Impacts of forest management type and season on soil carbon fluxes in Eastern Mau Forest, Kenya

2018 ◽  
Vol 57 (1) ◽  
pp. 113-121 ◽  
Author(s):  
George K. Tarus ◽  
Bernard K. Kirui ◽  
Gilbert Obwoyere
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
George K. Tarus ◽  
Stanley W. Nadir

Mau Forest, a major forest reserve in Kenya, has experienced anthropogenic disturbances through encroachment and forest fires. This study aimed at comparing the soil carbon stocks in different forest management types as well as how seasonal climatic changes influence its dynamics. The study was undertaken in the Eastern Mau block (Sururu) which forms part of the greater Mau Forest Complex. The forest management interventions have been in place for over 15 years with disturbed (fire) natural forest experiencing fires in 2005, 2007, and 2014 while cypress plantations were established in 1994. A nested experimental design was used in data collection, where thirty-two sample plots were nested into four blocks each measuring 100 m2 delineated by forest management types (disturbed by fire, natural forest, undisturbed natural forest, plantation, and glades). In each plot, data on soil carbon stocks, soil bulk density, soil moisture, and temperature were collected for both dry and wet seasons. Data collection was carried out between November 2015 and December 2016. The results indicated that there were no significant differences in the carbon stocks among the forest management types (F4,16 = 0.61, P = 0.613 ). However, seasonal weather changes significantly affected the amount of carbon stocks among the forest management types (F4,16 = 0.61, P > 0.05 ). The undisturbed natural forest had the highest mean soil carbon stocks, while the plantation forest had the lowest as follows: undisturbed natural forest (135.17 ± 35.99.0 Mg·C−ha), disturbed natural forest by fire (134.52 ± 38.11 Mg·C−ha), glades (122.4 ± 64.9 Mg·C−ha), and plantation forest (116.51 ± 39.77 Mg·C−ha). Furthermore, the undisturbed natural forest management had the highest bulk density (0.66 g/cm3), while the disturbed (fire) natural forest had the lowest (0.59 g/cm3). These values were low compared to most normal mineral soils which have a bulk density of between 1.0 g/cm3 and 1.5 g/cm3. There was a significant ( P > 0.01 ) relationship between seasonal weather (temperature) changes and soil carbon stocks under different forest management types with the relationship being stronger in soils under glades (r2 = 0.62) and weak in the undisturbed natural forest (r2 = 0.26). In conclusion, forest disturbances have an impact on soil carbon stocks, and for effective management of forest towards climate stabilization, then disturbance should be minimized if not avoided.


Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.


2009 ◽  
Vol 15 (1) ◽  
pp. 145-155 ◽  
Author(s):  
JIANWU TANG ◽  
PAUL V. BOLSTAD ◽  
JONATHAN G. MARTIN

2017 ◽  
Vol 23 (8) ◽  
pp. 3371-3381 ◽  
Author(s):  
Xiangyin Ni ◽  
Wanqin Yang ◽  
Zemin Qi ◽  
Shu Liao ◽  
Zhenfeng Xu ◽  
...  
Keyword(s):  

Author(s):  
Tarit Kumar Baul ◽  
Avinanda Charkraborty ◽  
Tajkera Akhter Peuly ◽  
Shyamal Karmakar ◽  
Rajasree Nandi ◽  
...  

2019 ◽  
Vol 448 ◽  
pp. 34-47 ◽  
Author(s):  
L.E. Nave ◽  
K. DeLyser ◽  
P.R. Butler-Leopold ◽  
E. Sprague ◽  
J. Daley ◽  
...  

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
João Paulo Gonsiorkiewicz Rigon ◽  
Juliano Carlos Calonego

Abstract Background A field study with the same crop rotations was conducted to test the hypothesis that the soil Carbon fluxes and balances could vary according to the crop species and also mitigate carbon dioxide (CO2) emission. This study aimed to assess the CO2 emission from crop rotations according to C and N inputs from crop residue, the influences on soil organic carbon (SOC) and total soil nitrogen (TN) stocks, identifying the soybean production systems with positive C balance. Triticale (x Triticosecale) or sunflower (Helianthus annuus) are grown in the fall/winter; sunn hemp (Crotalaria juncea), forage sorghum (Sorghum bicolor), pearl millet (Pennisetum glaucum), or fallow are the spring treatments, and soybean as a main crop in summer. Results We found that high C inputs from crop residues modify the C dynamics in crop rotations by reducing the C output (CO2) and increasing C sequestration in the soil. In general, the higher SOC, C stocks, and TN in soil surface were due to higher C and N inputs from sunn hemp or forage sorghum crop residues in spring. These crops also produced lower accumulated CO2 emissions and, when rotating with triticale in the fall-winter season resulted in a positive C balance, making these soybean crop rotations more efficient. Conclusion Our study suggests the ideal crop species choice in a rotation can mitigate the CO2 emissions by increasing C and N input from crop residues and consequently SOC and C stocks. In particular, crop rotation comprises an important tool to achieve a positive C balance, mitigate CO2 emissions and provide an additional ecosystem service to soybean cultivation option.


Sign in / Sign up

Export Citation Format

Share Document