Ecology as a Tool to Assist Conservation of a Rare and Endemic Mediterranean Plantago Species

Abstract

Reviewing the ecological studies on the endangered endemic Plantago almogravensis Franco, an Al-hyperaccumulator plant, and combining these with morphological, physiological, biochemical, and molecular data, significant knowledge on the limiting factors that cause its narrow geographical distribution and rarity status is achieved, which can contribute to suited conservation guidelines. Emphasis was given on (i) the major factors limiting P. almogravensis’ ecological niche (biotic and abiotic); (ii) phases of the life cycle and population dynamics; and (iii) and the phylogenetically close taxa (Plantago subulata aggregate) in order to fill the knowledge gaps in the uniqueness of P. almogravensis ecology, its phylogeny, and conservation status. The identification of relevant ecological data and using plant functional (morphological and physiological) traits, as well as genetic attributes, substantiate into a powerful tool to guide protection and conservation measures, usable toward this and other endangered hyperaccumulator plant species. Knowledge of the limitations of this strongly narrowly distributed plant allows for better design of conservation measures and to guide value and investment strategies in order to secure the species’ current area (habitat conservation and reclamation), direct the expansion of the existing population (assisting in populational densification and colonization), and/or grant ex situ conservation (genetic resources conservation).

Plant-arthropod interactions of an endangered California lupine

“…Insects were identified to family and received lower classifications if possible (Carvalho, 1955;Herring, 1976;Slater and Baranowski, 1978;Schuh and Slater, 1995;Gibson, Huber and Wooley, 1997;Ross, Thomas and Skelley, 2002;Daniel and Franz, 2012;Hoddle, Mound and Paris, 2012;Marshall, 2012; Iowa State University Department of Entomology, 2017). Specimens identified to family were sorted into putative species based on morphology, or morphospecies (Samways, McGeoch and New, 2010).…”

“…Plant-arthropod interactions, through processes such as pollination, herbivory, and frugivory, play an important role in the reproductive success of plant species (Strong et al 1995, Nemec andBragg, 2008;Schweizer et al 2013). Low pollinator visitation diversity or abundance can explain reduced distribution, low reproductive output, or failure to establish novel plant populations in habitats that are otherwise abiotically suitable (Karron, 1987;Kearns, Inouye and Waser, 1998).…”

“…Herbivorous arthropods meanwhile have been shown to impact establishment and seed production of plants (Bevill, Louda and Stanforth, 1999;Münzbergová and Herben, 2005). Both the mutualistic and antagonistic interactions between plants and arthropods are important drivers in determining the survival of a plant (Stahl, Hilfiker and Reymond, 2018).…”

“…The loss of coastal back dune habitat due to land conversion, fragmentation, and competition with the invasive perennial veldt grass (Ehrharta calycina Sm., Poaceae) limit the range and potential for natural regeneration of theL. nipomensis populations (Skinner and Pavlik, 1994). The entire extant population is geographically isolated within a 5 km 2 area along the central California coast in the Guadalupe-Nipomo Dune Complex and is comprised of seven dispersed colonies.…”

“…A foundational study ofL. nipomensis by Walters and Walters (1989) primarily focused on abiotic drivers of reproduction, specifically changes observed in flowering and fruit set as a factor of rainfall received; this publication also includes a record of herbivorous arthropod interactions, but did not specifically include pollinator observations. Although other annual lupines have had interactions with known pollinators, the absence of pollinator observations has led researchers to hypothesize that L. nipomensis is capable of both self-pollinating as well as outcrossing (USFWS 2019).…”