Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this...Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this area is one such climate event, and it has occurred earlier and with less regularity in recent years. Not all households are able to cope with these changes. This study examines the ability of local farmers to cope with rice insufficiency. This investigation also clarifies household strategies in dealing with the climate event. We randomly interviewed 63 of 95 household heads, and performed a paired sample t test to examine the significance of differences in three household groups between the 2010 normal climate and the 2011 climate event. The groups were categorized according to rice selfsufficiency in 2011: groups I are households with rice self-sufficiency, group II are those facing a rice shortage of up to 3 months, and group III are those with insufficient rice for over 3 months. We also conducted a one-way ANOVA to examine the significance of differences in livelihood strategies among the three groups. We found that the household labor force was the most important factor in enhancing the villagers' ability to deal with the climate event and that the level of impact of that event shaped their coping strategies. Households with substantial labor force had more options for coping strategies than those with smaller ones. The villagers faced different levels of impact and adopted differentcoping strategies accordingly. Non-timber forest product collection was the principle livelihood strategy in response to non-climate factors such as education, access to health services, provision of equipment and clothing, and overcoming the impact of the climate event. Households heavily affected by the early rainy season onset tended to engage in intensive activities such as off-farm activity and outside work, rather than their major livelihood activities in the village(upland crop and livestock production).展开更多
Aims Accurate estimates of bamboo biomass and net primary productivity(NPP)are required to evaluate the carbon sequestration potential of bamboo forests.However,relevant data that are important for climate change miti...Aims Accurate estimates of bamboo biomass and net primary productivity(NPP)are required to evaluate the carbon sequestration potential of bamboo forests.However,relevant data that are important for climate change mitigation,have rarely been collected in regions outside of East Asia and India.Information on seasonal patterns of NPP and its components will enable the quantification of factors that influence the carbon balance in bamboo forests.In this study,we quantified the aboveground biomass(AGB)and aboveground NPP of five major bamboo species in northern Laos using monthly data collected over a 12-month period.Methods All live culms in 10,2 m×2 m plots(for one monopodial bamboo species:Indosasa sinica)and 30 clumps per species(for four sympodial bamboo species:Bambusa tulda,Cephalostachyum virgatum,Dendrocalamus membranaceus and Gigantochloa sp.)were numbered and measured at breast height.We set 10 or 20 litter traps per species to collect litterfall.Censuses of dead and recruited culms and litterfall collection were performed once per month for 12 months.Important Findings The AGB was highest in I.sinica(59.87 Mg ha^(-1))and lowest in C.virgatum(11.54 Mg ha^(-1)),and was mostly below the plausible global range for bamboos(32–256 Mg ha^(-1)).The sympatric distribution of multiple bamboo species at the study sites may have suppressed the AGB in four of the five studied species.The aboveground NPP estimates were between 3.43 and 14.25 Mg ha^(-1) yr^(-1);those for D.membranaceus(8.20 Mg ha^(-1) yr^(-1))and I.sinica(14.25 Mg ha^(-1) yr^(-1))were comparable to mean global estimates for temperate evergreen forests(8.78 Mg ha^(-1) yr^(-1))and tropical moist forests(10.56 Mg ha^(-1) yr^(-1)).High culm recruitment rates(15.20–23.39%yr^(-1))were major contributors to aboveground NPP estimates.Seasonal patterns of aboveground NPP were largely influenced by the phenology of the new culms.In the four sympodial bamboo species,new culms began to emerge following the onset of persistent rainfall,mainly in July and August.However,the sprouting of new culms in the monopodial species I.sinica followed a trend of increasing temperatures,mainly in March and April.Thus,our results indicate that bamboos have considerable potential for sequestering carbon in northern Laos,but that this potential may be affected by climate change.展开更多
基金funded by Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research (Kakenhi), Scientific Research (A)
文摘Climate events pose major challenges to food production and the livelihoods of rural inhabitants in northern Laos, where upland rice using swidden production is an important crop. The onset of the rainy season in this area is one such climate event, and it has occurred earlier and with less regularity in recent years. Not all households are able to cope with these changes. This study examines the ability of local farmers to cope with rice insufficiency. This investigation also clarifies household strategies in dealing with the climate event. We randomly interviewed 63 of 95 household heads, and performed a paired sample t test to examine the significance of differences in three household groups between the 2010 normal climate and the 2011 climate event. The groups were categorized according to rice selfsufficiency in 2011: groups I are households with rice self-sufficiency, group II are those facing a rice shortage of up to 3 months, and group III are those with insufficient rice for over 3 months. We also conducted a one-way ANOVA to examine the significance of differences in livelihood strategies among the three groups. We found that the household labor force was the most important factor in enhancing the villagers' ability to deal with the climate event and that the level of impact of that event shaped their coping strategies. Households with substantial labor force had more options for coping strategies than those with smaller ones. The villagers faced different levels of impact and adopted differentcoping strategies accordingly. Non-timber forest product collection was the principle livelihood strategy in response to non-climate factors such as education, access to health services, provision of equipment and clothing, and overcoming the impact of the climate event. Households heavily affected by the early rainy season onset tended to engage in intensive activities such as off-farm activity and outside work, rather than their major livelihood activities in the village(upland crop and livestock production).
基金supported by the Transnational Doctoral Programs for Leading Professionals,Nagoya University Asian Satellite Campuses Institute(2017-2019).No funding was obtained for this systematic review.
文摘Aims Accurate estimates of bamboo biomass and net primary productivity(NPP)are required to evaluate the carbon sequestration potential of bamboo forests.However,relevant data that are important for climate change mitigation,have rarely been collected in regions outside of East Asia and India.Information on seasonal patterns of NPP and its components will enable the quantification of factors that influence the carbon balance in bamboo forests.In this study,we quantified the aboveground biomass(AGB)and aboveground NPP of five major bamboo species in northern Laos using monthly data collected over a 12-month period.Methods All live culms in 10,2 m×2 m plots(for one monopodial bamboo species:Indosasa sinica)and 30 clumps per species(for four sympodial bamboo species:Bambusa tulda,Cephalostachyum virgatum,Dendrocalamus membranaceus and Gigantochloa sp.)were numbered and measured at breast height.We set 10 or 20 litter traps per species to collect litterfall.Censuses of dead and recruited culms and litterfall collection were performed once per month for 12 months.Important Findings The AGB was highest in I.sinica(59.87 Mg ha^(-1))and lowest in C.virgatum(11.54 Mg ha^(-1)),and was mostly below the plausible global range for bamboos(32–256 Mg ha^(-1)).The sympatric distribution of multiple bamboo species at the study sites may have suppressed the AGB in four of the five studied species.The aboveground NPP estimates were between 3.43 and 14.25 Mg ha^(-1) yr^(-1);those for D.membranaceus(8.20 Mg ha^(-1) yr^(-1))and I.sinica(14.25 Mg ha^(-1) yr^(-1))were comparable to mean global estimates for temperate evergreen forests(8.78 Mg ha^(-1) yr^(-1))and tropical moist forests(10.56 Mg ha^(-1) yr^(-1)).High culm recruitment rates(15.20–23.39%yr^(-1))were major contributors to aboveground NPP estimates.Seasonal patterns of aboveground NPP were largely influenced by the phenology of the new culms.In the four sympodial bamboo species,new culms began to emerge following the onset of persistent rainfall,mainly in July and August.However,the sprouting of new culms in the monopodial species I.sinica followed a trend of increasing temperatures,mainly in March and April.Thus,our results indicate that bamboos have considerable potential for sequestering carbon in northern Laos,but that this potential may be affected by climate change.
