Land Degradation and Its Impacts on Ecosystem Services in the Nigerian Guinea Savannah: Implications for Sustainable Land Management

Land degradation is a major environmental concern. Globally, land degradation directly impacts about 1.5 to 3.2 billion people by affecting water and nutrient cycles, reducing food and biomass production, and adversely affecting livelihoods that are dependent on land and natural resources. Land degradation, its drivers, and its impacts manifest differently depending on the social and ecological contexts. Thus, attention to the context in analysing land degradation and its proximate and underlying causes will yield insights to foster sustainable land management (SLM). Although land degradation has been implicated in various environmental and development challenges in Africa, knowledge about land degradation in some regions remains inadequate to support the identification of SLM practices. The Guinea savannah zone in Nigeria is one such region, facing widespread and severe land degradation. The region has lost much of its native vegetation due to the combined effects of land degradation, deforestation, and land use changes. Land degradation has been associated with farmer–herder conflicts, communal clashes, out-migration, and food insecurity. These impacts are likely to worsen as climate change progresses and in the absence of SLM. Thus, the overarching aim of this study is to improve understanding of the spatial distribution of land degradation in the Nigerian Guinea Savannah (NGS) and its drivers and thus derive insights into the sustainable management of its land resources. The insights will also help inform pathways to achieving land degradation neutrality (LDN), a global environmental goal. Its objectives are to (1) assess human-induced biomass loss as a proxy for land degradation in the NGS; (2) identify characteristic patterns of social and ecological factors associated with land degradation in the region and analyse their implications for land governance and SLM; (3) examine land users’ perceptions of land degradation and its implications for SLM, using Niger state as a case study; and (4) examine the potentials for operationalizing LDN in Nigeria. These four objectives were addressed in four studies. The research questions were investigated with a mixed-methods approach combining satellite remote sensing data and analysis and geographic information systems (GIS) with field surveys, focus group discussions, key informant interviews, and a review of environmental policies in Nigeria. Results from assessing human-induced biomass loss, as a proxy for land degradation (Study 1) showed a declining trend in annual mean normalized difference vegetation index (NDVI) and annual NDVI anomalies observed in the NGS between 2003 and 2018. The indices were from the Moderate Resolution Imaging Spectroradiometer (MODIS). Overall, the study revealed that 38% (251K km2) of the NGS experienced degradation, 14% (91K km2) experienced improvement, and the remaining 48% (320K km2) was stable. Land degradation is mostly evident in states bordering the northwest to the central and northeast of the NGS, such as Niger state. These results show that land degradation affects a substantial part of the study area. Thus, identifying characteristic patterns of social and ecological factors associated with land degradation in the region and analysing their implications for land governance and SLM (Study 2) provided further insights. The archetype analysis identified nine archetypes dominated by (1) protected areas; (2) very high-density population; (3) moderately high information and knowledge access; (4) low literacy levels and moderately high poverty levels; (5) rural remoteness; (6) remoteness from a major road; (7) very high livestock density; (8) moderate poverty level and nearly level terrain; and (9) very rugged terrain remote from a major road. Among these archetypes, four archetypes characterized by very high-density population, moderately high information and knowledge access, and moderately high poverty level, as well as remoteness from a major town, were associated with 61.3% large-area degradation. The other five archetypes, covering 38.7% of the area, were associated with small-area degradation. Although the MODIS satellite analysis (Study 1) and the archetype analysis of spatial data on land degradation drivers, hint at the different types of land use and management including the ecological aspects of land degradation (Study 2), Study 3 examines the perspectives of land users on land degradation. A questionnaire survey was used to capture local land users’ perceptions of land degradation. The assessment of local land users’ perceptions of land degradation in predominantly rural remote farming communities was necessary to provide insights to further guide land governance and management. Thus, focused on the rural remote archetypes and its analysed communities far from major towns but with a moderately low prevalence of land degradation drivers such as population density, protected areas, and flat terrain. Using a case study on Niger state, an administrative unit in the NGS and a Principal Component Analysis, Study 3 identified key components in land users’ perceptions of land degradation characteristics and drivers and SLM. They include (1) four perception dimensions of land degradation characteristics: (2) two perception dimensions of land degradation drivers, and (3) six perception dimensions of sustainable land management. The four major dimensions of perceptions of land degradation in the study context include vegetation-condition-dominated characteristics, soil-condition-dominated characteristics, and vegetation with Sudano-Sahelian characteristics as well as land use land cover (LULC) with the prevalence of drier conditions. The two categories of land degradation drivers are human-activity-dominated drivers at a smaller scale and nature-dominated drivers at a larger scale. The two categories of land degradation drivers are human activities dominated drivers at a smaller scale and larger-scale drivers (nature-driven). The dimensions of SLM identified include institutional actors’ effect; natural resources management and environmentally friendly agricultural practices as well as tree-based initiatives; conservation initiatives and policy initiatives. The study showed that land degradation in Niger State is due to land use pressure from within the state and from migrant resource users with limited cultural attachments to local land management approaches. A spatial differentiation in dependence on natural resources showed that of the three geopolitical zones in Niger State, the zone with more diversified livelihood alternatives from agriculture, B, has less degradation than the other two zones, A and C. The archetypes approach (Study 2) identified policies and practices addressing increasing population in combination with other socio-economic factors such as poverty reduction as important. Other strategies include creating awareness about land degradation, the promotion of sustainable practices, and various forms of land restoration, such as tree planting, as ways of progressing towards LDN. In addition, Study 3 on key dimensions based on land users’ perceptions identified environmentally friendly agriculture initiatives such as farmer-managed natural regeneration and a bottom-up approach involving traditional village heads to tackle land degradation. Ranking of SLM using the relative importance index (RII) (Study 3) showed that land users perceive institutional actors (70.0%), technological practices (67.6%), conservation practices (66.8%), and policy initiatives (66.5%) as effective SLM. Connecting the insights from the three previous studies on land degradation in the NGS, Study 4 examined ways to operationalize LDN in Nigeria. Study 4 reviewed literature, assessed spatial datasets, and analysed national policies to examine the need to contextualize LDN according to the main agro-ecological zones in Nigeria, which include the NGS. The study also identified two promising entry points for operationalizing LDN; these are incentivizing and promoting SLM practices among local resource users and mainstreaming SLM initiatives in sectors such as agriculture and the environment. To support SLM measures, reform of national land use policy is needed to address the current limitations of land tenure in Nigeria. In conclusion, this study has identified large areas of the NGS affected by land degradation and identified the typologies of degradation extent, thus making it easier to target SLM measures. Because land degradation depends on land users’ perceptions and contexts, knowledge gained can inform approaches to motivate the land users themselves to address land degradation. Insights gained from the focus on the NGS have informed contributions to examine how changes in land use affect biodiversity and ecosystem services in the Río de la Plata grasslands (RPG), one of the most modified savannah biomes in the world, managed by Argentina, Brazil, and Uruguay. Results showed that a strict regulation of LULC change in the RGP is required to address land degradation. Studies in both contexts thus show the importance of appropriate policies to support SLM. These studies also highlight further research questions, such as what the key socio and economic determinants shaping land users’ perceptions of land degradation are and how land users prioritize ecosystem services, as additional pathways to align SLM practices to the social and ecological context

Genetic analysis of latrophilin in the toxicity of combined latrotoxins for C. elegans

Black widow spider venom (BWSV) contains high molecular weight proteins called latrotoxins (LTX) that induce catastrophic neurotransmitter release from nerve terminals, and one toxin, α-latrotoxin, is known to bind with high affinity to three neural proteins in mammals, including latrophilin (lat-1) a member of the class B family of G-protein coupled receptors. We have established C.elegans as a model organism to study the function of the binding protein, lat-1 and its role in regulating neurotransmitter release by latrotoxins. However, a lat-1-knockout worm is required for determining the function of the lat-1 gene. The lat-1(ok1465) allele has a deletion of the lat-1 gene, and ~95-98% of lat-1(ok1465) homozygous worms arrest or die before adulthood, with only ~2-5 adult offspring per animal. Micro-injection of the B0457 cosmid, that contains the full sequence of the lat-1 gene, or the lat-1a cDNA rescued the lethality of the lat-1 worms, thereby showing that lat-1 gene is responsible for the developmental lethality in these worms. Expression of the marker, GFP, under the control of the lat-1 promoter showed that there was expression of GFP during epithelial morphogenesis, and strong expression in the gut from the three-fold stage through to larval stages. The concordance between the site of expression of lat-1::gfp, with the sites of embryonic defects (epithelial enclosure defects; defective attachement of gut) in lat-1(ok1465) animals, provides further evidence that lat-1 is essential for embryonic and larval development. Deletion mutants of lat-1a were constructed to examine the role of domains of this protein. Deletion of sequences after the 4xCys domain of lat-1a did not affect the ability to rescue lethality in the lat-1 worm, while deletion of the C-terminus to the seven transmembrane domain impaired the ability of lat-1a to rescue lat-1 worms, and further deletion of six of seven transmembrane domains (the TM1 construct) yielded a construct that was unable to rescue lat-1 worms. These data suggest an important role for intracellular sequences and seven transmembrane in lat-1a signalling. It was proposed that TM1 could decoy ligand, without causing intracellular signalling. In agreement, the TM1 construct caused a mild phenocopy of the lat-1(ok1465) mutant in wild-type worms, whereas full-length, or non-ligand binding variants of lat-1a caused no such effect. To investigate the putative ligand-binding domain of lat-1a, deletion of residues 62-147 (ΔGBL), 62-250 (ΔHRM) and 62-487 (ΔN) was investigated; while the ΔN construct was incapable of rescuing lat-1(ok1465) worms, deletion of ΔGBL had a minor effect on the ability of lat-1 to rescue the null worms, while ΔHRM had a more marked effect. These data are consistent with a model whereby residues 147-487 are required for ligand binding, and the seventransmembrane and intracellular domains transmit a signal to the inside of the cell. Combined latrotoxins was highly toxic to wild-type C.elegans (LD50 ~4ng/ml), whereas the lat-1 worms were highly (>105-fold) resistant to combined latrotoxins. Lat-1 worms that were transgenic for B0457cosmid, or lat-1a cDNA, were as sensitive to combined latrotoxins as wildtype worm. Truncation of the C-terminus of lat-1a to TM1 yielded worms that had 105-fold resistance to combined latrotoxins, compared to wild-type; thus the intracellular domain of lat-1 is required for mediating combined latrotoxins toxicity. The deletion of galatactose-binding lectin (ΔGBL) in N-terminus lat-1a was sensitive as wild-type, but deletion of hormone receptor motif (ΔHRM) in N-terminus lat-1a showed a reduced sensitivity to combined latrotoxins by ~105-fold. These data showed presence of lat-1 gene was responsible for the rescue of lat-1 worms or toxicity of combined latrotoxins in lat-1 worms, and the absence of lat-1 gene was responsible for the lethality of lat-1 worms and resistance to combined latrotoxins in lat-1 worms

Genetic analysis of latrophilin in the toxicity of combined latrotoxins for C. elegans

Black widow spider venom (BWSV) contains high molecular weight proteins called latrotoxins (LTX) that induce catastrophic neurotransmitter release from nerve terminals, and one toxin, α-latrotoxin, is known to bind with high affinity to three neural proteins in mammals, including latrophilin (lat-1) a member of the class B family of G-protein coupled receptors. We have established C.elegans as a model organism to study the function of the binding protein, lat-1 and its role in regulating neurotransmitter release by latrotoxins. However, a lat-1-knockout worm is required for determining the function of the lat-1 gene. The lat-1(ok1465) allele has a deletion of the lat-1 gene, and ~95-98% of lat-1(ok1465) homozygous worms arrest or die before adulthood, with only ~2-5 adult offspring per animal. Micro-injection of the B0457 cosmid, that contains the full sequence of the lat-1 gene, or the lat-1a cDNA rescued the lethality of the lat-1 worms, thereby showing that lat-1 gene is responsible for the developmental lethality in these worms. Expression of the marker, GFP, under the control of the lat-1 promoter showed that there was expression of GFP during epithelial morphogenesis, and strong expression in the gut from the three-fold stage through to larval stages. The concordance between the site of expression of lat-1::gfp, with the sites of embryonic defects (epithelial enclosure defects; defective attachement of gut) in lat-1(ok1465) animals, provides further evidence that lat-1 is essential for embryonic and larval development. Deletion mutants of lat-1a were constructed to examine the role of domains of this protein. Deletion of sequences after the 4xCys domain of lat-1a did not affect the ability to rescue lethality in the lat-1 worm, while deletion of the C-terminus to the seven transmembrane domain impaired the ability of lat-1a to rescue lat-1 worms, and further deletion of six of seven transmembrane domains (the TM1 construct) yielded a construct that was unable to rescue lat-1 worms. These data suggest an important role for intracellular sequences and seven transmembrane in lat-1a signalling. It was proposed that TM1 could decoy ligand, without causing intracellular signalling. In agreement, the TM1 construct caused a mild phenocopy of the lat-1(ok1465) mutant in wild-type worms, whereas full-length, or non-ligand binding variants of lat-1a caused no such effect. To investigate the putative ligand-binding domain of lat-1a, deletion of residues 62-147 (ΔGBL), 62-250 (ΔHRM) and 62-487 (ΔN) was investigated; while the ΔN construct was incapable of rescuing lat-1(ok1465) worms, deletion of ΔGBL had a minor effect on the ability of lat-1 to rescue the null worms, while ΔHRM had a more marked effect. These data are consistent with a model whereby residues 147-487 are required for ligand binding, and the seventransmembrane and intracellular domains transmit a signal to the inside of the cell. Combined latrotoxins was highly toxic to wild-type C.elegans (LD50 ~4ng/ml), whereas the lat-1 worms were highly (>105-fold) resistant to combined latrotoxins. Lat-1 worms that were transgenic for B0457cosmid, or lat-1a cDNA, were as sensitive to combined latrotoxins as wildtype worm. Truncation of the C-terminus of lat-1a to TM1 yielded worms that had 105-fold resistance to combined latrotoxins, compared to wild-type; thus the intracellular domain of lat-1 is required for mediating combined latrotoxins toxicity. The deletion of galatactose-binding lectin (ΔGBL) in N-terminus lat-1a was sensitive as wild-type, but deletion of hormone receptor motif (ΔHRM) in N-terminus lat-1a showed a reduced sensitivity to combined latrotoxins by ~105-fold. These data showed presence of lat-1 gene was responsible for the rescue of lat-1 worms or toxicity of combined latrotoxins in lat-1 worms, and the absence of lat-1 gene was responsible for the lethality of lat-1 worms and resistance to combined latrotoxins in lat-1 worms

Stakeholder visions for biodiversity conservation in developing countries

The 2014 Conference of the Parties (COP 12) for the Convention on Biological Diversity (CBD) was another step on the road to achieving the Aichi Targets the CBD agreed in 2010. It was also a key step on the way to making progress towards the vision of a more balanced relationship between people and the rest of biodiversity by 2050. Many key issues were left for this COP by negotiators from COP 11 and earlier meetings; such as settling financial issues, articulating clearly the Aichi Targets for national implementation by 2020, or providing clear guidance on capacity-building for developing states. This paper utilizes 22 stakeholder interviews taken at the 2012 Hyderabad COP to develop discussion of ongoing issues in the CBD negotiations. These interviews yielded a number of tractable policy opportunities available for the 2014 Conference to create significant space for developing countries to contribute effectively to global achievement of the Aichi Targets. Breakthroughs and developments at the COP, despite the inevitability of some difficult discussions, will be provided by developing country perspectives. Despite that potential traction, Ministers at the high-level segment noted that progress towards the Aichi targets is insufficient and recognizing there was still much to do on resource mobilization, reaffirmed their commitment to mobilize financial resources from all sources for the effective implementation of the Strategic Plan for Biodiversity 2011–2020. As we enter the second half of the 2011–2020 decade, developing countries must be placed at the center of efforts to improve sustainable use, conservation and benefit sharing of biodiversity around the world

Key dimensions of land users’ perceptions of land degradation and sustainable land management in Niger State, Nigeria

Declining land productivity remains a challenge for agriculture-based livelihoods and for achieving food security. Yet identifying how land users perceive land degradation and their capacity to manage land in an environmentally sustainable manner can influence the measures initiated to address it. Using the case of Niger State, Nigeria, this study examines land users’ perceptions of land degradation and land management measures to address it in the Nigerian Guinea Savannah. We used the Moderate-resolution Imaging Spectroradiometer derived Normalized Difference Vegetation Index as a proxy for degradation status, selecting 30 communities based on the extent of degraded areas. We adapted the World Overview of Conservation Approaches and Technologies, Sustainable Land Management questionnaires to capture perceptions and administered 225 questionnaires to land users. Through key informant interviews, we collected narrative insights and data on perspectives and motivations of land users to understand land degradation situations and to interpret the questionnaire surveys. We analysed data through descriptive statistics, Principal Component Analysis and qualitative analysis. Our analysis identified four perceptions dimensions of land degradation characteristics, two perceptions dimensions of land degradation drivers, and six perceptions dimensions of sustainable land management. The results also confirmed that degradation in Niger State is both due to widespread unsustainable human activities within Niger state and those by migrant farmers and pastoralism from adjoining Sudan Sahelian states that push people further south, a leakage of ongoing land degradation and conflicts in other areas. To deal with local land degradation in Niger State, improved land tenure, alternative livelihood strategies, poverty eradication and awareness, nature-based sustainable land management practices such as tree-based initiatives, environmentally friendly agriculture such as Farmer Managed Natural Regeneration supported by the necessary political will and institutions are critical

Potential benefits of genetic modification (GM) technology for food security and health improvement in West Africa: Assessing the perception of farmers in Ghana and Nigeria

We assessed the perception of farmers towards potential adoption of genetic modification (GM) technology for improving health, food security and agricultural productivity using a semi-structured interview. A total sample of 54 small-scale farmers participated in 6 focus group meetings (FGMs) and 23 in-depth interviews at six locations in Ghana and Nigeria (West Africa). Our results reveal that most farmers have a very poor understanding of GM technology which they often misunderstood as traditional plant breeding biotechnology. While most respondents focused on the potential benefits of GM technology including high-yielding varieties, better nutritional value and shorter growing cycle crop traits, only a few respondents were concerned about the potential health and environmental risks of GM technology. Root and tuber crops such as cassava, yam and sweet potato were mostly discussed for health improvement and food security through GM technology. This study emphasizes the need to recognize challenges such as lack of awareness, inadequate training, low level of education and poor extension services among others in introducing new technology including GM technology to resource poor farmers in African countries like Ghana and Nigeria. We conclude that failure to address these challenges will impede the adoption of GM technology. Therefore, Ghanaian and Nigerian government(s) must put in place policy measures to address these problems.Keywords: Food security, health improvement, genetic modification (GM) technology, Ghana, Nigeria, West Africa farmersAfrican Journal of Biotechnology, Vol. 13(2), pp. 245-256, 8 January, 201

Increasing signs of forest fragmentation in the Cross River National Park in Nigeria: Underlying drivers and need for sustainable responses

Protected areas are expectedly intact habitats for biodiversity and key for ecosystem conservation. However, where inadequately protected, human-induced forest fragmentation can degrade them and reduce their functioning. Therefore, monitoring forests in protected areas is essential to ascertain their protection. This paper assesses forest fragmentation in the Cross River National Park, a biodiversity hotspot in the tropical rainforest of Nigeria. Forest fragmentation was analyzed using the Driver-Pressure-State-Impact-Response framework. Fragmentation analysis of the State used class-level pattern metrics on Landsat and Sentinel images from the years 2000, 2015 and 2020. Forest fragmentation has reduced total forest area, decreased average size of forest patches, increased the number of forest patches and amount of edge. Only the isolation of forest patches has not yet reached a measurable intensity. However, spatio-temporal forest fragmentation over the years 2000, 2015 and 2020 indicates a rising trend, especially between 2015 and 2020. The Drivers, Pressures, Impacts and Responses were investigated through a systematic literature review. Many studies show that the main proximate Drivers of forest fragmentation are agricultural activities mainly by the local communities, demand for forest resources by the growing population, and by external actors through illegal logging and infrastructure building, which have increased. However, wider literature highlight issues of disproportionately blaming local resource users, and the need to examine the neglect of justice, rights and local values, and their implications for sustainable protected areas. Reported Impacts include hindered migration of the endangered Cross River gorilla and impaired ecosystem services like water cycling, carbon sequestration and disease regulation. Responses have generally excluded the local communities, have failed or are yet to become effective. There is thus a need to identify, together with the involved actors, why measures have failed and to implement more sustainable options to reduce fragmentation in the park while addressing local users’ needs

Identification and Functional Clustering of Genes Regulating Muscle Protein Degradation from amongst the Known C. elegans Muscle Mutants

Loss of muscle mass via protein degradation is an important clinical problem but we know little of how muscle protein degradation is regulated genetically. To gain insight our labs developed C. elegans into a model for understanding the regulation of muscle protein degradation. Past studies uncovered novel functional roles for genes affecting muscle and/or involved in signalling in other cells or tissues. Here we examine most of the genes previously identified as the sites of mutations affecting muscle for novel roles in regulating degradation. We evaluate genomic (RNAi knockdown) approaches and combine them with our established genetic (mutant) and pharmacologic (drugs) approaches to examine these 159 genes. We find that RNAi usually recapitulates both organismal and sub-cellular mutant phenotypes but RNAi, unlike mutants, can frequently be used acutely to study gene function solely in differentiated muscle. In the majority of cases where RNAi does not produce organismal level phenotypes, sub-cellular defects can be detected; disrupted proteostasis is most commonly observed. We identify 48 genes in which mutation or RNAi knockdown causes excessive protein degradation; myofibrillar and/or mitochondrial morphologies are also disrupted in 19 of these 48 cases. These 48 genes appear to act via at least three sub-networks to control bulk degradation of protein in muscle cytosol. Attachment to the extracellular matrix regulates degradation via unidentified proteases and affects myofibrillar and mitochondrial morphology. Growth factor imbalance and calcium overload promote lysosome based degradation whereas calcium deficit promotes proteasome based degradation, in both cases myofibrillar and mitochondrial morphologies are largely unaffected. Our results provide a framework for effectively using RNAi to identify and functionally cluster novel regulators of degradation. This clustering allows prioritization of candidate genes/pathways for future mechanistic studies