Urban forests are important as they provide recreation areas and offer ecological services. Both functions determine the status of an urban forest and reflect contradictory aspects of forest tourism development and environment conservation. However, assessment of urban forest health status at a landscape scale remains scarce. Here, we selected the Nanguo Peach Garden, China, as the study area. Urban forest health status at the landscape scale were classified into recreation and eco-conservation services. Sustainability was quantified using the principal component analysis and the Kriging method to map the landscape classification in the study area. With regard to landscape recreation sustainability, some 18.9% of the total study region was classified as “very good”. They were mainly distributed in the north, southwest, and southeast parts of the study area. The central and southeast regions, accounting for 9.5% of the total area, were classified as “very good” for eco-conservation sustainability. Regarding landscape health, the region classified as “very good” accounted for 11.1% of the total study area, and it was mainly distributed in the southern part of the area; the region classified as “very poor” accounted for 16.4% of the total area, and it was located in the northwestern and eastern parts of the study area. With improved landscape health status, the forest/non-forest patch area ratio was increased and the patch number ratio was decreased. A landscape was considered the healthiest when the forest/ non-forest area ratio was 0.65 and the patch number was 0.48. The spatial distribution of landscape recreation sustainability and eco-conservation sustainability differed in the Nanguo Peach Garden, and a close relationship was observed between the landscape health and forest landscape internal structure. Forest/non-forest patch area ratios and patch number ratios were relatively stable and constant, suggesting the urban forest landscapes were healthy. The healthiest forest landscapes were mainly distributed in the forest/non-forest transition zone and the unhealthiest forest landscape was mainly located in a single natural forest.
It is predicted that global change combined with urbanization will impact increasingly on the society and terrestrial ecosystem in the Guangdong-Hongkong-Macao Greater Bay Area of China (GBA). In this context, the cities in GBA began to plant a variety of urban trees since 2000 which are considered to play an important role in fixing carbon, improving air quality, reducing noise and providing other ecosystem services. However, data on the growth patterns and ecosystem services of the planted trees remains scarce, which hampers a comprehensive understanding of how well the planted trees adapt to the local urban environment. Therefore, we selected three widely planted tree species in Foshan, one of the core cities in GBA and investigated their tree growth and ecosystem services via a harvest campaign and soil analysis. With the same, fast tree growth as natural forests and the greatest above- and below-ground biomass among the three tree species, Ml (Mytilaria laosensis Lec.) showed a distinguished adaption to the local urban environment in terms of growth patterns, carbon fixation, stabilization against typhoon risk and water uptake capacity against potential drought risk in the future. Although Cf (Chinese fir) showed reduced diameter at breast height (DBH) and volume development, it significantly increased the total and available potassium in soils to improve the soil quality. The DBH growth of Sp (Slash pine) decreased between six and 12 years old while it recovered at the age of 12 years, probably suggesting its adaptation might take a longer time. Our results indicated that different trees had different growth patterns and ecosystem services after they were planted in cities. In a harsh urban environment under climate change, precise and comprehensive data on urban trees is necessary, helping to provide different perspectives for urban managers to select appropriate tree species and make policies.
Traditional visual quality assessments of rural landscapes rely on subjective methods. This study integrates eye-tracking technology with subjective perception evaluation to construct a visual quality assessment model for rural landscapes, aiming to reveal the intrinsic relationship between objective visual behavior and subjective perception, with the aim of providing scientific guidance for rural landscape planning to promote sustainable rural development. Using landscape photographs from nine rural sampling sites in Guangzhou, eye-tracking experiments were conducted to collect participants’ eye movement data, combined with online questionnaires to obtain scenic beauty ratings and landscape characteristic factor evaluations. The findings reveal the following: (1) Eye-tracking experiments and subjective evaluation results showed high consistency, with samples having higher scenic beauty ratings demonstrating more prominent performance in core eye movement indicators such as total fixation duration and count, and total saccade duration, and typically possessing higher landscape characteristic factor values. (2) Urban–suburban-integrated rural landscapes exhibited poorer visual quality, characteristic-preservation rural landscapes elicited more in-depth and sustained visual exploration, and clustered-improvement rural landscapes possessed higher scenic beauty ratings and landscape characteristic factor values. (3) Total saccade duration was the key eye movement indicator for predicting scenic beauty ratings. (4) Multiple landscape characteristic factors significantly influence eye movement behavior.
Assessing the landscape health of suburban forest parks is a prerequisite for achieving the dual objectives of forest resource conservation and recreational services. However, studies that analyze landscape health in suburban forest parks at a landscape scale by subdividing the landscape into multiple sampling units and adopting a multi-functional perspective have been limited. This study focuses on Xiqiao Mountain National Forest Park and establishes a landscape classification system and indices, taking into account its multifunctionalities. The study employs the entropy weight method to determine indicator weights and utilizes grid analysis and spatial interpolation to analyze the spatial distribution of landscape health under multiple sampling units and functionalities, along with the differences in its impact and influencing factors. The results indicate that: (1) regions with “very poor” and “poor” landscape health grades under multiple sampling units and functionalities exhibited a sheet-like distribution pattern, covering approximately 69.46% to 98.86% of the total area. In contrast, regions with “very good” and “good” grades are primarily located in block-like or linear patterns in the northern, central, and southern regions of the park, accounting for approximately 1.07% to 17.20% of the total area. (2) The area ratios of “very good” and “good” landscape health grades for recreational landscapes under varying sampling units were consistently higher than those of the same grades for eco-conservational landscapes, with a 5.03%–15.43% difference. This suggests a greater emphasis on recreational functionality. (3) The impact of three different sampling unit sizes on the landscape health of Xiqiao Mountain National Forest Park under multifunctionalities is not significantly different; however, the forest/non-forest area ratio and quantity ratio are vital factors influencing its landscape health. The landscape health assessment results, considering multiple sampling units and functionalities in this study, serve to provide technical method support and practical case references for the planning, construction, and management decision-making of suburban forest parks.
30 August 2021 in Frontiers in Bioscience-Landmark
Background: urban forest in coastal cities encounters multiple disturbances of frequent typhoon events caused by global change, under which ecological remediation can help to improve urban environment. We measured and analyzed the growth and ecosystem services of four newly-planted tree species in Zhuhai after Typhoon Hato (2017), aiming to evaluate the efficiency of the ecological remediation. Methods: National Meteorological Information Center of China supplied climate variables. From June 2018 to December 2019, we measured soil physical and chemical properties, above- and below-ground development regarding stem, tree height, and root growth of all the selected tree species. Results: Sl (Sterculia lanceolata Cav.), Ir (Ilex rotunda Thunb), Ss (Schima superba Gardn. et Champ.) could be more wind-resistant from the above-ground morphological perspective. For the below-ground process, Sl was the only tree species with continuous development, while Ir, Ss, and Es (Elaeocarpus sylvestris (Lour.) Poir.) decreased. Furthermore, Sl, Ir, and Ss maintained their investment in deep roots when Es had apparent deep root biomass reduction. The edaphic condition showed notable improvement in chemical properties rather than physical properties, especially for AN (available nitrogen), AK (available potassium), and SOM (soil organic matter). Conclusions: The ecological remediation in Zhuhai after Typhoon Hato (2017) was efficient, and in the future, tree species like Sl with advantages in root development and morphological profile were preferentially recommender for plantation in typhoon-affected areas.
Landscape health assessments are crucial for balancing conservation and use practices. However, studies considering different land use intensities and grid scales from a functional perspective are limited. This study aimed to develop a landscape classification and indicator system based on functional characteristics using Xiqiao Mountain National Forest Park and Yunyong National Forest Park as research objects. The entropy weight method was used to determine indicator weights, and grid analysis and spatial interpolation were used to analyze the spatial distribution, impact differences, and factors influencing landscape health. The effect of different grid scales on landscape health under varying land use intensities first weakened and then strengthened with increasing grid scales; the optimal grid scales for the two parks were 54 × 54 m and 66 × 66 m, respectively. The forest/non-forest area ratio decreased as the health level of the landscape increased. At the optimal grid scale, the threshold range of the forest/non-forest area ratio for achieving optimal landscape health was 4.46–5.81 and 0.79–0.87 in the two parks, respectively. The results indicate that improved landscape health in suburban forest parks requires the intensive development of construction land, enhanced forest management, and functional synergistic designs to promote coordinated functional development.