Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya
Tropical landscapes comprise a variety of land cover (LC) types with characteristic canopy structure and tree species. Depending on the LC type, large-diameter trees and certain tree species can contribute disproportionately to aboveground biomass (AGB), and these patterns are not described at lands...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
|
| Series: | Forests |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1999-4907/14/3/642 |
| _version_ | 1797611642278641664 |
|---|---|
| author | Edward Amara Hari Adhikari James M. Mwamodenyi Petri K. E. Pellikka Janne Heiskanen |
| author_facet | Edward Amara Hari Adhikari James M. Mwamodenyi Petri K. E. Pellikka Janne Heiskanen |
| author_sort | Edward Amara |
| collection | DOAJ |
| description | Tropical landscapes comprise a variety of land cover (LC) types with characteristic canopy structure and tree species. Depending on the LC type, large-diameter trees and certain tree species can contribute disproportionately to aboveground biomass (AGB), and these patterns are not described at landscape-level in LC type specific studies. Therefore, we investigated the impact of large trees and tree species on AGB across a range of LC types in Taita Hills, Kenya. Data included 239 field plots from seven LC types: Montane forest, Plantation forest, Mixed forest, Riverine forest, Bushland, Grassland, and Cropland and homestead. Our results show that the contribution of large trees (DBH > 60 cm) on AGB was greatest in Riverine forest, Montane forest and Mixed forest (34–87%). Large trees were also common in Plantation forests and Cropland and homestead. Small trees (DBH < 20 cm) covered less than 10% of the total AGB in all forest types. In Grassland, and Cropland and homestead, smaller DBH classes made a greater contribution. Bushland differed from other classes as large trees were rare. Furthermore, the results show that each LC type had characteristic species with high AGB. In the Montane and Mixed forest, <i>Albizia gummifera</i> contributed 21.1% and 18.3% to AGB, respectively. <i>Eucalyptus</i> spp., exotic species planted in the area, were important in Mixed and Plantation forests. <i>Newtonia hildebrandtii</i> was the most important species in Riverine forests. In Bushland, <i>Acacia mearnsii</i>, species with invasive character, was abundant among trees with DBH < 30 cm. <i>Vachellia tortillis</i>, a common species in savannahs of East Africa, made the largest contribution in Grassland. Finally, in Cropland and homestead, <i>Grevillea robusta</i> was the most important species (>25% of AGB). Our results highlight the importance of conserving large trees and certain species to retain AGB stocks in the landscape. Furthermore, the results demonstrate that exotic tree species, even though invasive, can have large contribution to AGB. |
| first_indexed | 2024-03-11T06:30:38Z |
| format | Article |
| id | doaj.art-02510a78c08b4c709689a74b478b73a0 |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-11T06:30:38Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-02510a78c08b4c709689a74b478b73a02023-11-17T11:11:25ZengMDPI AGForests1999-49072023-03-0114364210.3390/f14030642Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern KenyaEdward Amara0Hari Adhikari1James M. Mwamodenyi2Petri K. E. Pellikka3Janne Heiskanen4Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, FinlandAFRY Management Consulting Oy, Jaakonkatu 3, FI-01620 Vantaa, FinlandDepartment of Geosciences and Geography, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, FinlandDepartment of Geosciences and Geography, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, FinlandDepartment of Geosciences and Geography, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, FinlandTropical landscapes comprise a variety of land cover (LC) types with characteristic canopy structure and tree species. Depending on the LC type, large-diameter trees and certain tree species can contribute disproportionately to aboveground biomass (AGB), and these patterns are not described at landscape-level in LC type specific studies. Therefore, we investigated the impact of large trees and tree species on AGB across a range of LC types in Taita Hills, Kenya. Data included 239 field plots from seven LC types: Montane forest, Plantation forest, Mixed forest, Riverine forest, Bushland, Grassland, and Cropland and homestead. Our results show that the contribution of large trees (DBH > 60 cm) on AGB was greatest in Riverine forest, Montane forest and Mixed forest (34–87%). Large trees were also common in Plantation forests and Cropland and homestead. Small trees (DBH < 20 cm) covered less than 10% of the total AGB in all forest types. In Grassland, and Cropland and homestead, smaller DBH classes made a greater contribution. Bushland differed from other classes as large trees were rare. Furthermore, the results show that each LC type had characteristic species with high AGB. In the Montane and Mixed forest, <i>Albizia gummifera</i> contributed 21.1% and 18.3% to AGB, respectively. <i>Eucalyptus</i> spp., exotic species planted in the area, were important in Mixed and Plantation forests. <i>Newtonia hildebrandtii</i> was the most important species in Riverine forests. In Bushland, <i>Acacia mearnsii</i>, species with invasive character, was abundant among trees with DBH < 30 cm. <i>Vachellia tortillis</i>, a common species in savannahs of East Africa, made the largest contribution in Grassland. Finally, in Cropland and homestead, <i>Grevillea robusta</i> was the most important species (>25% of AGB). Our results highlight the importance of conserving large trees and certain species to retain AGB stocks in the landscape. Furthermore, the results demonstrate that exotic tree species, even though invasive, can have large contribution to AGB.https://www.mdpi.com/1999-4907/14/3/642landscapeaboveground biomasstree speciesland coverimportant value index |
| spellingShingle | Edward Amara Hari Adhikari James M. Mwamodenyi Petri K. E. Pellikka Janne Heiskanen Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya Forests landscape aboveground biomass tree species land cover important value index |
| title | Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya |
| title_full | Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya |
| title_fullStr | Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya |
| title_full_unstemmed | Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya |
| title_short | Contribution of Tree Size and Species on Aboveground Biomass across Land Cover Types in the Taita Hills, Southern Kenya |
| title_sort | contribution of tree size and species on aboveground biomass across land cover types in the taita hills southern kenya |
| topic | landscape aboveground biomass tree species land cover important value index |
| url | https://www.mdpi.com/1999-4907/14/3/642 |
| work_keys_str_mv | AT edwardamara contributionoftreesizeandspeciesonabovegroundbiomassacrosslandcovertypesinthetaitahillssouthernkenya AT hariadhikari contributionoftreesizeandspeciesonabovegroundbiomassacrosslandcovertypesinthetaitahillssouthernkenya AT jamesmmwamodenyi contributionoftreesizeandspeciesonabovegroundbiomassacrosslandcovertypesinthetaitahillssouthernkenya AT petrikepellikka contributionoftreesizeandspeciesonabovegroundbiomassacrosslandcovertypesinthetaitahillssouthernkenya AT janneheiskanen contributionoftreesizeandspeciesonabovegroundbiomassacrosslandcovertypesinthetaitahillssouthernkenya |