Human-induced biotic invasions and changes in plankton interaction networks

Summary: Pervasive and accelerating changes to ecosystems due to human activities remain major sources of uncertainty in predicting the structure and dynamics of ecological communities. Understanding which biotic interactions within natural multitrophic communities are weakened or augmented by invasions of non-native species in the context of other environmental pressures is needed for effective management. We used multivariate autoregressive models with detailed time-series data from largely freshwater and brackish regions of the upper San Francisco Estuary to assess the topology, direction and strength of trophic interactions following major invasions and establishment of non-native zooplankton in the early 1990s. We simultaneously compared the effects of fish and clam predation, environmental temperature and salinity intrusion using time-series data from >60 monitoring locations spanning more than three decades. We found changes in the networks of biotic interactions in both regions after the major zooplankton invasions. Our results imply an increased pressure on native herbivores; intensified negative interactions between herbivores and omnivores; and stronger bottom-up influence of juvenile copepods but weaker influence of phytoplankton as a resource for higher trophic levels following the invasions. We identified salinity intrusion as a primary pressure but showed relatively stronger importance of biotic interactions for understanding the dynamics of entire communities. Synthesis and applications. Our findings highlight the dynamic nature of biotic interactions and provide evidence of how simultaneous invasions of exotic species may alter interaction networks in diverse natural ecosystems over large spatial and temporal scales. Efforts to restore declining fish stocks may be in vain without fully considering the trophic dynamics that limit the flow of energy to target populations. Focusing on multitrophic interactions that may be threatened by invasions rather than a limited focus on responses of individual species or diversity is likely to yield more effective management strategies. © 2014 British Ecological Society

Researcher self‐care and caring in the research community

This paper seeks to begin a discussion on researcher self‐care in response to the state of contemporary academia, which sees increasing issues of academic stress and anxiety, and the growing use of facile metrics. Specifically, we wish to explore the potential a critical engagement with self‐care poses for ourselves as academics and the communities of which we are a part – what kinpaisby (2008) refers to as the “communiversity.” Our central argument is that self‐care may be regarded as a radical act that can push against the interests of the neoliberal university. We illustrate how researcher self‐care can be engaged as a reflexive process that operates to create and inform change within our communities through recognising ourselves as networked actors, rather than self‐contained individuals as the neoliberal ideology would have us believe. This paper is intended as an opening towards a much larger discussion regarding academia – of the communities, work environments, and “impacts” we wish to be a part of and how to begin working towards realising these

Complex Feeding Tracks of the Sessile Herbivorous Insect Ophiomyia maura as a Function of the Defense against Insect Parasitoids

Because insect herbivores generally suffer from high mortality due to their natural enemies, reducing the risk of being located by natural enemies is of critical importance for them, forcing them to develop a variety of defensive measures. Larvae of leaf-mining insects lead a sedentary life inside a leaf and make conspicuous feeding tracks called mines, exposing themselves to the potential risk of parasitism. We investigated the defense strategy of the linear leafminer Ophiomyia maura Meigen (Diptera: Agromyzidae), by focusing on its mining patterns. We examined whether the leafminer could reduce the risk of being parasitized (1) by making cross structures in the inner area of a leaf to deter parasitoids from tracking the mines due to complex pathways, and (2) by mining along the edge of a leaf to hinder visually searching parasitoids from finding mined leaves due to effective background matching of the mined leaves among intact leaves. We quantified fractal dimension as mine complexity and area of mine in the inner area of the leaf as interior mine density for each sample mine, and analyzed whether these mine traits affected the susceptibility of O. maura to parasitism. Our results have shown that an increase in mine complexity with the development of occupying larvae decreases the probability of being parasitized, while interior mine density has no influence on parasitism. These results suggest that the larval development increases the host defense ability through increasing mine complexity. Thus the feeding pattern of these sessile insects has a defensive function by reducing the risk of parasitism

Illegal wildlife trade and the persistence of “plant blindness”

Societal Impact Statement A wide variety of plant species are threatened by illegal wildlife trade (IWT), and yet plants receive scant attention in IWT policy and research, a matter of pressing global concern. This review examines how “plant blindness” manifests within policy and research on IWT, with serious and detrimental effects for biodiversity conservation. We suggest several key points: (a) perhaps with the exception of the illegal timber market, plants are overlooked in IWT policy and research; (b) there is insufficient attention from funding agencies to the presence and persistence of illegal trade in plants; and (c) these absences are at least in part resultant from plant blindness as codified in governmental laws defining the meaning of “wildlife.” Summary This review investigates the ways in which “plant blindness,” first described by Wandersee and Schussler (1999, p. 82) as “the misguided anthropocentric ranking of plants as inferior to animals,” intersects with the contemporary boom in research and policy on illegal wildlife trade (IWT). We argue that plants have been largely ignored within this emerging conservation arena, with serious and detrimental effects for biodiversity conservation. With the exception of the illegal trade in timber, we show that plants are absent from much emerging scholarship, and receive scant attention by US and UK funding agencies often driving global efforts to address illegal wildlife trade, despite the high levels of threat many plants face. Our article concludes by discussing current challenges posed by plant blindness in IWT policy and research, but also suggests reasons for cautious optimism in addressing this critical issue for plant conservation

Participation in biocultural diversity conservation : insights from five Amazonian examples

Unidad de excelencia María de Maeztu CEX2019-000940-MThe past three decades have seen the emergence of myriads of initiatives focused on conserving, revitalizing, and maintaining Indigenous and Local Knowledge (ILK) as part of biocultural approaches to conservation. However, the extent to which these efforts have been participatory has been often overlooked. In this chapter, we focus on five prominent ILK conservation initiatives in the Amazon Basin to examine the participation of Indigenous Peoples and Local Communities (IPLCs) in ILK conservation. Our review illustrates several examples of ILK conservation initiatives offering substantial opportunities for meaningful IPLC participation over the long term. Overall, our case studies suggest that the development of robust and inclusive decision-making processes is essential to optimize IPLC participation in ILK conservation, thereby increasing the legitimacy of these initiatives. Our review is not an exhaustive account of the breadth and depth of all initiatives promoting participatory biocultural conservation in this region, but it illustrates that there are many strategies that can help foster IPLC engagement and lead the participatory turn in biocultural conservation

The natural exclusion of red deer from large boulder grazing refugia and the consequences for saxicolous bryophyte and lichen ecology

Large boulder grazing refugia permitted comparison of saxicolous bryophyte and lichen assemblages with those boulder tops accessible to red deer (Cervus elaphus) on a sporting estate in northwest Scotland. Plant succession was predicted to occur unchecked by grazing on the tops of these large boulders with cascading effects on bryophytes and lichens—assuming boulders had been in place over the same time period. Fifty pairs of boulders (one ≥2 m and the other accessible to red deer) were selected at random from various locations below north-facing crags. Percentage cover of each bryophyte and lichen species was estimated from three randomly placed quadrats on each boulder top. Due consideration was given to the influence of island biogeography theory in subsequent model simplification. Mean shrub cover and height, leaf-litter, bryophyte cover and bryophyte species richness were significantly higher within quadrats on large boulder tops that naturally excluded red deer. Lichen cover and lichen species richness were significantly higher on boulder tops accessible to red deer. Lichen cover was in a significant negative relationship with bryophyte cover, shrub cover and litter cover. Bryophyte cover showed a significant positive relationship with shrub height but there was an optimum shrub cover. Natural exclusion of red deer from the tops of large boulders has facilitated plant succession. The results suggest that grazing arrests the lithosere on boulder tops accessible to red deer at an early plagioclimax favouring saxicolous lichens. The results are relevant to situations where red deer might be excluded from boulder fields that hold lichen assemblages of conservation value