The Role and Practice of Geodiversity in Serving Ecosystems in China

Abstract

This paper demonstrates how geodiversity interconnects with the particular ecosystems and practices within China. As an essential component of natural diversity, geodiversity can provide the necessary services and products to ecosystems and humans. In current Chinese research, theories and methods of geodiversity in China are relatively lacking. We use the Millennium Ecosystem Assessment classification as a basis for four categories: provisioning, regulating, supporting, and cultural services. In so doing we present the products and services associated with geodiversity in China. In practice, we found that China, especially in light of its geological survey, already has a working basis for maintaining and enhancing the quality of its geodiversity and geosystem. To better advance the theory and practice of geodiversity in China, we suggest making geodiversity and biodiversity the object of geological surveys to understand its natural processes and distribution. This will ensure that nature as a whole can be appropriately managed and protected, that geodiversity indicators in ecosystem assessments can be clarified, and that equally essential elements of nature policy to promote geodiversity and biodiversity can be added.

1. Introduction

Geodiversity is the abiotic diversity of materials, forms, and processes on the Earth’s surface and subsurface [1,2]. Geodiversity is the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (landforms, processes) and soil features [3]. Alongside the diversity of geological structures and processes there are materials such as rocks, soils, and water; landforms such as mountains, glaciers, and lakes; and processes such as soil formation, coastal erosion, and sediment transport [4,5]. In terms of natural variability, geodiversity includes the movement from a purely static feature at one extreme to a collection of elements at the other, i.e., their formation processes [6].

Ecosystems and geodiversity are inextricably related. Geodiversity provides and supports many essential ecosystem goods and services, such as the provision of energy and supply services that include minerals and water resources. Similarly, it often influences ecosystem stability through the processes of interaction between materials, forms, and processes such as rocks, landforms, soils, hydrology, and other diversities within nature. For example, Hu et al. (2020) [7] used the example of the Galongla Mountain in Medog County, in the Tibetan Plateau, to show that geological processes are vital to ecosystem properties. An example of this is provided by the chalk aquifers in Ordos Basin significantly control the important mineral composition and soluble salt content of water-bearing rocks and their spatial distribution, as well as the spatial distribution of aquifers and compartments, and significantly influence the regional distribution changes of alternating conditions of deep groundwater circulation, which have different effects on ecosystems [8]. This mineral endowment is an organic part of the geodiversity in a region. Geochemical anomalies are phenomena of exceptionally high (enriched) or low (depleted) elements relative to background and are special patterns of regional geochemical distribution of elemental allotropes [9]. These include the variation in element background values in different types of rocks, the anomalous geochemical background values in some mineral resource-rich areas, the correlation between Sn deposits and Sn geochemical anomalies in southwest China [10], and demonstrate a close connection with the ecosystem service function of a region. Maintaining healthy and stable natural ecosystems and preventing and mitigating ecosystem degradation requires the conservation and management of biodiversity and geodiversity. Humboldt’s “unity of nature” [11,12,13,14], a sustainability theory, underlies how geodiversity affects ecosystem service provision. More scholars now recognize that geodiversity is an essential root of ecosystem conservation for sustainable development [12,15,16,17]. Many aspects of sustainable development are based on the geological context and access to subsurface mined material, but very limited efforts have been devoted to developing measures to support SDGs [14] and essential geodiversity variables have not been integrated into the SDGs.

In 2000, Decision V/6 of the CBD stated that “…a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way.” [18]. The AHC (2002) [19] sets out key principles for nature conservation in national contexts and states that conservation is based on respect for biodiversity and geodiversity, while the IUCN (2008; 2020) [20,21] published Conservation and management of geodiversity in protected and conserved areas. Geodiversity determines ecosystem services and, in particular, determines the specificity and functional differences of ecosystems at the national level. Some countries develop policies for the conservation and exploitation of high geodiversity. Geodiversity Action Plans (GAPs), are used widely within the United Kingdom to inform and record action for geodiversity [22]. The USA’s National Park Service and National Natural Landmarks Program and Canada’s National Parks network implement integrated geodiversity and biodiversity management [23]. In 2019, the Guidance Opinions on Establishing a Nature Reserve System with National Parks as the Mainstay, issued by the Chinese State Council, stated that the purpose of establishing nature reserves is to protect biodiversity and geodiversity at the same time.

The discussion on understanding the value of geodiversity in China is currently focused on geoconservation research [24,25,26,27]. Less study has been undertaken regarding the integration of geodiversity with ecosystems and natural resources decision management as a research focus in China.

Determining the geological contribution to ecosystems can be demonstrated through the ecosystem pathway, where there is a need to strengthen geological surveying, monitoring, and evaluation to contribute to the understanding of natural processes and distribution for the proper management and conservation of nature as a whole. Geology is the bedrock to the sustainable management of natural resources [28] and The geological survey organizations (GSOs) are scientific research organizations established to provide public geoscientific services for society. Currently, natural resource management is becoming increasingly important as countries implement the principles of sustainable development. National GSO agencies are active in providing essential Earth Sciences information on Earth systems, natural hazards, and climate change [29], this is similar to geodiversity, which is increasingly recognized as an important component of the Earth Sciences. We live in a dynamic environment where knowledge of the river, coastal, and slope processes is an essential component of nature-based solutions to manage hazards such as flooding, sea-level rise, coastal erosion, and landslides. Geological surveys have the advantage of developing geodiversity theory, improving geodiversity data analysis, and organizing several national and international authorities’ geodiversity charters or programs.

In 2007, the British Geological Survey (BGS) participated in the Northumberland National Park: Geodiversity Survey and Action Plan. While in 2010, the BGS participated in the U.K. Geodiversity Action Plan, which proposed strengthening the conservation and management of geodiversity in environmental planning and development policy and legislation. The BGS’s role was to map, investigate and provide information on the U.K.’s geodiversity. The BGS was involved in the drafting and implementation of the Geodiversity Charter for Scotland, Northern Ireland, and England. In 2016, the USGS conducted a climate change vulnerability survey of 19 ecosystems in the southeastern United States, which considered the relationship between geodiversity and biodiversity. The USGS also undertakes global ecosystem classification and mapping commissioned by the Group on Earth Observations, which considers geodiversity elements in ecological land classification units. The USGS participates in surveys and mapping geodiversity atlases to help integrate geodiversity and biodiversity management within U.S. national parks. In 2017, the Australian Department of Environment and Energy, with Geoscience Australia’s participation, launched a five-year Geological and Biological Area Assessment Program.

This paper analyzes the development process of geodiversity research and applied practices in various countries. Based on the Millennium Ecosystem Assessment (MA) (2005) classification, we describe the services geodiversity provides to China’s ecosystems, and the work and cases that China has undertaken regarding geodiversity. Finally, it concludes with a discussion and a summary.

2. China’s Geodiversity Contribution to Ecosystem Services

The continent of China has undergone long and complex tectonic evolution from the Archean to Cenozoic eras to arrive at an abundant tectonic setting where the Paleo-Asian Ocean, Tethyan, and Western Pacific domains meet in a triangular framework [30] in the east, there are Qinling–Tongbai–Hong’an–Dabie–Sulu in the central, the eastern Altaids orogenic belt in the north, and the Songliao, Bohai Bay, South Sea oil- and gas-bearing basins. In the west, there are the Himalaya, Kunlun, Altyn Tagh, Qilian, Tianshan and the western Altaids orogenic belt, as well as the Tarim, Qaidam, and Junggar oil- and gas-bearing basins [31]. The Qinghai-Tibet Plateau is a unique ecological environment on the earth with steep mountains and rivers and rich natural resources, known as the China Water Tower [32]. With different geological formations, climates, landforms, topography, and ecosystem characteristics from the humid and semi-humid regions in the east, the arid and semi-arid regions in the northwest, to the Tibetan Plateau region [33], China has world-class geodiversity that provides for the well-being of humans and natural ecosystems. China has a relatively stable landmass that existed before the Aurignacian [34]. We live in a dynamic and changing environment and already see the impacts of climate change on humans, such as at the Qinghai-Tibet Plateau, which is the ecological and climatic source of climate stability in China. To manage and adapt to climate change impacts, we need to understand natural processes, including the interactions between geodiversity and more general ecosystems.

The MEA system classifies services into four groups: regulating services, which are ways in which natural processes regulate the environment; supporting services, which are processes that support the natural environment; provisioning services, which are raw materials used by society; and cultural services, which are non-tangible benefits of the natural environment that benefit the community in a spiritual or cultural sense. We use the MEA classification as a basis for presenting the products and services associated with geodiversity. The four broad categories of products and services that geosystems provide to organisms and humans are considered to be of significant benefit to society primarily as geosystem services, all of which are based on the fact that the Earth is a geological system [3,28] [

Table 1. Examples of services and productions by geological processes based on Gray (2013) [3] and Brilha et al. (2018) [35]. These services and productions are classified according to the MEA and are indicated by geological role or the result of geological processes.

Geosystem Services	Geological Processes
Provisioning	Freshwater
	Provides essential inorganic nutrients for food, fiber, biochemicals, natural herbs and medicines
	Renewable and non-renewable energy sources
	Non-metallic minerals
	Metallic minerals
	Gem-jade minerals
Regulation	Air quality regulation
	Climate regulation
	Water resource regulation
	Regulation of soil erosion
	Regulation of natural disasters
	Rock cycle
	Water cycle
	Regulation of the water quality due to the circulation through rocks and sediments
	Carbon and other biogeochemical cycles
	Carbon sequestration
Cultural	Spiritual and religious values
	Aesthetic value
	Geotourism and leisure
	Geological Heritage
	Earth Science Knowledge
	Education and training
	Environment monitoring and forecasting
Supporting	Soil processes
	Nutrient cycle
	Habitat provision
	Establishing ecological corridors
	Platform for infrastructures (roads, dams, production of renewable energy)and urban development
	Burial and storage (municipal landfill, radioactive waste storage, cemeteries)

].

2.1. Provisioning Services

The main contribution of geodiversity to ecosystem provisioning services is through freshwater, mineral resources, construction materials, and renewable energy [36]. The benefits are mainly provided to biological resources through nutrients and soils. Both active and abandoned mines play an essential role in enhancing geodiversity and biodiversity [14,37]. China is rich in water resources and ranks sixth in the world in terms of volume, but China’s freshwater resources are tight because of its large population [38]. Mineral resources are essential to sustain modern economies and lifestyles. By the end of 2018, 173 minerals have been discovered in China, including 13 energy minerals, 59 metal minerals, 95 non-metal minerals, and 6 groundwater and gas minerals. China’s gem-jade resources are widely distributed and diverse, with 184 types of gem-jade discovered (not including ornamental stones and inkstones) [39]. Both active and abandoned mines play an essential role in enhancing geodiversity and biodiversity. Geodiversity, biodiversity, and recreational pastimes can be maximized through the precise planning of operation periods and restoration sites. From 2001 to 2018, the total restoration and treatment area of mines nationwide was about 1,004,600 hectares. The production of agricultural nitrogen, phosphorus, and potassium fertilizers was 57,311,700 tons, crucial to China’s agricultural sector. In 2019, hydro power, nuclear power, wind power, and solar power accounted for 27.7% of all electricity generation, and the proportion is increasing.

2.2. Regulating Services

Geodiversity regulates the primary conditions for life and modern society’s existence, providing benefits or harms to human and animal health through the composition of rocks, soil, and water and their effects on soil, water, and air quality. China’s lithospheric carbon pool is the largest globally, and elemental carbon is a significant component of carbonate rocks and sedimentary rocks in the lithosphere [40]. Its release to the atmosphere is regulated by sedimentation and volcanism. Rock weathering participates in the global carbon cycle on both shorter and longer time scales, especially for carbonate rocks, which have an important influence on the atmospheric CO₂ cycle on short time scales. Qiu Dongsheng et al. (2004) [41] estimated the carbon sink capacity due to rock weathering in China to be about 1.41 × 10⁷ tons of carbon. The hydrological cycle is observed from renewable resources, where both groundwater and surface water originate from atmospheric precipitation and are transformed into each other [42]. Take the endorheic basins in Xinjiang and Gansu for example, where the minimal amount of precipitation at the bottom of the basin is almost completely evaporated, and no adequate freshwater resources are formed. The local freshwater resources mainly come from precipitation and snowmelt in the mountainous areas around the basin which infiltrate into the pre-mountain floodplain fans composed of gravels and coarse sands, which are then converted into groundwater. The floodplain fan’s debris material gradually becomes more delicate from upstream to downstream, and the ability to transmit groundwater gradually decreases. Finally, the groundwater is blocked at the edge of the floodplain fan and then overflows to the surface in spring water, which is converted into surface water again. The geology, topography, soils, and hydrological pathways of the catchment are essential for water regulation. The geomorphic and sedimentary characteristics of rivers fundamentally affect water quality and habitat availability. Still, the contribution of river geomorphology to human well-being is often overlooked in mainstream classifications of ecosystem services. China has abundant river resources, with more than 1500 rivers with watershed areas of 1000 km² or more, giving various ecosystem regulating functions [43]. Geodiversity contributes to the regulation of erosion and natural hazards through coastal protection, soil erosion, landslide control and flood control [44]. Rivers can serve as a regulating function for hazards by preventing floods, droughts, sedimentation, and erosion. Often, management time frames are based on human experience and do not take full advantage of earth science evidence [45]. Sustainable solutions include collaborative work with natural processes and rely on the practical application of geoscientific knowledge as part of a more integrated, process-based approach that includes maintaining sediment transport or natural flow regimes and diffuse beach reconnection in rivers.

2.3. Supporting Services

The main contributions of geodiversity to ecosystem supporting services are habitat creation and maintenance, soil formation, biogeochemical cycling, and water cycling (Gordon & Barron 2013 [36]). However, current traditional approaches to conservation management focus on species and protected areas, often ignoring the broader ecosystem functions and linkages. Policies should integrate geomorphic processes and soil and bedrock properties and conditions to maintain dynamic habitats, sustain and enhance ecosystem stability, and protect landscapes [46]. Geodiversity strongly influences the spatial distribution and diversity of a range of habitats and species. For example, with water storage and the operation of reservoirs and the consequent inundation of the reservoir basin, sedimentation, and downstream scouring of the reservoir there are potential river and lake connectivity changes which result in changes to local habitat characteristics. Dong et al. (2007) [47] counted more than 5400 sluices in the Huaihe River basin in China and found that sluices and dams disrupt connectivity and kill large numbers of fish and shrimp in waters such as Hongze Lake. Another essential supporting service for geodiversity is soil formation. Conditions of soil formation such as moisture, rocks, and other parent materials significantly affect soil organic matter content. The organic matter content of Chinese soils is not high, ranging from 2.14 to 10 kg/m² [48]. Many forest soils are distributed in northeastern China and on the edge of the Tibetan Plateau. The northeastern and southeastern parts of the Qinghai-Tibet Plateau have alpine soils with high organic matter content and support many habitats and forests of national and international importance. The western desert and semi-desert areas have low soil organic matter input and severe soil erosion. The Zoige Plateau is one of China’s critical bog distribution areas, accounting for 4.1% of the total bog area in China, and is a vital plateau bog soil and peat soil distribution area in China [49]. The phenomenon of increasingly extensive urban geological survey work in China indirectly reflects the idea that geodiversity is a platform for promoting urbanization to build infrastructure and urban development. Since 2010, comprehensive urban geological surveys have been carried out in the Beijing-Tianjin-Hebei region, Yangtze River Delta, Pearl River Delta, and other large urban clusters and have contributed to completing the preparation of 1:250,000 basic geological environment maps [50].

2.4. Cultural Services

The main contributions of geodiversity to the cultural services of ecosystems are non-tangible benefits, which include spiritual and religious values, aesthetic value, geotourism and leisure, geological heritage, earth science knowledge, education and training, environment monitoring and forecasting, all of which contribute to the development of cultural activities. Geodiversity plays a vital role in the knowledge services of ecosystems. For example, the distribution area of exposed karst in China is 120 × 10⁴ km² [51]. There are many types of karst landforms, especially the needles and peaks landscape, within different poses and expressions, especially in Guangxi Guizhou and eastern Yunnan. Through the survey and evaluation of karst geological sites and caves, we can find karst landscapes and bring people the enjoyment of ecotourism. At present, the total number of exploited touring caves in China is about 400, receiving nearly 40 million visitors per year and a direct income of billions of RMB. In China, geoparks are a tool for geological heritage protection and a base for geological scientific research and popularization. By the end of 2019, China had approved 220 national geoparks and more than 300 provincial geoparks. Since 2004, 39 world geoparks have been approved by UNESCO [52].

In addition, topography, sediments, and paleoecology document past changes in ecosystem services and landscape adjustments over time. Wang and Jian (1990) [53] have shown that, as politicians need to learn from history, so scientists need to learn analogies and discover patterns from paleoclimate and the paleoenvironment when predicting changes in the environment human societies live in. Paleoenvironmental perspectives can also play a key role in supporting conservation biology while understanding ecological and evolutionary processes can better inform the restoration of sustainable primary woodlands. Zhong et al. (2020) [54] have studied the paleoecology and paleoenvironment of the Hongshan bed through fossils in Zhangye National Geopark. Understanding the extent of past natural variability or boundaries of variability is particularly important for predicting and planning change, validating conservation management decisions and ecological restoration, and helping to prioritize management interventions with constrained resources. For example, Sun et al. (2018) [55] have developed wetland restoration goals by tracing the ecological characteristics of wetlands during historical periods when they were not affected by human activities, or affected by them less, which could restore them to a healthier state.

2.5. Practice of Applying Geodiversity to Ecosystem Pathways in China

First, China’s nature reserve system, mainly national parks, has started to protect geodiversity. In 2019 the Guidance on the Establishment of Nature Reserve System with National Parks as the Mainstay, issued by the State Council government, pointed out that the purpose of establishing nature reserves is to protect biodiversity and geological and geomorphological landscape diversity. Second, geological survey work supports the protection of ecosystems with good groundwork. China has completed 1:200,000, 1:250,000, and 1:50,000 scale regional geological surveys, environmental geological surveys, and hydrogeological surveys covering the whole country or some areas. Furthermore, China has carried out two soil censuses, nine forest resource surveys, two grassland resource surveys, two wetland resource surveys, two detailed land use surveys, one national geographic survey, and multi-scale physical geography, agricultural, geological and landscape surveys [56]. Chinese geological survey institutions launched a new round of national forest resources field surveys in 2020 [57]. Third, surveys serving the ecosystem are also carried out in an orderly manner. For example, the 1:50,000 ecological geological survey was carried out in the Daba Mountains area in 1994, and the “1:250,000 Tieling ecological geological survey” was implemented in 2003, through which it was found that soil chemical elements are the primary source of biological nutrition [58]. The element types and content levels are controlled by the mineral composition of the parent rock. Fourth, Chinese geological survey institutions also carry out thematic surveys. For example, to carry out peatland surveys the China Geological Survey completed a survey of peat bog carbon pools in Yunnan Province and carried out surveys of 21 peat patches in forest bogs and adjacent sandy grasslands in the Daxinganling Mountains, which are in northern China and belong to a specific area of cold-temperate bog wetlands, and initially summarized the working methods of peat bog carbon pool surveys and considerations for calculating peat resources reserves. Geological survey institutions serve ecological restoration in karst areas [59]. One third of China’s land area is karst areas. Karst areas are highly prone to induce major environmental problems such as stone desertification, karst drought, seawater intrusion, groundwater pollution, and geological disasters such as karst collapse and depression inundation. The China Geological Survey has implemented more than 120 stone desertification ecological restoration projects in southwest stone desertification areas since 2001 as well as surveys evaluating more than 600 karst geological sites and more than 3000 karst caves with development value.

3. Results

We use the Millennium Ecosystem Assessment classification as a basis for demonstrating the reliance on geodiversity, the four broad categories of goods and services that geological systems provide to organisms and people. We try to summarize the practice of geodiversity service ecosystems from the perspective of geological surveys and find that China, especially in the geological survey, already has a working basis for maintaining and enhancing the quality of geodiversity and geosystem. As a policy driving natural resource management in China, ecosystem management now provides a framework for the better integration of biodiversity and geodiversity through its contribution and function in providing ecosystem services. China’s geodiversity provisions services to its ecosystem, the main contribution of which is through freshwater, mineral resources, construction materials, and renewable energy. The regulating services provided by geodiversity to the ecosystem, providing the primary conditions for life and modern society, are delivered through the composition of rocks, soil, and water in China. Geodiversity to ecosystem supporting services strongly influence the spatial distribution and diversity of a range of habitats and species in China. It also plays a vital role in the knowledge services of ecosystems in China, services which include geotourism, geological heritage, earth science knowledge, geological education and training, all of which contribute to the development of cultural activities. The study of geodiversity and biodiversity would benefit from closer collaboration to survey biological, rock, hydrological, and soil data. Geodiversity data management strategies will be an essential part of the future conservation of biodiversity and ecosystems.

4. Discussion and Conclusions

4.1. Discussion

Geodiversity is the nexus of China’s geological survey work to maintain a stable and sustainable ecosystem, one which expands the service field of geological work through its research and practice. In China, geological surveys have undertaken the task of providing basic geological information and data for society so that the China Geological Survey can produce and provide basic national geological information and other public welfare products, with provincial and municipal geological exploration organizations being responsible for the survey of basic geological information in the region. As China moves toward ecological civilization, the input of geological survey data has changed from a past focus on mineral exploration to a general pattern of coordinated development of geological survey work in minerals, water, soil, forest, grassland, surface environment, and geological disasters. In 2020, the total input into groundwater surveys, surface environment surveys, and geological disaster surveys in China was 3.451 billion yuan, and the ratio of the input to the total input of national geological surveys increased from 5.3% in 2012 to 21.4% in 2020 [60]. The China Geological Survey accelerates the comprehensive geological survey of natural resources in Hainan, Fujian, Chengde, and other demonstration areas to construct an ecological civilization and expand the survey fields of forestry and grass, land, and ecology. A comprehensive survey of natural resources provides essential support for the management of ecosystem health and stability through the survey, evaluation, and monitoring of geodiversity, and the mapping of the quantity and quality of natural resources, from underground to deep processes and surface processes that are closely related to the survival of life.

Geodiversity can provide geological solutions for ecosystem conservation and restoration in China. Geodiversity supports ecosystem formation and maintenance and provides a “natural stage” for biodiversity. Natural ecosystem conservation and restoration is the management of biodiversity and the management and protection of geodiversity cannot be ignored. The problem of ecosystem quality and function in China is outstanding and the overall Chinese grassland ecosystem is still fragile. The ecological function of some rivers, wetlands, and lakes has been reduced or lost, with the national sandy land area at 172 million hectares and the soil erosion area at 274 million hectares [61]. China’s geological survey work has expanded into forestry, land, and ecological surveys. Geological work can recognize ecological processes, evolutionary processes, and earth processes through geodiversity research and investigation and propose geological schemes that follow the laws of natural ecosystem succession.

4.2. Conclusions

The fact that the concept of ecosystem services had not previously included geology has undermined valid results. It has ignored the scientific knowledge that demonstrates the close correlation between natural biotic and abiotic processes. Geodiversity is intrinsically important as a rare or representative component of natural diversity. Although current research on geodiversity in China is relatively focused on geological conservation, it is clear from the practices we have compiled that China, like other internationally geological survey institutions, already has a good working base for maintaining and enhancing ecosystem quality and has begun research on specific ecological issues. Geodiversity is usually closely related to biodiversity and it is crucial to consider both geodiversity and biodiversity as objects for conducting geological surveys, as this will lead us to better understand natural processes and distribution. Thus, nature as a whole can be appropriately managed and protected. As Schrodt et al. (2019) [14] have advocated, it is important to recognize and integrate geodiversity into ecosystems as the most effective means to advance sustainable nature resources stewardship.