assess the viability of all apparently intact, small seeds found in the fecal samples, while studies based on germination tests are subject to several other potential flaws related to germination methods and seed dormancy (Heer et al 2010), which in any case are poorly known for most tropical species (Ribeiro et al 2016). Furthermore, most studies that apply tetrazolium tests limit them to a subset of the plant species that might be dispersed by a focal frugivore species (Traveset et al 2016).…”

Ex situ conservation of threatened plants in Brazil: a strategic plan to achieve Target 8 of the Global Strategy for Plant Conservation

“…1, see Harding et al 2013) is needed before plants or seeds can be effectively conserved in ex situ institutions (Costa et al 2017). Unfortunately, these data are still lacking for the vast majority of native species, let alone the threatened ones (Ribeiro et al 2016).…”

“…1). We need to reduce both the phylogenetic and geographic biases that permeate the knowledge on the seed ecology (Ribeiro et al 2016). Reducing the phylogenetic bias means we need to conserve species in families other than Cactaceae, Bromeliaceae and Orchidaceae, which are the dominant in ex situ collections.…”