<p>Urban forest ecosystems are the key contributors to the green spaces within metropolitan landscapes, offering numerous ecological services. But the combined effects of anthropogenic activities driven by population growth and escalating resource demands have precipitated rapid modification in forest structure, extent, and environmental conditions (i.e., nutrient dynamics) of such areas. This study investigates how human disturbances affect Korean pine urban forests through examinations of non-spatial structure and physiological, biochemical and soil responses. Tree height decreased (<i>R</i><sup><i>2</i></sup> = 0.463, <i>p</i> &lt; 0.001) while canopy cover increased (<i>R</i><sup><i>2</i></sup> = 0.132, <i>p</i> &lt; 0.001) as disturbance intensity intensified. Needle indole-3-acetic acid (IAA) and gibberellic acid (GA<sub>3</sub>) content varied significantly (<i>p</i> = 0.017 and <i>p</i> = 0.049) across the various disturbance levels, with significant seasonal cytokinin and GA<sub>3</sub> changes under very low disturbance (<i>p</i> = 0.023 and 0.040) and pronounced IAA and GA<sub>3</sub> under heavy disturbance (<i>p</i> = 0.026 and 0.024). Needle moisture content varies significantly (<i>p</i> = 0.029) with increasing disturbance and significant seasonal changes only when disturbances reached heavy intensity level (<i>p</i> = 0.0138), and chlorophyll (Chl) a (<i>p</i> = 0.0002), Chl b (<i>p</i> = 0.009), and total Chl (<i>p</i> = 0.0004) were disturbance sensitive. In addition, annual glucose (<i>p</i> &lt; 0.001), starch (<i>p</i> &lt; 0.01), and non-structural carbohydrate (<i>p</i> &lt; 0.001) content in needle, branches, and root were exhibited significant change with increasing disturbance, seasonal variations especially found in heavily disturbed sites (<i>p</i> &lt; 0.05). Nutrient element content (i.e., carbon and nitrogen ratio, total phosphorus, and total potassium) in needles, branches, roots, and soil showed significant differences (<i>p</i> &lt; 0.05) with increasing disturbance intensities, except for phosphorus in roots which was not significant. These findings quantified the threshold at which urban disturbances impair Korean pine resilience and point out the urgency of regulating anthropogenic disturbances and restoring soil nutrient conditions. This study advances urban forest ecology by linking disturbance intensity to physiological thresholds and nutrient depletion, supporting for integrated conservation frameworks that prioritize urban forests alongside protected areas. Future research should target urban Korean pine growth, particularly regarding height increments, and highlights the importance of nutrient management and disturbance mitigation.</p> Graphical abstract <p></p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Impact of anthropogenic disturbance on tree non-spatial structure, seasonal physiology and nutrient dynamics in urban forests of Pinus koraiensis

  • Sudipta Saha,
  • Tika Ram Poudel,
  • Ruxiao Wei,
  • Lei Huang,
  • Nathan James Roberts,
  • Haibo Wu,
  • Mingshan Jiang,
  • Donghui Han,
  • Peng Zhang,
  • Hailong Shen

摘要

Urban forest ecosystems are the key contributors to the green spaces within metropolitan landscapes, offering numerous ecological services. But the combined effects of anthropogenic activities driven by population growth and escalating resource demands have precipitated rapid modification in forest structure, extent, and environmental conditions (i.e., nutrient dynamics) of such areas. This study investigates how human disturbances affect Korean pine urban forests through examinations of non-spatial structure and physiological, biochemical and soil responses. Tree height decreased (R2 = 0.463, p < 0.001) while canopy cover increased (R2 = 0.132, p < 0.001) as disturbance intensity intensified. Needle indole-3-acetic acid (IAA) and gibberellic acid (GA3) content varied significantly (p = 0.017 and p = 0.049) across the various disturbance levels, with significant seasonal cytokinin and GA3 changes under very low disturbance (p = 0.023 and 0.040) and pronounced IAA and GA3 under heavy disturbance (p = 0.026 and 0.024). Needle moisture content varies significantly (p = 0.029) with increasing disturbance and significant seasonal changes only when disturbances reached heavy intensity level (p = 0.0138), and chlorophyll (Chl) a (p = 0.0002), Chl b (p = 0.009), and total Chl (p = 0.0004) were disturbance sensitive. In addition, annual glucose (p < 0.001), starch (p < 0.01), and non-structural carbohydrate (p < 0.001) content in needle, branches, and root were exhibited significant change with increasing disturbance, seasonal variations especially found in heavily disturbed sites (p < 0.05). Nutrient element content (i.e., carbon and nitrogen ratio, total phosphorus, and total potassium) in needles, branches, roots, and soil showed significant differences (p < 0.05) with increasing disturbance intensities, except for phosphorus in roots which was not significant. These findings quantified the threshold at which urban disturbances impair Korean pine resilience and point out the urgency of regulating anthropogenic disturbances and restoring soil nutrient conditions. This study advances urban forest ecology by linking disturbance intensity to physiological thresholds and nutrient depletion, supporting for integrated conservation frameworks that prioritize urban forests alongside protected areas. Future research should target urban Korean pine growth, particularly regarding height increments, and highlights the importance of nutrient management and disturbance mitigation.

Graphical abstract