Aboveground biomass estimation models for Tectona grandis Linn f. plantation in Nnamdi Azikiwe University, Awka, Nigeria

Year 2024, , 244 - 248, 30.09.2024

Onyekachi Chukwu , Ruth Onyekachi Nwene Anabel Anwulika Emebo Abigail Emunu Silas

https://doi.org/10.18182/tjf.1502454

Abstract

Tree biomass is considered a useful indicator of structural and functional attributes of forest ecosystems across a wide range of environmental conditions. The aboveground biomass refers to the living vegetation above the soil, including stem, stump, branches, bark, seeds, and foliage. Teak (Tectona grandis Linn f.) is a popular exotic tree species in Nigeria; it is widely grown in both large scale and small community woodlots. The objective of this study was to develop models for estimation of biomass content of Teak plantation in Nnamdi Azikiwe University, Awka, Nigeria for sustainable management. Data on the diameter at breast height (D) and total height (H) of all teak stands in the plantation were recorded. Non-destructive method using an existing equation was used to estimate the aboveground biomass (AGB) of the individual stands from stump diameter. The Data was subjected to descriptive statistics, bivariate correlation analysis and fitted to six (6) linear regression functions. A total of 295 trees were measured with mean AGB of 18.61 kg. Out of the AGB prediction models developed for the study area, the Semi Log 3 (B5) model had the best predictive ability; with the highest adjusted coefficient of determination (0.984) and the lowest standard error of estimate (0.308), and Akaike information criterion (-690.974). Model B5 (B=0.764+0.764D-0.105lnH) is therefore recommended for future inventory and management of the plantation.

Keywords

Carbon stocks, Forest inventory, Forest modelling, Regression, Tree growth variables

Nnamdi Azikiwe Üniversitesi, Awka, Nijerya'daki Tectona grandis Linn f. plantasyonunun yerüstü biyokütle tahmin modelleri

Abstract

Ağaç biyokütlesi, çok çeşitli çevresel koşullarda orman ekosistemlerinin yapısal ve işlevsel özelliklerinin önemli bir göstergesi olarak kabul edilir. Topraküstü biyokütle (TÜB), gövde, kütük, dal, kabuk, tohum ve yapraklar dahil olmak üzere toprağın üstündeki canlı bitki örtüsünü ifade etmektedir. Tik (Tectona grandis Linn f.), Nijerya'da popüler bir egzotik ağaç türü olup büyük ve küçük topluluklar halinde ormanlık alanlarda yaygın olarak yetiştirilmektedir. Bu çalışmanın amacı, sürdürülebilir yönetim için Nijerya Awka’daki Nnamdi Azikiwe Üniversitesi’nde bulunan tik plantasyonundaki biyokütle miktarının tahmini için modeller geliştirmektir. Plantasyondaki tüm tik ağaçlarının göğüs yüksekliği çapı (DBH), kütük çapı (Ds) ve toplam ağaç boyu (TH) ölçülmüştür. Kütük çapını bir değişken olarak kullanan bir denklem yardımıyla tüm ağaçların topraküstü biyokütle miktarları tahmin edilmiştir. Verilere ait tanımlayıcı istatistikler belirlenmiş, iki değişkenli korelasyon analizi yapılmış ve altı (6) doğrusal regresyon fonksiyonu geliştirilmiştir. Toplamda 295 ağaç ile gerçekleştirilen bu çalışmada, ortalama topraküstü biyokütle miktarı 18.61 kg olarak belirlenmiştir. Çalışma kapsamında geliştirilen modeller arasında en başarılı model, en yüksek düzeltilmiş belirleme katsayısı (0,984), en düşük tahminin standart hatası (0,308) ve en düşük Akaike bilgi kriteri (-690,974) ile Semi Log 3 (B5) modeli olmuştur. Bu nedenle, Model B5, plantasyonun gelecekteki envanteri ve yönetimi için önerilmektedir.

Keywords

Karbon bütçesi, Orman envanteri, Orman modelleme, Regresyon, Ağaç büyüme değişkenleri

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