Resource reservation is one of the effective solutions in guaranteeing the quality-of-service (QoS) in communication networks. In this paper, we propose a novel resource reservation scheme for dynamically managing the bandwidth resources in IEEE 802.11e-based wireless local area networks (WLANs). The proposed solution consists of two components namely (i) dynamic medium access control (MAC) scheduler and (ii) adaptive admission control algorithm. Once resources occupied by certain stations become idle due to the end of QoS data session, the proposed MAC scheduler will either release the resources to the non-real-time traffic flows (NRTTFs) or re-allocate them to other real-time traffic flows (RTTFs) which require dedicated resources. The re-allocating process is implemented with the support of the novel adaptive admission control algorithm (AACA) that decides which RTTF can gain access to the available resources in a distributed manner. Evaluation of our proposed scheme is conducted in several scenarios through extensive ns2 simulation. The simulation results indicate that the proposed distributed resource reservation scheme significantly improves the efficiency of resource distribution with real-time and non-real time traffic flows in WLANs, while guaranteeing the QoS for the admitted RTTFs.