Progress and prospects for the biological control of invasive alien grasses Poaceae) in South Africa

Historically, invasive alien grasses have not been considered a major threat in South Africa, and as a result, very few resources are allocated to their management. However, there is an increasing awareness of the severe environmental and socio-economic impacts of invasive grasses and the need for appropriate management options for their control. South Africa has a long history of successfully implementing weed biological control (biocontrol) to manage invasive alien plants, however much like the rest of the world, invasive grasses do not feature prominently as targets for biocontrol. The implementation and early indicators of success of the few grass biocontrol programmes globally and the finding that grasses can be suitable targets, suggests that biocontrol could start to play an important role in managing invasive alien grasses in South Africa. In this paper, we evaluated the prospects for implementing novel grass biocontrol projects over the next ten years against 48 grasses that have been determined to represent the highest risk based on their current environmental and economic impacts. The grasses were ranked in order of priority using the Biological Control Target Selection system. Five grasses were prioritised – Arundo donax L., Cortaderia jubata (Lem.) Stapf, Cortaderia selloana (Schult and Schult) Asch. and Graebn., Nassella trichotoma (Hack. ex Arech.), and Glyceria maxima (Hartm.) Holmb., based on attributes that make them suitable biocontrol targets. Arundo donax has already been the target of a biocontrol programme in South Africa. We reviewed the progress made towards the biocontrol of this species and discuss how this programme could be developed going forward. Moreover, we outline how biocontrol could be implemented to manage the remaining four high-priority targets. While biocontrol of grasses is not without its challenges (e.g. unresolved taxonomies, conflicts of interest and a lack of supporting legislation), South Africa has an opportunity to learn from existing global research and begin to invest in biocontrol of high-priority species that are in most need of control

Problematising Local Indigenous Community Research

This book deliberates on developments related to Knowledge Pathing: Multi-, Inter- and Trans-Disciplining in Social Sciences. The book explores the value of this vexed concept in advancing the course for multi-, inter- and trans-disciplinary perspectives, methodologies, theories and epistemologies of knowledge pathing. The discourse on knowledge pathing remains critical in advancing debates and dialogues in the humanities and social sciences spaces of research and studies. This book makes a significant contribution to the scholarly understanding of indigenous knowledge research by focusing on problematising local indigenous community research from Afro-sensed perspectives. The field of indigenous knowledge research and higher education in Africa is complex. Yet, across the continent, higher education has been the sector to least embrace Indigenous Knowledge Systems (IKS) or regard indigenous science as a legitimate source of inspiration for the development of youth and local communities. Higher education institutions and local indigenous communities should thus generate knowledge and power through research. On the other hand, higher education researchers should use their research processes and skills for cross-beneficiation when engaging local indigenous communities. This book embodies the current discourse on decolonisation and the use of indigenous knowledge in research and is intended for research specialists in the field of indigenous knowledge systems

Problematising Local Indigenous Community Research

This book deliberates on developments related to Knowledge Pathing: Multi-, Inter- and Trans-Disciplining in Social Sciences. The book explores the value of this vexed concept in advancing the course for multi-, inter- and trans-disciplinary perspectives, methodologies, theories and epistemologies of knowledge pathing. The discourse on knowledge pathing remains critical in advancing debates and dialogues in the humanities and social sciences spaces of research and studies. This book makes a significant contribution to the scholarly understanding of indigenous knowledge research by focusing on problematising local indigenous community research from Afro-sensed perspectives. The field of indigenous knowledge research and higher education in Africa is complex. Yet, across the continent, higher education has been the sector to least embrace Indigenous Knowledge Systems (IKS) or regard indigenous science as a legitimate source of inspiration for the development of youth and local communities. Higher education institutions and local indigenous communities should thus generate knowledge and power through research. On the other hand, higher education researchers should use their research processes and skills for cross-beneficiation when engaging local indigenous communities. This book embodies the current discourse on decolonisation and the use of indigenous knowledge in research and is intended for research specialists in the field of indigenous knowledge systems

Key changes in gene expression identified for different stages of C4 evolution in Alloteropsis semialata.

C4 photosynthesis is a complex trait that boosts productivity in tropical conditions. Compared to C3 species, the C4 state seems to require numerous novelties, but species comparisons can be confounded by long divergence times. Here, we exploit the photosynthetic diversity that exists within a single species, the grass Alloteropsis semialata, to detect changes in gene expression associated with different photosynthetic phenotypes. Phylogenetically-informed comparative transcriptomics show that intermediates with a weak C4 cycle are separated from the C3 phenotype by increases in the expression of 58 genes (0.22% of genes expressed in the leaves), including those encoding just three core C4 enzymes: ASP-AT, PCK, and PEPC. The subsequent transition to full C4 physiology was accompanied by increases in another 15 genes (0.06%), including only the core C4 enzyme PPDK. These changes likely created a rudimentary C4 physiology, and isolated populations subsequently improved this emerging C4 physiology, resulting in a patchwork of expression for some C4-accessory genes. Our work shows how C4 assembly in A. semialata happened in incremental steps, each requiring few alterations over the previous one. These create short bridges across adaptive landscapes that likely facilitated the recurrent origins of C4 photosynthesis through a gradual process of evolution

The invasive grass genus Nassella in South Africa: a synthesis

Three species of Nassella have naturalized in South Africa. Nassella trichotoma and N. tenuissima are declared weeds under category 1b of the National Environmental Management: Biodiversity Act (NEM:BA) and occur mainly in the montane grasslands of the Western and Eastern Cape provinces. Nassella neesiana is not listed in NEM:BA but is naturalized in the Eastern Cape, Western Cape and Free State provinces. Research conducted in the 1970s and 1980s led to vigorous government-funded awareness and control campaigns which ended in 2000. No research on Nassella distribution or control has been undertaken since then. Despite this hiatus, Nassella remains a dangerous genus in southern Africa, given the serious impacts of these species in similar social-ecological systems in Australia and New Zealand. This paper presents a synthesis of available information about Nassella invasions in South Africa and identifies research gaps. It specifically addresses these questions: What identification issues exist? What is the current spatial distribution of Nassella? What is the autecology of the genus? What are the social-ecological impacts of Nassella? What control measures are currently applied and what are their strengths and limitations? What do we know about Nassella distribution and its response to climate change? This paper highlights many knowledge gaps about Nassella, such as the species’ current distribution range, field identification and detection difficulties, and the uncoordinated control efforts that require urgent research to inform an effective management response