School of Architecture/ Federal University of Minas Gerais, Brazil.
Department of Hydraulic Engineering and Water Resources/ Federal University of MinasGerais, Belo Horizonte, Brazil.
J Environ Manage. 2023 Jan 15;326(Pt A):116569. doi: 10.1016/j.jenvman.2022.116569. Epub 2022 Nov 7.
The quartzite rock outcrops and the native vegetation of grasslands located at the Serra da Calçada Mountain in Minas Gerais State (Brazil) have been severely degraded by extreme sports activities such as motocross and off-road vehicles, greatly damaging the abundant headwaters. The main consequences thereof were hilly and gully erosion processes with soil loss and the deviation of the water from its original paths. However, currently, there is no report of successful restoration efforts in severely eroded outcrops in Brazilian high-altitude grasslands (campo rupestre). Through the Universal Soil Loss Equation (USLE), we found a high general erosion rate in the study site (669.91 t·ha·year), and the specific soil loss provoked by off-road vehicles on trails was significantly greater (49 m per 100 m) than that caused by mountain bikes and trekking (5.8 m per 100 m). We performed the physical reconstruction of eroded outcrops and surface water flow paths by allocating locally available quartzite rocks. These rocks were inoculated with different species of bryophytes and planted with native species under two treatments: un-inoculated and inoculated with arbuscular mycorrhizal fungi (AMF) spores of the Rhizophagus irregularis species. After 2 years, the bryophyte communities showed a similar pattern to the preserved site, and the AMF inoculation favoured plant establishment of most species, especially of the Asteraceae, Cyperaceae, Fabaceae, Malpighiaceae, Orchidaceae and Poaceae families. The AMF also improved the soil fertility, highlighting soil P, SOM, CEC, NH-N as well as soil water content and water retention capacity. Poaceae family species showed an outstanding occupation, which was considered a functional indicator of rehabilitation success, functioning as a "hydraulic carpet" for water exportation, conduction and drainage across the outcrops. This study provides an eco-technology to restore severely eroded outcrops over headwaters using native species in the Brazilian high-altitude grasslands.
米纳斯吉拉斯州（巴西）塞拉达卡尔卡达山的石英岩露头和草原原生植被受到越野摩托车和越野车等极限运动的严重退化，对丰富的水源造成了极大破坏。其主要后果是丘陵和沟壑侵蚀过程导致水土流失，以及水流偏离其原始路径。然而，目前，巴西高海拔草原（岩生植被）严重侵蚀露头处尚未有成功恢复的报道。通过通用土壤流失方程（USLE），我们发现研究点的侵蚀速率较高（669.91 t·ha·year），越野车辆在小径上造成的特定土壤流失明显大于山地自行车和徒步旅行（100 m 内 5.8 m）。我们通过分配当地可用的石英岩来重建侵蚀露头和地表水流动路径。这些岩石接种了不同种类的苔藓植物，并在两种处理下种植了本地物种：未接种和接种丛枝菌根真菌（AMF）Rhizophagus irregularis 种的孢子。两年后，苔藓植物群落呈现出与保存点相似的模式，AMF 接种有利于大多数物种的植物定植，特别是菊科、莎草科、豆科、大戟科、兰科和禾本科。AMF 还提高了土壤肥力，突出了土壤 P、SOM、CEC、NH-N 以及土壤水分含量和持水能力。禾本科植物表现出突出的占据地位，这被认为是恢复成功的功能指标，充当了“水力地毯”，将水从露头中导出、传导和排出。本研究提供了一种生态技术，利用巴西高海拔草原的本地物种来恢复严重侵蚀的水源露头。
