Acorn Biomass and Carbon Stock Variation in Five Oak Species Planted in the National Botanical Garden of Iran

Botanical gardens, as one of the most important urban forests to any region, play an important role in the ecology of human habitats in many ways (e.g., air filtering). The National Botanical Garden of Iran, with an area of 145 ha, includes various woody species with a predominance of oaks (Quercus spp.). The size of acorns, fruits of oaks, varies in different species, which can affect their biomass. The biomass and carbon content of acorn components (endocarp, pericarp, and cupule) of four native oak species (Q. castaneifolia C.A. Mey., Q. libani Oliv., Q. infectoria Oliv., and Q. brantii Lindl.) and one exotic oak species (Q. ilex L.), planted in the National Botanical Garden, were studied to obtain detailed comparative results. Regarding the biomass of acorn components, Q. libani and Q. ilex showed the highest and lowest values among the study species, respectively. The ranges of carbon content of acorn components were 53.5% (pericarp of Q. brantii) to 58% (cupule of Q. castaneifolia). These results confirm the variation of biomass and carbon content of acorn components among the oak species studied.