Indice Ref erencial Generalizado con Frases Sustantivadas Sugeridas.

Relationships among ES is critical for ecosystem-based management and is manifested as trade- offs and synergies (Yang, Ge et al. 2015). Trade-off refers to the situation that one service increase at the cost of reducing the provision of another service, while synergy refers to the situation that the sum of multiple services is enhanced than that of single services (Rodríguez-Loinaz, Alday et al. 2015). Selman provided a more detailed classification, that synergies of multiple ES in same space could be either in the same time or have a successive occurrence; moreover, besides synergy and trade-off, a third relationship is even more common that the ES may just co-exist without much influences on each other (Selman 2009).

All these relationships are inherent parts of a multifunctional urban green open space and affect the efficiency of services deliverability (De Groot, Alkemade et al. 2010). For a healthy and sustainable urban green space, to increase synergies and avoid trade-offs is a necessary part in planning practices, especially on the local and practical level. In scientific researches, synergies and trade-offs have been detected in regional scale using quantitative analyzing method, however, few analyses have been taken on smaller scales due to the dependency of large amount of relatively accurate statistics demand by the method. Thus the discussions of synergies and trade-offs in this chapter are conducted based on the results of other studies and the observation of this case.

Functions of same category normally show the same type of internal interaction. Regulating services, for instance, that all based on the natural ecosystem processes and functions, are thus in most

remarkable conditions for the well-performing of all relevant regulating services, with carbon sequestration the most outstanding one. Cultural services perform with more synergy effects (Turner, Odgaard et al. 2014). The planned routes and paths link the potential cultural services together and promote chances of synergies through the mix of targeted user groups. Among them, the educational services have contributed the most, that by offering children’s programs, all family members get the chances of aesthetic appreciation and recreation. Similarly, habitat functions are two different aspects of the same core of biodiversity, thus present as typical synergy with each other.

Provisioning services normally show mutual exclusiveness due to their dependency on land and vegetation type, however, the timber production and groundwater provision have been sustained by local managers in a paralleled and co-existence manner. The forest counts mainly for the timber production and groundwater provision in a subordinate pattern. The top priority in for the forestry office is not economic interests but the habitability of the forest and the prosperity of functions. Thus the logging work is done in a quite sustainable or low productivity approach, that about 14,000 cubic meter per year, which is less than 3 cubic meter per hectare, is cut down for wood production. Moreover, the logging work focuses on the maintenance and monitoring of the age and type of trees, that in order to keep the forest healthier and more resilient, logging locations as well as re-planting works are carefully selected based on age and type (Fig 6.1.5). In this way, the timber production generally has no conflict with the protection of this area for underground water system, as long as the logging approach keeps as it is now.

quality(Laurance, Sayer et al. 2014). Such trade-offs also happen between food production and habitat functions. However, in urban forest, this kind of trade-offs have the potential to happen but would be in a neglectable way due to the sustainable logging approach. Under the low productive logging and the simultaneous replanting, the regeneration of forest is kept in a comparatively stable level, thus the majority of regulating services would stay unaffected, with carbon sequestration a regular decrease but less influence in the long run. The fresh water provision, which refers the groundwater protection in the entire forest, has synergy effect with regulating services as well as habitat functions. Forests naturally function like a storage with huge filter to clean the water and supply for springs and rivers. Because of this protection, many potential damage on the soil and vegetation are prohibited from legal level, which provide better environment for the generating of regulating services. In addition, natural biotopes formed in the area of artificially constructed ponds, which have created new habitats for many insects, amphibians and other animal species that contribute to the genetic diversity of the area.

The relationship between cultural services and other types in regional scale diverse greatly to case context and chosen indicators (Raudsepp-Hearne, Peterson et al. 2010, Brown, Helene Hausner et al. 2015, Queiroz, Meacham et al. 2015). This type has been the evaluating difficulty in quantitative regional studies, since neither the proxies nor enquires are equally reliable as the indicators used in other ES. Moreover, cultural services are heterogeneous even in local level, which is suggested to be the most suitable scale for data collecting and analyzing(Andersson, McPhearson et al. 2015). However, based on both urban level and additional information, the cultural services have been described in a relatively sufficient way for the scale of urban forest, so as for a preliminary discussion on the interactions.

The regulating services are generally synergy with cultural services, with the exception of the certain negative effects on air pollution and greenhouse gas emission bring by the traffic of visitors. However, too much human activities post a potential influence on the habitat functions, especially how multiple routes have already been arranged in a crisscross pattern (Fig 6.1.3) that greatly go across the endangered or valuable habitats (Fig 6.1.4). Moreover, the entire Oberwald set in the critical functional area where cold and fresh air generate and help for the urban climate in city center. The result would be a domino effect if the ecosystem quality is impacted in the area.