16:10 〜 16:30
[HCG24-03] TREE-RING GROWTH AND NATURAL REGENERATION STATUS OF THE ULZ RIVER BASIN FOREST UNDER INCREASING ARIDITY
キーワード：Riparian forest, tree growth, natural regeneration, river basin
The world is losing nearly 100 million hectares of healthy and productive land each year. If current trends continue, 1.5 billion hectares of land will need to be restored by 2030 to achieve land degradation neutrality around the globe. Mongolia is one of the country’s most vulnerable to climate change, about three-quarters of its land is affected by desertification and land degradation. during the last 83 years, annual air temperature increased by 2.460C and precipitation decreased by 2.5%. One of the highlighted degraded ecosystems is a riparian ecosystem, therefore we have considered the Ulz River basin forest status and natural regeneration in Eastern Mongolia.
The study design focused on 3 sites selected in the upper, mid, and down parts of Ulz River. Forest research covers the nearest conifer stands that planted natural and broad-leaved species along riparian zones and shores.
In our study, with conifer stands no juvenile trees under 20 years old were recorded in either natural or cultivated forests. However, when counting seedlings aged 2-3 years within small 1×1 m plots, an average of 6-8 seedlings were recorded. This indicates that natural forest regeneration has not occurred through the dominant coniferous tree species. Instead, after wildfire damage, regeneration has been dominated by aspen. We categorized natural pine forest trees by age into three groups: young (up to 60 years old), middle-aged (60-100 years old), and old (over 100 years old). Growth analysis was conducted by examining the annual rings of tree stems.
Measurements were processed using a dedicated computer-based measurement instrument (LINTAB) and software (TSAPWIN) The growth of annual tree rings and the productivity of trees show steadily declining in chosen locations due to warming and drying. The effects of the ongoing global warming are expected to make this predicament persist. Related to Broad-leaved tree species, extreme livestock grazing intensity is the main player for broad-leaved tree species including Populus and Salix species. Through field research there are no observed trees with healthy and normal growth; Even though natural regeneration through root systems occurs, it has been entirely restricted due to extreme browsing damage of livestock grazing. The health of the forest along the riverbank has significantly deteriorated, leading to severe depletion.
It is a potential factor in changing river runoff and the ecological functions of the Ulz River.
Now is the time to protect, support, and preserve the existing natural forest resources along river shores and wetlands.
The study design focused on 3 sites selected in the upper, mid, and down parts of Ulz River. Forest research covers the nearest conifer stands that planted natural and broad-leaved species along riparian zones and shores.
In our study, with conifer stands no juvenile trees under 20 years old were recorded in either natural or cultivated forests. However, when counting seedlings aged 2-3 years within small 1×1 m plots, an average of 6-8 seedlings were recorded. This indicates that natural forest regeneration has not occurred through the dominant coniferous tree species. Instead, after wildfire damage, regeneration has been dominated by aspen. We categorized natural pine forest trees by age into three groups: young (up to 60 years old), middle-aged (60-100 years old), and old (over 100 years old). Growth analysis was conducted by examining the annual rings of tree stems.
Measurements were processed using a dedicated computer-based measurement instrument (LINTAB) and software (TSAPWIN) The growth of annual tree rings and the productivity of trees show steadily declining in chosen locations due to warming and drying. The effects of the ongoing global warming are expected to make this predicament persist. Related to Broad-leaved tree species, extreme livestock grazing intensity is the main player for broad-leaved tree species including Populus and Salix species. Through field research there are no observed trees with healthy and normal growth; Even though natural regeneration through root systems occurs, it has been entirely restricted due to extreme browsing damage of livestock grazing. The health of the forest along the riverbank has significantly deteriorated, leading to severe depletion.
It is a potential factor in changing river runoff and the ecological functions of the Ulz River.
Now is the time to protect, support, and preserve the existing natural forest resources along river shores and wetlands.