Relationship of soil fertility to biochemical properties under agricultural practices aimed at controlling land degradation

et al. 2020

Land Degrad Dev

Understanding how biotic and abiotic filters drive plant distributions is critical for informing restoration efforts of degraded lands. However, it remains unclear whether or not it is possible to develop efficient restoration strategies that are based on field investigations? Here, we conducted a field-based investigation along a land degradation gradient on the Tibetan Plateau. Along this gradient, we compared species composition, Pianka's niche overlap, and total aboveground biomass among grasses, sedges, legumes, and forbs. We also used Faith's (1992) phylogenetic diversity index (PD) and the net relatedness index (NRI) to measure community phylogenetic patterns. To understand the effects of abiotic filtering, we measured soil pH, moisture, electrical conductivity, total soil organic carbon, microbial biomass carbon, and microbial biomass nitrogen. Our results show that grasses replaced sedges and mesoxerophytes replaced mesohydrophytes with increasing land degradation. We also found that niche overlap declined with increasing degradation intensity. Furthermore, grass biomass increased, while sedges and legumes decreased, and forb biomass showed a hump-shaped relationship with degradation intensity. In addition, the communities transitioned from a clustered to a more random phylogenetic pattern. Soil conditions changed from acidic to alkaline and from fertile to harsh (p < .05). High niche overlap indicates a high biotic filtering at lightly degraded land where abiotic filtering is less stressful. However, when degradation is intense, abiotic filtering is apparent, as indicated by low levels of niche overlap. Overall, we suggest that distantly related, arid tolerant and hardy plants, and soil reclamation should be considered in degraded alpine lands restoration.

Section: Discussionmentioning

confidence: 99%

The effects of land degradation on plant community assembly: Implications for the restoration of the Tibetan Plateau

et al. 2020

Land Degrad Dev

“…Hence, it could be inferred that the incorporation of indigenous grass and sand barriers contributed to soil nutrients improvements. And the improvements of soil would accelerate the vegetation restoration [43, 44].…”

Section: Discussionmentioning

confidence: 99%

Soil and vegetation conditions changes following the different sand dune restoration measures on the Zoige Plateau

Deng

Zhang³

et al. 2019

PLoS ONE

Alpine sand dunes restoration is extremely difficult but important in the ecosystem restoration. Sand dunes are known as harsh soil and poor seed bank which freed from advantages on plants growth naturally. Effective restoration measures are required to guide the sand dune restoration. Here, indigenous grass (Elymus nutans) was sown in sand dune on the Zoige Plateau and treated with no sand barrier (CK) and environmental friendly materials including wicker sand barrier (wicker) and sandbag sand barrier (sandbag). The soil conditions were assessed by measuring the soil moisture and nutrients of the topsoil, and interspecific relationship and population niche were utilized to analyze the plant community structure variances among different restoration measures. Results showed that the soil and vegetation in the sand barriers measures were better than that in the CK. The soil moisture in the sandbag measure was 16.67% higher than that in the wicker measure. The nutrients content and microbial biomass were also the best in the sandbag measures. The ratio of strong association was the highest in the sandbag measure and the lowest in the CK, whereas the plants had the highest none association ratio in the CK. In addition, the average population niche overlap ranked by sandbag (0.39)>wicker (0.32)>CK (0.26). Thus, incorporation of sand barriers and indigenous grass seeding in alpine sand dunes could promote the sand dune restoration. And the sandbag measure showed a stronger improvement effect on the sand dune soil and vegetation conditions than the wicker measure.

“…Moreover, soil amendments may also provide indispensable assistance during the sand dunes restoration. Except for soil nutrients regulation, bioactive fertilizer amendment may also be an effective and environmentally friendly measure to promote the microbial biomass and accelerate restoration in alpine areas [43, 44].…”

Section: Discussionmentioning

confidence: 99%

Soil and vegetation conditions changes following the different sand dune restoration measures on the Zoige Plateau

Deng

Zhang³

et al. 2019

Preprint

2Restoration of alpine sand dunes has been increasingly attracting the attention of ecologists due to their 3 difficulty and importance among the mountain-river-forest-farmland-lake-grass system (referred as 4 meta-ecosystem) restoration. Alpine sand dunes are suffered from unstable soil and lack of plants. 5Efficient restoration measures are vital to guide the sand dune restoration. Whether the engineering 6 materials co-applied with seeding could achieve considerable restoration in such areas? Here, sandbag 7 and wicker as environmental friendly materials combined with Elymus nutans seeding were 8 implemented on the Zoige Plateau sand dune, comparing with the 'control' treatment that only seeding. 9We assessed the topsoil conditions by sampled the surface soil and measured the water capacity and 10 nutrients. We also utilized interspecific relationship and population niche to analyse the plant 11 community structure variances among different restoration measures. Results showed that the soil 12 conditions got clearly improved in sandbag area than that in wicker area when compared with that in 13 control area. The community in control area was the least structured, while the species showed the 14 closest related in sandbag area. In addition, average population niche overlap showed a control (0.26) 15 ﹤wicker (0.32)﹤sandbag (0.39) ranking. Thus, we suggested that sandbag or wicker co-applied with 16 indigenous grass seeding is a practical and quick restoration approach in alpine sand dunes, and the 17 sandbag may surpasses the wicker. Moreover, soil amending measures including nutrient improvement, 18and microbial fertilizer addition may further accelerate sand dune restoration. 19 Keywords: interspecific relationship; niche; Elymus nutans; sand barrier; restoration 3 20 Introduction 21The terrestrial ecosystem has experienced increasingly severe land degradation and desertification 22[1]. Desertification threatens the ecological safety and its restoration is one of the vital elements in the 23 mountain-river-forest-farmland-lake-grass system (referred as meta-ecosystem) restoration [2, 3]. The 24 long-termed complex causes (e.g., overgrazing, climate change) accelerate desertification process and 25 the sand dunes are expanding continuously on the Zoige Plateau [4-6]. Sand dunes are generally 26 covered by nutrient devoid sandy soil that lacks favourable properties for plant growth and is prone to 27 wind erosion [7]. The expanded sand dunes destroy fertile land and welfare of local populations. For 28 example, they threaten livestock productivity, society development, ecological civilization, household 29 income or human beings health [8-10]. Hence, sand dunes restoration is crucial in ensuring the 30 conservation and sustainable development of the Zoige Plateau and meeting aspiration for better living 31 standards in local people. 32Decades worth of works have been conducted on sand dunes restoration [11, 12]. Mechanical sand 33 barriers as the classical and simplest measure have been shown to contribute to re...