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Impact of Climate Change on Species Distribution and Carbon Storage of Agroforestry Trees on Isolated East African Mountains

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American Journal of Climate Change 2019年第3期8卷 364-386页

作者： Dickens Odeny Faith Karanja Geoffrey Mwachala Petri Pellikka rob marchant Center for Biodiversity National Museums of Kenya Nairobi Kenya Department of Geospatial and Space Technology The University of Nairobi Nairobi Kenya School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science and Technology Nanjing China Earth Change Observation Laboratory Department of Geosciences and Geography University of Helsinki Helsinki Finland Department of Geography and Environment York Institute for Tropical Ecosystem (KITE) University of York York UK

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.

关键词： Agroforestry Carbon Storage Climate Change Albizia Avocado Mango

Comparison and Prediction of the above Ground Carbon Storage in Croplands on the Inhabited Slopes on Mount Kilimanjaro (Tanzania) and the Taita Hills (Kenya)

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Journal of Geographic Information System 2018年第4期10卷 415-438页

作者： Odeny Dickens Karanja Faith Mwachala Geoffrey Pellikka Petri marchant rob Center of Biodiversity National Museums of Keny Nairobi Kenya Department of Geospatial and Space Technology The University of Nairobi Nairobi Kenya Earth Change Observation Laboratory Department of Geosciences and Geography University of Helsinki Helsinki Finland Helsinki Institute of Sustainability Science University of Helsinki Helsinki Finland York Institute for Tropical Ecosystems (KITE) Environment Department University of York York UK

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 res

关键词： Aboveground Carbon Cropland Agroforestry Cropped Land Elevation Gradient

Effect of Soil Properties on Tree Distribution across an Agricultural Landscape on a Tropical Mountain, Tanzania

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Open Journal of Ecology 2016年第5期6卷 264-276页

作者： Mathayo Mpanda Mathew Amos E. Majule Fergus Sinclair rob marchant World Agroforestry Centre (ICRAF) Dar es Salaam Tanzania Institute of Resource Assessment University of Dar es Salaam Tanzania World Agroforestry Centre (ICRAF) Nairobi Kenya York Institute for Tropical Ecosystems Environment Department University of York York UK

Distribution of tree species can result in many factors including environmental variables, biotic interaction and management. Better understanding of these interacting factors is crucial in planning management interventions especially in managed landscapes: this study on the effect of soil properties on tree species distribution in Kilimanjaro, Tanzania will aid in this. Standard tree inventory procedures and soil sampling techniques were used to survey 48 plots from altitudinal level of 680 to 1690 m a.s.l. along 25 km long transect. All trees ≥ 5 cm at DBH were recorded, while soils were sampled from top and subsoils (0 - 20 and 21 - 50 cm depths). Tree species distribution index was assessed through abundance and frequency, while species interaction with environmental variables was assessed using Detrended Correspondence Analysis. Distribution index indicated that 77% of tree species were categorized as rare, while 10% and 13% were categorized as occasional and abundant respectively. Soil organic carbon and moisture content have shown high correlation with tree species (r > 0.8, p < 0.01), while ExMg, soil pH, P, ExCa, ExK, ExNa and bulky density indicated less correlation (r < 0.2, p < 0.001). The DCA-1 axis explained nearly 70% of the relationships between soil properties and tree species distribution: suitability of tree species were influenced by soil properties across the land use systems which exhibited different soil types. Different tree species communities correspond differently with soil properties between the land use systems. Fewer tree species spread in the lowland, which is known to have saline soils. Therefore, despite intensive human management of the landscape, tree species indicated distribution patterns in line with the soil properties.

关键词： Species Communities Trees on Farm Agroforestry Soil and Tree Interactions

Tropical forest canopies and their relationships with climate and disturbance： results from a global dataset of consistent field-based measurements

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Forest Ecosystems 2018年第1期5卷 77-90页

作者： marion pfeifer alemu gonsamo william woodgate luis cayuela andrew r.marshall alicia ledo timothy c.e.paine rob marchant andrew burt kim calders colin courtney-mustaphi aida cuni-sanchez nicolas j.deere dereje denu jose gonzalez de tanago robin hayward alvaro lau manuel j.macía pieter i.olivier petri pellikka hamidu seki deo shirima rebecca trevithick beatrice wedeux charlotte wheeler pantaleo k.t.munishi thomas martin abdul mustari philip j.platts school of natural and environmental sciences newcastle universityUpon TyneNewcastle NE1 7RUUK department of geography and planning university of torontoONCanada land and water commonwealth scientific and industrial research organisationYarralumlaACTAustralia school of mathematical and geospatial sciences rmit universityGPO Box 2476VMelbourneVIC 3001Australia department of biology geologyphysics and inorganic chemistryuniversidad rey juan carlosE-28933 MostolesMadridSpain tropical forest and peopleresearch centre university of the sunshine coastsippy DownsAustralia environment department university of yorkYorkUK flamingo land ltd. MaltonUK the institute of biological and environmental sciences environmental modelling groupuniversity of aberdeenAberdeenUK biological and environmental sciences university of stirlingStirling FK9 4L AUK york institute for tropical ecosystems environment departmentuniversity of yorkYork YO10 5NGUK department of geography university college londonGower StreetLondon WC1E 6BTUK earth observation climate and optical groupnational physical laboratoryHampton RoadTeddingtonMiddlesex TW11 0LWUK department of archaeology and ancient history uppsala universitetP.O.Box 256-751 05 UppsalaSESweden center for macroecology evolution and climateuniversity of copenhagenUniversitetsparken 152100 CopenhagenDKDenmark durrell institute of conservation and ecology(dice) school of anthropology and conservationuniversity of kentCanterbury CT2 7NRUK department of biology college of natural sciencesjimma universityJimmaEthiopia wageningen university&research laboratory of geo-information science and remote sensingDroevendaalsesteeg 36708 PB Wageningenthe Netherlands center for international forestry research(cifor) Situ GedeSindang BarangBogor 16680Indonesia departamento de biología área de botánicauniversidad autónoma de madridcalle Darwin 2-28049 MadridESSpain conservation ecology research unit university of pretoriaHatfieldPretoriaSouth Af

Background： Canopy structure, defined by leaf area index （LAI）, fractional vegetation cover （FCover） and fraction of absorbed photosynthetically active radiation （fAPAR）, regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods： Here, we introduce the Global LAI database： a global dataset of field-based canopy structure measurements spanning tropical forests in four continents （Africa, Asia, Australia and the Americas）. We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results： Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active （within protected areas） and passive measures （through topography）. Once protection and continent effects are accounted for, other anthropogenic measures （e.g. human population） do not improve the model. Conclusions： We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.

关键词： Leaf area index Fractional vegetation cover Fraction of absorbed photosynthetically active radiation,Human population pressure Protected areas Drought Climate change