Soil Seed Banks and Forest Succession Direction Reflect Soil Quality in Ziwuling Mountain, Loess Plateau, China

Abstract

The paper presents a study by taking the soil seed banks and vegetation successions of the forests in Ziwuling Mountain as indicators to analyze the effects of the ages, and the litter layers and soil depths at growing locations in seven types of forest communities on their seed bank formations and soil quality. The results showed that the seed banks at different growing locations in the communities increased in the order of upper slope, middle slope, and lower slope; the seed storages of the seed banks in the different layers of the communities varied, much more higher in the litter layers than in 0-15 cm, and the seed storages of the seed banks in the seven types of forest communities ranked in the increasing order of Pinus tabulaeformis forest, Pinus shenkaneusis forest, Quercus liaotungensis forest, Populus davidiana forest, Betula platyphylla forest, scrub communities, and grassland communities; in the meantime, the seed storage of seed banks peaked in 30-50 years old P. shenkaneusis forest, 30-40 years old P. tabulaeformis forest, 15-30 years old Q. liaotungensis, and P. davidiana and B. platyphylla forests, and 10-15 years old scrub and grassland communities, and the ages of the communities varied with the seed storages of the seed banks in a significantly correlative manner following a fitted exponential equation. In addition, the soil seed banks of the seven types of communities consisted of rich and diverse species with the herbaceous and shrub species greatly outnumbering the arbor species; in general, the coniferous forests were composed of 31 kinds of plants, the deciduous and broadleaf forests consisted of 20-29 plant species, the shrubs contained 27 plant species, and the herbaceous plants numbered 20 plant species; The various species compositions contained only 4-6 arbor species with most being foreign species. In each of the compositions, Bothriochloa ischemum was the grassland plant with the highest occurrence frequency, Sophora viciifolia and Hippophae reamnoides were the shrub plants with the highest occurrence frequencies, and Q. liaotungensis was the arbor plant with the highest occurrence frequency, and they followed by P. shenkaneusis and P. tabulaeformis. These results showed that soil seed banks and forest successions are better indicators for soil quality from natural successions.

Dynamic Parameters of Plant Communities Partially Reflect the Soil Quality Improvement in Eco‐Reclamation Area of an Opencast Coal Mine

“…The result of PCA shows that the size order of influence to R. pseudoacacia: pH > available N > available P. The soil pH can reduce the effectiveness of the trace elements and nutrient, especially the phosphorus [24,25]. Some research shows that the size order of nutrient which are absorbed by R. pseudoacacia: Ca> N > P, S. And the absorption coefficient of nitrogen is the biggest while the absorption coefficient of potassium is the smallest and the absorption coefficient can become bigger as the tree age get bigger.…”

“…For example, if the canopy density of arbor and frutex is too big, it can lead that the Larix chinensis cannot form seedlings. At last, the population will decline [23,24]. The growth of Robinia pseudoacacia and Ulmus pumila needs suitable luminous environment.…”

“…Vegetable type, the moisture and the temperature are the influencing factor to the content variation of the soil organic matter [21]. Soil temperature and activity of the edaphon increase with the drop of the elevation, and these are less favorable for the nutrient accumulation [22][23][24]. Perhaps the high temperature in low altitudes contributes to decompose the organic matter, so the organic matter content of SI and SIII is small.…”

“…With the proceeding of the vegetation recovery, soil nutrient is supplemented by the impact of the roots and the decomposition of the litters. Vegetation recovery improved the soil fertility [24,25].…”

Soil Respiration and Its Effect Factors at Different Succession Stages during the Growing Season of Larix Gmelinii Forest in Great Xing’ an Mountain

“…Recently, Chinese scientists have increased the attention paid to the succession of secondary forests [6]. While a lot of research has focused on changes in the aboveground vegetation of secondary forests [7], few studies have focused on changes to the soil it self [8], although studies have already been done on soil properties.…”