To maximize the ecological services of urban forests, a better understanding of the effects of urbanization on urban forest characteristics, landscape metrics, and their associations is needed for landscape-related regulations in space-limited green infrastructure of metropolitan regions. In this study, Harbin, a typical fast-growing provincial-capital city in Northeast China, is used as a case study. Based on remote sensing images, field surveys, and correlation and variation partitioning analyses, we conclude that landscape characteristics and forest attributes have large variations among different urbanization intensity (UI) regions. Forest patch density (PD), landscape shape index, woody plants species richness, and the Shannon–Wiener index (H′) increased linearly, while stem section area and tree height decreased linearly with the increasing of UIs. UI had a greater influence on tree size and forest community attributes than the forest landscape pattern. Accordingly, any landscape regulation on forest attributes should be implemented according to UIs. In addition, Euclidean nearest neighbor distance(ENN-MN), mean perimeter-area ratio (PARA-MN), fractal dimension index(FRAC-MN), and PD could probably indicate forest attributes the most, e.g., the increase of PARA-MN may be accompanied with taller trees in low and heavy UI regions, but lower woody plants species evenness in low and medium UI regions. More diversified woody plants species, and afforested areas should be advocated in a low UI region, while in a heavy UI region, the conservation of large trees should be implemented. Our results highlight that the implementation of urban forest management should vary according to different urbanization regions to maximize ecological services.
The new reality of networked publics on social media calls for crisis communication practitioners and researchers to understand the narratives generated by publics on social media during organizational crises. As social media publics possess diverse, unique characteristics and communicative needs during a crisis, they form interpretative communities and co-create various symbolic interpretations of the crisis. Extending the public-centric and narrative perspective to the context of social media crises, we examined what crisis narratives were constructed by social media publics (i.e., multiplicity) and how these narratives changed by crisis stages (i.e., dynamics). Using topic modelling based on large-scale Twitter data of the Chipotle E. coli crisis (N?=?40,610), we identified ten narratives subsumed under two themes (i.e., sharing-based and conversation-based) based on publics’ social constructions of their perceived risks and crisis experience. On the one hand, sharing-based narratives, heavily impacted by publics’ shared media coverage, reflected media crisis narratives and salient risk perceptions aligning with the news agenda. On the other hand, conversation-based narratives, fueled by publics’ opinion expression and emotional venting, demonstrated publics’ interpretations of their experience with the organization in the crisis with less salient but more diversified risk perceptions. Crisis managers are recommended to produce and deliver compelling narratives resonating with different groups of social media publics during crises. 相似文献