Global food supply has for a long time been regarded as only a problem of food production. Since the turn of the century, however, other aspects have entered the debate, such as improving food quality, changing eating...Global food supply has for a long time been regarded as only a problem of food production. Since the turn of the century, however, other aspects have entered the debate, such as improving food quality, changing eating habits and avoiding food waste. The latter topic has become the subject of attention for the past I0 years and the interest in it has steadily grown. This paper focuses on food waste within the overall context. Apart from the purely quantitative (material) aspects, it draws our attention to the immaterial side of waste, which has to do with our value system. It hopes to sharpen our minds towards a responsible way of dealing with resources展开更多
Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptu...Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were: Ngangao (120 ha), Chawia (86 ha), and Mbololo (185 ha). A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height (DBH) were enumerated and recorded by species. Tree regeneration (seedlings and saplings) was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey's HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land (in Ngango), or the inherent physiology (allelopathy) of some of species repelling the regeneration of others.展开更多
In 2012 and 2013, the Swiss population voted on two separate yet related issues concerning spatial planning. In 2012 a restriction on second homes was introduced into the Constitution, in 2013 referendum the planning ...In 2012 and 2013, the Swiss population voted on two separate yet related issues concerning spatial planning. In 2012 a restriction on second homes was introduced into the Constitution, in 2013 referendum the planning law was revised. Both issues wanted to restrict disproportionate building activities, and were accepted after a heated debate. This outcome mirrors a change in popular attitude towards constructions in the countryside and so-called "cold beds" (second homes used for a short time only), but also towards the disfiguration of the (rural) landscape in general. At the same time it revealed two social rifts: between urban populations (that are increasingly migrating towards rural landscapes) and rural regions that want to obtain a similar level of living as the urban majority, and between lowland and mountain regions. The results of the referenda show that the population is very much concerned about the future of our landscape and environment. The paper discusses the two referenda and their implications for Switzerland in general and for regions that are considered marginal. Its focus lies on the political aspects of the two issues, which not only concern marginality but also are a challenge for national cohesion and direct democracy.展开更多
Background:Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels.However,it may also reduce carbon stocks and habitats for deadwood dependent ...Background:Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels.However,it may also reduce carbon stocks and habitats for deadwood dependent species.Consequently,simple tools for assessing the trade-offs of alternative management practices on forest dynamics and their services to people are needed.The objectives of this study were to combine mapping and simulation modelling to investigate the effects of forest management on ecosystem services related to carbon cycle in the case of bioenergy production;and to evaluate the suitability of this approach for assessing ecosystem services at the landscape level.Stand level simulations of forest growth and carbon budget were combined with extensive multi-source forest inventory data across a southern boreal landscape in Finland.Stochastic changes in the stand age class distribution over the study region were simulated to mimic variation in management regimes.Results:The mapping framework produced reasonable estimates of the effects of forest management on a set of key ecosystem service indicators:the annual carbon stocks and fluxes of forest biomass and soil,timber and energy-wood production and the coarse woody litter production over a simulation period 2012–2100.Regular harvesting,affecting the stand age class distribution,was a key driver of the carbon stock changes at a landscape level.Extracting forest harvest residues in the final felling caused carbon loss from litter and soil,particularly with combined aboveground residue and stump harvesting.It also reduced the annual coarse woody litter production,demonstrating negative impacts on deadwood abundance and,consequently,forest biodiversity.Conclusions:The refined mapping framework was suitable for assessing ecosystem services at the landscape level.The procedure contributes to bridging the gap between ecosystem service mapping and detailed simulation modelling in boreal forests.It allows for visualizing ecosystem services as fine resolution maps to support sustainable land use planning.In the future,more detailed models and a wider variety of ecosystem service indicators could be added to develop the method.展开更多
Mount Kilimanjaro and the Taita Hills are adjacent montane areas that experience similar climate and agricultural activity, but which differ in their geologic history, nature of elevation gradients and cultures. We as...Mount Kilimanjaro and the Taita Hills are adjacent montane areas that experience similar climate and agricultural activity, but which differ in their geologic history, nature of elevation gradients and cultures. We assessed differences in cropland above ground carbon (AGC) between the two sites and against environmental variables. One hectare sampling plots were randomly distributed along elevational gradients stratified by cropland type;AGC was derived from all trees with diameter ≥ 10 cm at breast height in each plot. Predictor variables were physical and edaphic variables and human population. A generalized linear model was used for predicting AGC with AIC used for ranking models. AGC was spatially upscaled in 2 km buffer and visually compared. Kilimanjaro has higher AGC in cropped and agroforestry areas than the Taita Hills, but only significant difference in AGC variation in agroforestry areas (F = 9.36, p = 0.03). AGC in cropped land and agroforestry in Kilimanjaro has significant difference on mean (t = 4.62, p = 0.001) and variation (F = 17.41, p = 0.007). In the Taita Hills, significant difference is observed only on the mean AGC (t = 4.86, p = 0.001). Common tree species that contribute the most to AGC in Kilimanjaro are Albizia gummifera and Persea americana, and in the Taita Hills Grevillea robusta and Mangifera indica. Significant and univariate predictors of AGC in Mount Kilimanjaro are pH (R2 = 0.80, p = 0.00) and EVI (R2 = 0.68, p = 0.00). On Mount Kilimanjaro, the top multivariate model contained SOC, CEC, pH and BLD (R2 = 0.90, p = 0.00), whereas in the Taita Hills, the top multivariate model contained elevation, slope and population (R2 = 0.89, p = 0.00). Despite of the difference in land management history of Mount Kilimanjaro and the Taita Hills, mean of AGC in croplands does not differ significantly. Difference occurs on variation of AGC, type of trees contributing AGC, and environmental variables that explain AGC distribution. The research results provide reference for management of carbon sequestration on inhabited montane areas.展开更多
Changes in climate will affect conditions for species growth and distribution, particularly along elevation gradients, where environmental conditions change abruptly. Agroforestry tree (AGT) species on the densely inh...Changes in climate will affect conditions for species growth and distribution, particularly along elevation gradients, where environmental conditions change abruptly. Agroforestry tree (AGT) species on the densely inhabited slopes of Mount Kilimanjaro and Taita Hills will change their elevation distribution, and associated carbon storage. This study assesses the potential impacts of climate change by modelling species distribution using maximum entropy. We focus on important agroforestry tree species (Albiziagummifera, Mangiferaindica and Perseaamericana) and projected climate variables under IPCC-AR5 RCP 4.5 and 8.5 for the mid-century (2055) and late century (2085). Results show differential response: downward migration for M. indica on the slopes of Mount Kilimanjaro is contrasted with Avocado that will shift upslope on the Taita Hills under RCP 8.5. Perseaamericana will lose suitable habitat on Kilimanjaro whereas M. indica will expand habitat suitability. Potential increase in suitable areas for agroforestry species in Taita Hills will occur except for Albizia and Mango which will potentially decrease in suitable areas under RCP 4.5 for period 2055. Shift in minimum elevation range will affect species suitable areas ultimately influencing AGC on the slopes of Mount Kilimanjaro and Taita Hills. The AGC for agroforestry species will decrease on the slopes of Mount Kilimanjaro but AGC for Mango will increase under RCP 8.5 for period 2055 and 2085. In Taita Hills, AGC will remain relatively stable for A. gummifera and P. americana under RCP 8.5 for period 2055 and 2085 but decrease in AGC will occur for M. indica under projected climate change. Climate change will affect AGT species and the amount of carbon stored differently between the sites. Such insight can inform AGT species choice, and conservation and support development by improving carbon sequestration on sites and reliable food production.展开更多
Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature (SST) pattern, such as the Pacific Decadal Oscillation (PDO). The PDO may be ...Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature (SST) pattern, such as the Pacific Decadal Oscillation (PDO). The PDO may be associated with the North Pacific branch of the Thermohaline Circulation (THC). Great earthquakes (M 〉8), particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.展开更多
In this study,we report systematically field observations,geochronology,whole-rock geochemistry and Sr-Nd-Hf isotopic dataset on the various types of magmatic rocks collected from the Zedang area.Chemically,the diabas...In this study,we report systematically field observations,geochronology,whole-rock geochemistry and Sr-Nd-Hf isotopic dataset on the various types of magmatic rocks collected from the Zedang area.Chemically,the diabase and gabbro have a low-K calc-alkaline affinity,whereas the basalt and plagiogranite have medium to high-K calc-alkaline characteristics.In addition,the basalts are highly enriched in light rare earth elements(LREE)and large ion lithophile elements(LILE),but strongly depleted in high strength field elements(HFSE),indicating that their magma source probably was derived from a subduction-or arc-related setting.In contrast,both the gabbro and diabase mainly demonstrate an N-MORB-like affinity consistent with normal mid-oceanic ridge basalt(N-MORB)origin.The zircon U-Pb dating results suggest that the basalts were crystallized earlier at ca.158–161 Ma(Oxfordian stage),but the gabbro was crystallized at ca.131 Ma(Hauterivian stage of Early Cretaceous).The zircon U-Pb dating results correspond with the field observations that the veins of gabbro intruded basalt.Furthermore,the plagiogranite has a weighted mean age of ca.160 Ma(MSWD=2.1)consistent with the basalt within the uncertainty.The basalt and the plagiogranite have significantly positiveεHf(t)values(+5.8 to+15.6 and+8.6 to+16.1,respectively),suggesting that they were originated from partial melting of a depleted source.However,basalt and plagiogranite are characterized by the wide variations ofεHf(t)values indicating minor amounts of exotic crustal material input during the later magma evolution.Additionally,the basalt shows duplex geochemical features of island-arc and mid-oceanic ridge basalt,corresponding to the supra-subduction zone-(SSZ)type affinity.To sum up,two distinct magmatic events identified in this study probably suggest an intra-oceanic arc system existing in the Zedang area during the Late Jurassic,but the intra-oceanic arc subduction extinguished in the Early Cretaceous as suggested by the N-MORB-like gabbro and diabase.Integrated with regional background and different rock types,as well as geochemical features,we conclude that intra-oceanic arc subduction setting developed during the Late Jurassic in the Zedang area,southern Tibet.展开更多
Dehydration melting of metasupracrustal rocks at mid-to deep-crustal levels can generate water undersaturated granitic melt.In this study,we evaluate the potential of~1.89–1.88 Ga metasupracrustal rocks of the Precam...Dehydration melting of metasupracrustal rocks at mid-to deep-crustal levels can generate water undersaturated granitic melt.In this study,we evaluate the potential of~1.89–1.88 Ga metasupracrustal rocks of the Precambrian of southern Finland as source rocks for the 1.86–1.79 Ga late-orogenic leucogranites in the region,using the Rhyolite-MELTS approach.Melt close in composition to leucogranite is produced over a range of realistic pressures(5 to 8 kbar)and temperatures(800 to 850℃),at 20%–30%of partial melting,allowing separation of melt from unmelted residue.The solid residue is a dry,enderbitic to charnoenderbitic ganulite depleted in incompatible components,and will only yield further melt above 1000–1050℃,when rapidly increasing fractions of increasingly calcic(granodioritic to tonalitic)melts are formed.The solid residue after melt extraction is incapable of producing syenogranitic magmas similar to the Mid-Proterozoic,A-type rapakivi granites on further heating.The granitic fraction of the syenogranitic rapakivi complexes must thus have been formed by a different chain of processes,involving mantle-derived mafic melts and melts from crustal rock types not conditioned by the preceding late-orogenic Svecofennian anatexis.展开更多
Kaapvaal lamproites(aka orangeites)are a group of volatile-rich(H_(2)O,CO_(2)),micaceous,ultrapotassic igneous rocks that are unique to the Kaapvaal craton in southern Africa.However,the composition of the melts that ...Kaapvaal lamproites(aka orangeites)are a group of volatile-rich(H_(2)O,CO_(2)),micaceous,ultrapotassic igneous rocks that are unique to the Kaapvaal craton in southern Africa.However,the composition of the melts that give rise to these rocks remains poorly understood due to overprinting effects of contamination by mantle and crustal material,volatile exsolution,fractional crystallisation and post-magmatic alteration.Consequently,this lack of reliable data on the initial composition of the Kaapvaal lamproite melts hampers our understanding of their source,petrogenesis and ascent mechanisms.Olivine is a common mineral comprising the Kaapvaal lamproites that has both xenocrystic(i.e.,mantle)and magmatic origins.Multiphase inclusions(melt/fluid)entrapped within olivine have been consistently demonstrated as an effective tool for gaining fundamental insights into the composition and evolution of melts that produce both kimberlites and lamproites,prior to processes,such as eruption,devolatization and syn-/post-magmatic alteration.In this study,multiphase inclusions of both secondary and pseudosecondary origin hosted in olivine from a Kaapvaal lamproite(Silvery Home,South Africa)provide novel insights into the composition of the melt(s)that initially transported olivine to the surface and then crystallised after emplacement to form the lamproite groundmass.The inclusions in our study contain daughter mineral assemblages consisting of diverse Ca-Mg carbonates,including K-,Na-,Ba-,and Sr-bearing varieties,moderate K-rich silicates(phlogopite,tetraferriphlogopite),and subordinate oxides,phosphates,sulphides,sulphates,and halides.Based on these daughter mineral assemblages,we suggest that the composition of the melt entrapped by olivine was SiO_(2)-poor,Ca-Mg carbonate-rich and contained elevated concentrations of K,Na,Ba,Sr,P and Cl.The mineral and reconstructed melt compositions are in stark contrast to the mineral association of the groundmass and the bulk-rock composition of the Silvery Home lamproite,respectively.We suggest that alkali-/alkali-earth carbonates,phosphates,sulphides,sulphates,and halides represented a potentially significant,or even dominant,component of the melt that crystallised the Silvery Home lamproite but were likely removed by degassing and/or interaction with syn-/post-magmatic fluids.We show that olivine-hosted multiphase inclusions from the Silvery Home lamproite share many compositional similarities to melt inclusions hosted in olivine from kimberlites but are distinct from‘classic’cratonic olivine lamproites worldwide.展开更多
Cryophenological records (i.e. observational series of freeze and breakup dates of ice) are of great importance when assessing the environmental variations in cold regions. Here we employed the extraordinarily long ...Cryophenological records (i.e. observational series of freeze and breakup dates of ice) are of great importance when assessing the environmental variations in cold regions. Here we employed the extraordinarily long observational records of river ice breakup dates and air temperatures in northern Fennoscandia to examine their interrelations since 1802. Historical observations, along with modern data, comprise the informational setting for this analysis carried out using t-test. Temperature history of April-May season was used as cli- matic counterpart for the breakup timings. Both records (temperature and breakup) showed seven sub-periods during which their local means were distinctly different relative to preced- ing and subsequent sub-periods. The starting and ending years of these sub-periods oc- curred in temporal agreement. The main findings of this study are summarized as follows: (1) the synchrony between the temperature and river ice breakup records ruled out the possibility that the changes would have occurred due to quality of the historical series (i.e. inhomoge- neity problems often linked to historical time-series); (2) the studied records agreed to show lower spring temperatures and later river ice breakups during the 19th century, in comparison to the 20th century conditions, evidencing the prevalence of cooler spring temperatures in the study region, in agreement with the concept of the Little Ice Age (1570-1900) climate in North-West Europe; (3) the most recent sub-period demonstrate the highest spring tem- peratures with concomitantly earliest river ice breakups, showing the relative warmth of the current springtime climate in the study region in the context of the past two centuries; (4) the effects of anthropogenic changes in the river environment (e.g. construction and demolition of dams) during the 20th century should be considered for non-climatic variations in the breakup records; (5) this study emphasizes the importance of multi-centurial (i.e. historical) cryo- phenological information for highly interesting viewpoints of climate and environmental his- tory.展开更多
We outline here an approach for understanding the biology of climate change,one that integrates data at multiple spatial and temporal scales.Taxon-free trait analysis,or“ecometrics,”is based on the idea that the dis...We outline here an approach for understanding the biology of climate change,one that integrates data at multiple spatial and temporal scales.Taxon-free trait analysis,or“ecometrics,”is based on the idea that the distribution in a community of ecomorphological traits such as tooth structure,limb proportions,body mass,leaf shape,incubation temperature,claw shape,any aspect of anatomy or physiology can be measured across some subset of the organisms in a community.Regardless of temporal or spatial scale,traits are the means by which organisms interact with their environment,biotic and abiotic.Ecometrics measures these interactions by focusing on traits which are easily measurable,whose structure is closely related to their function,and whose function interacts directly with local environment.Ecometric trait distributions are thus a comparatively universal metric for exploring systems dynamics at all scales.The main challenge now is to move beyond investigating how future climate change will affect the distribution of organisms and how it will impact ecosystem services and to shift the perspective to ask how biotic systems interact with changing climate in general,and how climate change affects the interactions within and between the components of the whole biotic-physical system.We believe that it is possible to provide believable,quantitative answers to these questions.Because of this we have initiated an IUBS program iCCB(integrative Climate Change Biology).展开更多
文摘Global food supply has for a long time been regarded as only a problem of food production. Since the turn of the century, however, other aspects have entered the debate, such as improving food quality, changing eating habits and avoiding food waste. The latter topic has become the subject of attention for the past I0 years and the interest in it has steadily grown. This paper focuses on food waste within the overall context. Apart from the purely quantitative (material) aspects, it draws our attention to the immaterial side of waste, which has to do with our value system. It hopes to sharpen our minds towards a responsible way of dealing with resources
基金supported by the Academy of Finland for the funding of the TAITATOO project
文摘Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were: Ngangao (120 ha), Chawia (86 ha), and Mbololo (185 ha). A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height (DBH) were enumerated and recorded by species. Tree regeneration (seedlings and saplings) was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey's HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land (in Ngango), or the inherent physiology (allelopathy) of some of species repelling the regeneration of others.
文摘In 2012 and 2013, the Swiss population voted on two separate yet related issues concerning spatial planning. In 2012 a restriction on second homes was introduced into the Constitution, in 2013 referendum the planning law was revised. Both issues wanted to restrict disproportionate building activities, and were accepted after a heated debate. This outcome mirrors a change in popular attitude towards constructions in the countryside and so-called "cold beds" (second homes used for a short time only), but also towards the disfiguration of the (rural) landscape in general. At the same time it revealed two social rifts: between urban populations (that are increasingly migrating towards rural landscapes) and rural regions that want to obtain a similar level of living as the urban majority, and between lowland and mountain regions. The results of the referenda show that the population is very much concerned about the future of our landscape and environment. The paper discusses the two referenda and their implications for Switzerland in general and for regions that are considered marginal. Its focus lies on the political aspects of the two issues, which not only concern marginality but also are a challenge for national cohesion and direct democracy.
基金supported by Maj and Tor Nessling Foundation through the grant “Coupling carbon sequestration of forests and croplands with ecosystem service assessments”(decision No. 201700251)LIFE+financial instrument of the European Union (LIFE12 ENV/FI/000409, MONIMET)+1 种基金the Academy of Finland Strategic Research Council project (SRC 2017/312559 IBC-CARBON)supported by the Academy of Finland through the grant “Trade-offs and synergies in land-based climate change mitigation and biodiversity conservation”(decision No. 322066)
文摘Background:Increasing the use of forest harvest residues for bioenergy production reduces greenhouse emissions from the use of fossil fuels.However,it may also reduce carbon stocks and habitats for deadwood dependent species.Consequently,simple tools for assessing the trade-offs of alternative management practices on forest dynamics and their services to people are needed.The objectives of this study were to combine mapping and simulation modelling to investigate the effects of forest management on ecosystem services related to carbon cycle in the case of bioenergy production;and to evaluate the suitability of this approach for assessing ecosystem services at the landscape level.Stand level simulations of forest growth and carbon budget were combined with extensive multi-source forest inventory data across a southern boreal landscape in Finland.Stochastic changes in the stand age class distribution over the study region were simulated to mimic variation in management regimes.Results:The mapping framework produced reasonable estimates of the effects of forest management on a set of key ecosystem service indicators:the annual carbon stocks and fluxes of forest biomass and soil,timber and energy-wood production and the coarse woody litter production over a simulation period 2012–2100.Regular harvesting,affecting the stand age class distribution,was a key driver of the carbon stock changes at a landscape level.Extracting forest harvest residues in the final felling caused carbon loss from litter and soil,particularly with combined aboveground residue and stump harvesting.It also reduced the annual coarse woody litter production,demonstrating negative impacts on deadwood abundance and,consequently,forest biodiversity.Conclusions:The refined mapping framework was suitable for assessing ecosystem services at the landscape level.The procedure contributes to bridging the gap between ecosystem service mapping and detailed simulation modelling in boreal forests.It allows for visualizing ecosystem services as fine resolution maps to support sustainable land use planning.In the future,more detailed models and a wider variety of ecosystem service indicators could be added to develop the method.
文摘Mount Kilimanjaro and the Taita Hills are adjacent montane areas that experience similar climate and agricultural activity, but which differ in their geologic history, nature of elevation gradients and cultures. We assessed differences in cropland above ground carbon (AGC) between the two sites and against environmental variables. One hectare sampling plots were randomly distributed along elevational gradients stratified by cropland type;AGC was derived from all trees with diameter ≥ 10 cm at breast height in each plot. Predictor variables were physical and edaphic variables and human population. A generalized linear model was used for predicting AGC with AIC used for ranking models. AGC was spatially upscaled in 2 km buffer and visually compared. Kilimanjaro has higher AGC in cropped and agroforestry areas than the Taita Hills, but only significant difference in AGC variation in agroforestry areas (F = 9.36, p = 0.03). AGC in cropped land and agroforestry in Kilimanjaro has significant difference on mean (t = 4.62, p = 0.001) and variation (F = 17.41, p = 0.007). In the Taita Hills, significant difference is observed only on the mean AGC (t = 4.86, p = 0.001). Common tree species that contribute the most to AGC in Kilimanjaro are Albizia gummifera and Persea americana, and in the Taita Hills Grevillea robusta and Mangifera indica. Significant and univariate predictors of AGC in Mount Kilimanjaro are pH (R2 = 0.80, p = 0.00) and EVI (R2 = 0.68, p = 0.00). On Mount Kilimanjaro, the top multivariate model contained SOC, CEC, pH and BLD (R2 = 0.90, p = 0.00), whereas in the Taita Hills, the top multivariate model contained elevation, slope and population (R2 = 0.89, p = 0.00). Despite of the difference in land management history of Mount Kilimanjaro and the Taita Hills, mean of AGC in croplands does not differ significantly. Difference occurs on variation of AGC, type of trees contributing AGC, and environmental variables that explain AGC distribution. The research results provide reference for management of carbon sequestration on inhabited montane areas.
文摘Changes in climate will affect conditions for species growth and distribution, particularly along elevation gradients, where environmental conditions change abruptly. Agroforestry tree (AGT) species on the densely inhabited slopes of Mount Kilimanjaro and Taita Hills will change their elevation distribution, and associated carbon storage. This study assesses the potential impacts of climate change by modelling species distribution using maximum entropy. We focus on important agroforestry tree species (Albiziagummifera, Mangiferaindica and Perseaamericana) and projected climate variables under IPCC-AR5 RCP 4.5 and 8.5 for the mid-century (2055) and late century (2085). Results show differential response: downward migration for M. indica on the slopes of Mount Kilimanjaro is contrasted with Avocado that will shift upslope on the Taita Hills under RCP 8.5. Perseaamericana will lose suitable habitat on Kilimanjaro whereas M. indica will expand habitat suitability. Potential increase in suitable areas for agroforestry species in Taita Hills will occur except for Albizia and Mango which will potentially decrease in suitable areas under RCP 4.5 for period 2055. Shift in minimum elevation range will affect species suitable areas ultimately influencing AGC on the slopes of Mount Kilimanjaro and Taita Hills. The AGC for agroforestry species will decrease on the slopes of Mount Kilimanjaro but AGC for Mango will increase under RCP 8.5 for period 2055 and 2085. In Taita Hills, AGC will remain relatively stable for A. gummifera and P. americana under RCP 8.5 for period 2055 and 2085 but decrease in AGC will occur for M. indica under projected climate change. Climate change will affect AGT species and the amount of carbon stored differently between the sites. Such insight can inform AGT species choice, and conservation and support development by improving carbon sequestration on sites and reliable food production.
基金funded by the Nordic Top-level Research Initiative CRAICC(Cryosphere-Atmosphere Interactions in A Changing Arctic Climate)the National Natural Science Foundation of China(Nos.41001115 and 41210002)
文摘Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature (SST) pattern, such as the Pacific Decadal Oscillation (PDO). The PDO may be associated with the North Pacific branch of the Thermohaline Circulation (THC). Great earthquakes (M 〉8), particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.
基金financially co-supported by the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources (Nos. J1901-7,J1901-16)the State Scholarship Fund (No. 201904180031)+4 种基金the National Key Research and Development Project of China (No. 2016YFC0600310)the 2nd Tibetan Plateau Scientific Expedition (No. 2019QZKK0802)the National Natural Science Foundation of China (Nos. 41672046,41641015,41762005,41720104009,41703036)the China Geological Survey (No. DD201190060)the International Geological Correlation Project (No. IGCP-649)
文摘In this study,we report systematically field observations,geochronology,whole-rock geochemistry and Sr-Nd-Hf isotopic dataset on the various types of magmatic rocks collected from the Zedang area.Chemically,the diabase and gabbro have a low-K calc-alkaline affinity,whereas the basalt and plagiogranite have medium to high-K calc-alkaline characteristics.In addition,the basalts are highly enriched in light rare earth elements(LREE)and large ion lithophile elements(LILE),but strongly depleted in high strength field elements(HFSE),indicating that their magma source probably was derived from a subduction-or arc-related setting.In contrast,both the gabbro and diabase mainly demonstrate an N-MORB-like affinity consistent with normal mid-oceanic ridge basalt(N-MORB)origin.The zircon U-Pb dating results suggest that the basalts were crystallized earlier at ca.158–161 Ma(Oxfordian stage),but the gabbro was crystallized at ca.131 Ma(Hauterivian stage of Early Cretaceous).The zircon U-Pb dating results correspond with the field observations that the veins of gabbro intruded basalt.Furthermore,the plagiogranite has a weighted mean age of ca.160 Ma(MSWD=2.1)consistent with the basalt within the uncertainty.The basalt and the plagiogranite have significantly positiveεHf(t)values(+5.8 to+15.6 and+8.6 to+16.1,respectively),suggesting that they were originated from partial melting of a depleted source.However,basalt and plagiogranite are characterized by the wide variations ofεHf(t)values indicating minor amounts of exotic crustal material input during the later magma evolution.Additionally,the basalt shows duplex geochemical features of island-arc and mid-oceanic ridge basalt,corresponding to the supra-subduction zone-(SSZ)type affinity.To sum up,two distinct magmatic events identified in this study probably suggest an intra-oceanic arc system existing in the Zedang area during the Late Jurassic,but the intra-oceanic arc subduction extinguished in the Early Cretaceous as suggested by the N-MORB-like gabbro and diabase.Integrated with regional background and different rock types,as well as geochemical features,we conclude that intra-oceanic arc subduction setting developed during the Late Jurassic in the Zedang area,southern Tibet.
文摘Dehydration melting of metasupracrustal rocks at mid-to deep-crustal levels can generate water undersaturated granitic melt.In this study,we evaluate the potential of~1.89–1.88 Ga metasupracrustal rocks of the Precambrian of southern Finland as source rocks for the 1.86–1.79 Ga late-orogenic leucogranites in the region,using the Rhyolite-MELTS approach.Melt close in composition to leucogranite is produced over a range of realistic pressures(5 to 8 kbar)and temperatures(800 to 850℃),at 20%–30%of partial melting,allowing separation of melt from unmelted residue.The solid residue is a dry,enderbitic to charnoenderbitic ganulite depleted in incompatible components,and will only yield further melt above 1000–1050℃,when rapidly increasing fractions of increasingly calcic(granodioritic to tonalitic)melts are formed.The solid residue after melt extraction is incapable of producing syenogranitic magmas similar to the Mid-Proterozoic,A-type rapakivi granites on further heating.The granitic fraction of the syenogranitic rapakivi complexes must thus have been formed by a different chain of processes,involving mantle-derived mafic melts and melts from crustal rock types not conditioned by the preceding late-orogenic Svecofennian anatexis.
基金funded by the K.H.Renlund Foundation(Finland)and Future Making Fellowship(University of Adelaide)AVG and AAT were supported by the state assignment of IGM SB RAS(No.122041400157-9).
文摘Kaapvaal lamproites(aka orangeites)are a group of volatile-rich(H_(2)O,CO_(2)),micaceous,ultrapotassic igneous rocks that are unique to the Kaapvaal craton in southern Africa.However,the composition of the melts that give rise to these rocks remains poorly understood due to overprinting effects of contamination by mantle and crustal material,volatile exsolution,fractional crystallisation and post-magmatic alteration.Consequently,this lack of reliable data on the initial composition of the Kaapvaal lamproite melts hampers our understanding of their source,petrogenesis and ascent mechanisms.Olivine is a common mineral comprising the Kaapvaal lamproites that has both xenocrystic(i.e.,mantle)and magmatic origins.Multiphase inclusions(melt/fluid)entrapped within olivine have been consistently demonstrated as an effective tool for gaining fundamental insights into the composition and evolution of melts that produce both kimberlites and lamproites,prior to processes,such as eruption,devolatization and syn-/post-magmatic alteration.In this study,multiphase inclusions of both secondary and pseudosecondary origin hosted in olivine from a Kaapvaal lamproite(Silvery Home,South Africa)provide novel insights into the composition of the melt(s)that initially transported olivine to the surface and then crystallised after emplacement to form the lamproite groundmass.The inclusions in our study contain daughter mineral assemblages consisting of diverse Ca-Mg carbonates,including K-,Na-,Ba-,and Sr-bearing varieties,moderate K-rich silicates(phlogopite,tetraferriphlogopite),and subordinate oxides,phosphates,sulphides,sulphates,and halides.Based on these daughter mineral assemblages,we suggest that the composition of the melt entrapped by olivine was SiO_(2)-poor,Ca-Mg carbonate-rich and contained elevated concentrations of K,Na,Ba,Sr,P and Cl.The mineral and reconstructed melt compositions are in stark contrast to the mineral association of the groundmass and the bulk-rock composition of the Silvery Home lamproite,respectively.We suggest that alkali-/alkali-earth carbonates,phosphates,sulphides,sulphates,and halides represented a potentially significant,or even dominant,component of the melt that crystallised the Silvery Home lamproite but were likely removed by degassing and/or interaction with syn-/post-magmatic fluids.We show that olivine-hosted multiphase inclusions from the Silvery Home lamproite share many compositional similarities to melt inclusions hosted in olivine from kimberlites but are distinct from‘classic’cratonic olivine lamproites worldwide.
基金Academy of Finland,No.251441The Project of Ministry of Finance,No.GYHY200706005Kone Foundation(Finland)
文摘Cryophenological records (i.e. observational series of freeze and breakup dates of ice) are of great importance when assessing the environmental variations in cold regions. Here we employed the extraordinarily long observational records of river ice breakup dates and air temperatures in northern Fennoscandia to examine their interrelations since 1802. Historical observations, along with modern data, comprise the informational setting for this analysis carried out using t-test. Temperature history of April-May season was used as cli- matic counterpart for the breakup timings. Both records (temperature and breakup) showed seven sub-periods during which their local means were distinctly different relative to preced- ing and subsequent sub-periods. The starting and ending years of these sub-periods oc- curred in temporal agreement. The main findings of this study are summarized as follows: (1) the synchrony between the temperature and river ice breakup records ruled out the possibility that the changes would have occurred due to quality of the historical series (i.e. inhomoge- neity problems often linked to historical time-series); (2) the studied records agreed to show lower spring temperatures and later river ice breakups during the 19th century, in comparison to the 20th century conditions, evidencing the prevalence of cooler spring temperatures in the study region, in agreement with the concept of the Little Ice Age (1570-1900) climate in North-West Europe; (3) the most recent sub-period demonstrate the highest spring tem- peratures with concomitantly earliest river ice breakups, showing the relative warmth of the current springtime climate in the study region in the context of the past two centuries; (4) the effects of anthropogenic changes in the river environment (e.g. construction and demolition of dams) during the 20th century should be considered for non-climatic variations in the breakup records; (5) this study emphasizes the importance of multi-centurial (i.e. historical) cryo- phenological information for highly interesting viewpoints of climate and environmental his- tory.
基金the ISZS international research program Biological Consequences of Global Change(BCGC)sponsored by Bureau of International Cooperation,Chinese Academy of Sciences(GJHZ200810).
文摘We outline here an approach for understanding the biology of climate change,one that integrates data at multiple spatial and temporal scales.Taxon-free trait analysis,or“ecometrics,”is based on the idea that the distribution in a community of ecomorphological traits such as tooth structure,limb proportions,body mass,leaf shape,incubation temperature,claw shape,any aspect of anatomy or physiology can be measured across some subset of the organisms in a community.Regardless of temporal or spatial scale,traits are the means by which organisms interact with their environment,biotic and abiotic.Ecometrics measures these interactions by focusing on traits which are easily measurable,whose structure is closely related to their function,and whose function interacts directly with local environment.Ecometric trait distributions are thus a comparatively universal metric for exploring systems dynamics at all scales.The main challenge now is to move beyond investigating how future climate change will affect the distribution of organisms and how it will impact ecosystem services and to shift the perspective to ask how biotic systems interact with changing climate in general,and how climate change affects the interactions within and between the components of the whole biotic-physical system.We believe that it is possible to provide believable,quantitative answers to these questions.Because of this we have initiated an IUBS program iCCB(integrative Climate Change Biology).