Mangrove system dynamics in Southeast Asia: linking livelihoods and ecosystem services in Vietnam

Across Southeast Asia, human activity has caused rapid mangrove system degradation and loss. In Vietnam, a country undergoing economic transition, mangrove systems are vital to the livelihoods of coastal rural communities. This paper studies three mangrove system-dependent communities on Vietnam’s northern coast. Guided by the sustainable livelihood framework, the paper adopts a mixed methods approach. It presents current uses of mangrove system goods and the factors shaping past livelihood responses to mangrove system change, using livelihood trajectory analysis. Findings demonstrate that communities depend on mangrove systems to different degrees for income, subsistence and to respond to change. However, the rapid development of aquaculture is associated with a significantly reduced and degraded mangrove system commons necessary to support the livelihoods of low-income households. Three distinct livelihood trajectories are identified: consolidator groups able to use their access to a wide range of resources, locked into resilient trajectories; accumulator groups able to use their access to limited resources to move from vulnerable to more resilient trajectories; and marginalised groups facing increasingly reduced access to resources locked into vulnerable trajectories. Vietnam faces challenges in reconciling a more market-orientated economy with the maintenance of mangrove system functions and processes that shape the vulnerability and resilience of livelihood trajectories. Policies and projects promoting the sustainable management of mangrove systems should acknowledge the substantial contribution and multiple uses of mangrove systems in livelihoods, particularly of the poor, and the impact of aquaculture on income equality and livelihood diversity that shapes household resilience and vulnerability

Reflections and recommendations on transitioning from pre- to post-disaster research

Fieldwork often takes place in dynamic, uncertain environments. This is especially true of fieldwork in developing countries. Occasionally events can occur that have significant repercussions for ongoing research involving human participants. For example, political and social unrest, terror attacks, economic crises, epidemics, and natural disasters all have the potential to derail fieldwork plans and to radically alter the circumstances in which researchers operate. However, literature on how to anticipate and navigate these repercussions is limited. While a number of papers have reflected on the difficulties of conducting post‐crisis fieldwork, few have discussed the rather different challenge of dealing with, and adapting to, events that occur during ongoing work. In this paper, we discuss how the 2015 Nepal earthquake – which occurred while we were conducting fieldwork in one of the affected areas – forced us to reassess our research agenda, profoundly affected our relationship with the community we had been working in, and evoked challenging ethical questions in respect to our obligations to our research participants. Based on our reflections, we suggest eight issues that researchers who are engaged in fieldwork in high‐risk or post disaster locations should give consideration to. The issues include matters relating to research design, fieldwork risk and ethics assessment, interaction with research participants, and researcher support

The spatial and temporal characteristics of urban heat island intensity: implications for East Africa’s urban development.

8. Li X, Stringer LC, Dallimer M. 2021.Climate 9 (4) (special issue on The Built Environment in a Changing Climate: Interactions Challenges and Perspectives); 51. https://doi.org/10.3390/cli904005

Does Economic Agglomeration Lead to Efficient Rural to Urban Land Conversion? An Examination of China’s Metropolitan Area Development Strategy

Urbanization involves expansion of the amount of land covered by urban uses. Rural to urban land conversion (RULC) can satisfy demand for the additional space that growing cities require. However, there can be negative consequences, such as the loss of productive agricultural land and/or the destruction of natural habitats. Considerable interest therefore exists among policy makers and researchers regarding how the efficiency of RULC can be maximized. We used the Gini index and a data envelopment analysis to quantify the relationship between RULC and economic development for 17 metropolitan areas in China. We did this from two perspectives: (i) coordination; and (ii) efficiency. We found that economic agglomeration fosters the coordination of the amount of rural land that is allocated to be converted to urban uses. Similarly, economic agglomeration increases the efficiency of RULC in terms of the processes of socio-economic production. Through production technology innovation and readjustment in the scale of input factors, the productive efficiency of RULC can be promoted. Our findings suggest a need to strictly limit the amount of RULC, design differential land management policies according to location and development level, and adjust RULC allocation between different cities. Further, in harnessing the potential of intensive urban land use and restructuring, production factors, including land, can be enhanced through technological innovation. Research presented in this paper provides insights for areas of the world which are yet to undergo the rapid urbanization that China has experienced, but where it is projected to occur over the coming decades

Wild and domestic savanna herbivores increase smaller vertebrate diversity, but less than additively

Cattle and other livestock graze more than a quarter of the world's terrestrial area and are widely regarded to be drivers of global biodiversity declines. Studies often compare the effects of livestock presence/absence but, to our knowledge, no studies have tested for interactive effects between large wild herbivores and livestock at varying stocking rates on small-bodied wild vertebrates. We investigated the effects of cattle stocking rates (none/moderate/high) on the diversity of wildlife 0.05–1,000 kg using camera traps at a long-term exclosure experiment within a semi-arid savanna ecosystem in central Kenya. In addition, by selectively excluding wild ‘mesoherbivores’ (50–1,000 kg) and ‘megaherbivores’ (>1,000 kg; elephant and giraffe), we tested whether the presence of these two wild herbivore guilds (collectively, ‘larger wild herbivores’) mediates the effect of cattle stocking rate on habitat use and diversity of ‘smaller wildlife’ (mammals ranging between 10 and 70 cm shoulder height and birds). Our results show that cattle enhance alpha diversity of smaller wildlife (with or without larger wild herbivore presence) and of all wildlife 0.05–1,000 kg (with or without megaherbivore presence), by altering vegetation structure. However, for smaller wildlife, this effect is less pronounced in the presence of larger wild herbivores, which also shorten grass. In the absence of cattle, mesoherbivore-accessible sites showed higher alpha diversity of smaller wildlife than sites excluding mesoherbivores. Smaller wildlife habitat use was increased by high cattle stocking rates and wild mesoherbivores more in the presence of the other. Synthesis and applications. Our findings imply that grazing, whether by livestock or wildlife, can enhance local savanna wildlife diversity. The biodiversity benefits of localised increases in herbivory are likely to be due to shortened grass and associated visibility improvements (for predator avoidance/foraging). This suggests that land managers can increase local biodiversity by shortening grass, with wild or domestic herbivores (or both), at least in patches within a taller grass matrix

Comparison of several secondary metabolite and elemental ion contents of leaves from Kandelia obovata and Sonneratia caseolaris forests located in the Red River Delta

The two mangrove species Kandelia obovata and Sonneratia caseolaris were widely planted in the Red River delta. Both K. obovata and S. caseolaris forests play an important role in the economic development and environmental protection of the delta. However, chemical responses of the common mangrove forests to different ecological conditions in the delta have not yet been described. In this study, we evaluated chemical responses of K. obovata and S. caseolaris through comparisons of the content of metabolites and element ions in leaves of mangrove plants located under different ecological conditions in the Red River delta. In the low salinity area (Thuy Truong), specific leaf areas of K. obovata and S. caseolaris were much lower while the succulent index was higher compared to those in the high salinity area (Kim Trung). In Kim Trung, both species had a lower ratio of chlorophyll a/chlorophyll b. K. obvata in lower light (under the S. caseolaris canopy) had lower levels of chlorophyll b, resulting in a higher Chla/chlb ratio. There was no difference in the Mg content of leaves between two areas. An increase in Na content in leaves of mangrove plants in the higher salinity area was evident. The high K/Na ratio in leaves were eveluated for both species in high salinity areas. Our results also showed better uptake of K in leaves of S. caseolaris growing in the low salinity conditions (Thuy Truong), i.e. Thuy Truong has more favourable ecological conditions for S. caseolaris. Carotenoid contents in leaves of both species growing in the higher salinity were lower.

Spatial patterns in the adaptive capacity of dryland agricultural households in South Punjab, Pakistan

Climate change and desertification continue to threaten livelihoods in drylands across the globe. This study explores the relative importance of Sustainable Livelihoods Framework components in explaining variation in the adaptive capacity of agricultural households in three districts in the drylands of south Punjab, Pakistan, and to identify spatial patterns in adaptive capacity distribution. Questionnaire generated data were analyzed using Non-Linear Principal Component Analysis and spatial cluster mapping using the Global Moran's I and Anselin Local Moran's I. Natural assets were found to describe most variation among households, followed by physical, financial, human and social assets. Most households with high adaptive capacity were spatially clustered in Rahim Yar Khan, a district offering more employment opportunities and multiple income sources. Low adaptive capacity clusters were abundant in Rajanpur where respondents had negative loadings on all the principal components. Bahawalpur district lacked any significant adaptive capacity clusters. Spatial analyses can serve as a useful tool for policy makers in identifying the areas requiring government intervention to enhance adaptive capacity. The approach used here could usefully be applied to dryland regions in other parts of the world, and could help guide more targeted efforts to build adaptive capacity