Why are some plant species missing from restorations? A diagnostic tool for temperate grassland ecosystems

Abstract

The U.N. Decade on Ecosystem Restoration aims to accelerate actions to prevent, halt, and reverse the degradation of ecosystems, and re-establish ecosystem functioning and species diversity. The practice of ecological restoration has made great progress in recent decades, as has recognition of the importance of species diversity to maintaining the long-term stability and functioning of restored ecosystems. Restorations may also focus on specific species to fulfill needed functions, such as supporting dependent wildlife or mitigating extinction risk. Yet even in the most carefully planned and managed restoration, target species may fail to germinate, establish, or persist. To support the successful reintroduction of ecologically and culturally important plant species with an emphasis on temperate grasslands, we developed a tool to diagnose common causes of missing species, focusing on four major categories of filters, or factors: genetic, biotic, abiotic, and planning & land management. Through a review of the scientific literature, we propose a series of diagnostic tests to identify potential causes of failure to restore target species, and treatments that could improve future outcomes. This practical diagnostic tool is meant to strengthen collaboration between restoration practitioners and researchers on diagnosing and treating causes of missing species in order to effectively restore them.

Unveiling the resistance of native weed communities: insights for managing invasive weed species in disturbed environments

“…and Tsuga canadensis facilitate succession by creating microclimates or offering shade for light-sensitive species to thrive. Their adaptability to local conditions renders native weeds resilient to natural disturbances like droughts, floods, and wildfires, enabling them to sustain their role within the succession process (De Vitis et al, 2022). Native populations harbour significant genetic diversity, ensuring their longterm adaptability to changing environmental conditions and allowing them to respond effectively to new challenges (Cristescu, 2016).…”

“…Native weeds are integral to ecological succession, depending on the succession stage and the characteristics of the weed species involved (Banerjee et al ., 2017). For example, Epilobium angustifolium and Chamerion angustifolium rapidly colonise bare ground during ecological succession after wildfires, providing an important food source and habitat for pollinators; their rapid growth helps prevent soil erosion and facilitates woody plant regeneration (De Vitis et al ., 2022). Other examples include Solidago spp.…”

Genetic diversity assessment of Helichrysum arenarium (Asteraceae) for the genetic restoration of declining populations

“…Assessment of genetic diversity of populations of critically endangered species has been recognized as important for the preparation of restoration projects, and genetic restoration as an essential goal in conservation achievements (e.g., Broadhurst et al., 2023; De Vitis et al., 2022; Mijangos et al., 2015; Wei et al., 2023). Indeed, genetic tools allow for identifying a number of key processes involved in population viability, in particular for plant species: mating processes, genetic erosion, inbreeding, pollen and seed dispersal, sexual recruitment, clonal extent, and progeny genetic quality (Aguilar et al., 2019; Doyle et al., 2023; Van Rossum, 2023; Van Rossum et al., 2022).…”

“…Indeed, genetic tools allow for identifying a number of key processes involved in population viability, in particular for plant species: mating processes, genetic erosion, inbreeding, pollen and seed dispersal, sexual recruitment, clonal extent, and progeny genetic quality (Aguilar et al., 2019; Doyle et al., 2023; Van Rossum, 2023; Van Rossum et al., 2022). Depending on the identified failures, additional interventions to ecological restoration may be required to achieve demographically and genetically viable and evolutionary resilient populations (De Vitis et al., 2022; Gargiulo et al., 2021; Ottewell et al., 2016). For instance, increasing genetic diversity and the number of compatible mates is necessary when spatially isolated plant populations are genetically depauperate and inbred, which may be achieved by assisted gene flow actions such as hay transfer, plant translocation, and cross‐pollination (e.g., Barmentlo et al., 2018; Kaulfuß & Reisch, 2021; Ottewell et al., 2016; Ralls et al., 2018).…”

“…Depending on the identified failures, additional interventions to ecological restoration may be required to achieve demographically and genetically viable and evolutionary resilient populations (De Vitis et al, 2022;Gargiulo et al, 2021;Ottewell et al, 2016). For instance, increasing genetic diversity and the number of compatible mates is necessary when spatially isolated plant populations are genetically depauperate and inbred, which may be achieved by assisted gene flow actions such as hay transfer, plant translocation, and cross-pollination (e.g., Barmentlo et al, 2018;Kaulfuß & Reisch, 2021;Ottewell et al, 2016;Ralls et al, 2018).…”