The reintroduction of rare and endangered species is one of the most important approaches to conservation and ecosystem restoration, but it has still proven to be an adventurous undertaking and most reintroduction programmes fail, so successful demonstrations are needed. Père David’s deer (Elaphurus davidianus, Milu in Chinese) could be considered one of conservation’s great success stories, as this species’ path on the road to extinction has been reversed by a combination of ex-situ conservation and successful re-introduction in China. The species had been consigned to an imperial hunting ground when the last Chinese herds were exterminated during the fall of the Qing Dynasty (1644-1912). Fortunately, a few of the last remaining individuals were sent to European zoos. From these animals, a herd was bred on the 14^th Duke of Bedford’s estate, Woburn Abbey, and between 1985 and 1987, and 38 Milu were donated back to China for re-introduction in Beijing Milu Park (BMP), the former imperial hunting ground. An additional 39 deer were released at Dafeng National Nature Reserve (DFNNR), Jiangsu Province in 1986. In both of these safe and protected locations, the Milu thrived allowing for over 700 Milu to be sent to a further 82 sites throughout the species’ original Chinese range over the last 36 years. As a result, the Milu population totaled 9136 by 2021, with 2855 individuals now living back in the wild; while another 5681 individuals inhabit the DFNNR, and 186 reside in BMP. Wild Milu, however, still face significant conservation challenges. The population lacks genetic diversity, leading to severe inbreeding depression and carrying multiple risks, such as high miscarriage rates, a reduced lifespan, and susceptibility to disease. Environmental constraints such as pollution and habitat fragmentation further result in small, fragmented wild populations. Moreover, the species currently lacks a national level conservation master plan, the associated coordinated monitoring platforms, and breeding plans for China’s captive populations. Finally, there is now a lack of international cooperation in the conservation of this species. We therefore call for both a national-level conservation master plan in China and international cooperation to develop a shared database and germplasm databank covering Milu across all countries with ex-situ populations, as crucial steps for securing the long-term conservation of Milu and preventing it from ever becoming “extinct in the wild” again.

As a new type of heritage, Agricultural Heritage Systems (AHS), represented by Globally Important Agricultural Heritage Systems (GIAHS) designated by Food and Agriculture Organization of the United Nations (FAO) and Nationally Important Agricultural Heritage Systems (NIAHS) designated by some countries’ Ministry of Agriculture, are typical Social-Ecological Systems (SES), which usually are rich in biodiversity, traditional knowledge, resource utilization technology and outstanding cultural landscapes. Cultural Keystone Species (CKS) are defined as the culturally salient species that shape the cultural identity of a people in a major way. CKS can be used as a prominent tool for the synergistic conservation of SES biology and culture, and to promote the overall enhancement of system functions. This paper summarizes a review of the definition of the CKS and its application in SES conservation. According to the characteristics and protection needs of AHS, this paper defined the CKS in AHS as: “Composites of biological resources and cultural practices, which have a significant impact on the stability of local society and culture systems, contribute to the achievement of AHS’ conservation goals.” Based on this definition, we analyzed the significance of the identification of CKS in AHS. First of all, CKS help to quickly identify the key elements of AHS. Secondly, CKS can promote community participation in the conservation and development of AHS. In addition, the identification of CKS has a significant role in food and livelihood security, biodiversity conservation, traditional knowledge and technology transmission, social organization maintenance, and cultural landscape maintenance in AHS, which helps to achieve the conservation goals of GIAHS and/or NIAHS.

Invasive species and habitat degradation are the main reasons for freshwater biodiversity loss. Reports on the habitat degradation and invasion ecology of Red Swamp crayfish (Procambarus clarkii) are few, although it is one of the most devastating invasive species in freshwater ecosystems. Based on a three-year investigation during 2017-2019 in West Dongting Lake, this study used Principal Component Analysis (PCA), Generalized Linear Model (GLM) and Bayesian model to analyze the relationships of P. clarkii stocks and environment factors in natural and modified wetlands. The results showed that the abundance of P. clarkii was positively correlated with total nitrogen, total phosphorus, water temperature, pH, water depth, and water transparency; while it was negatively correlated with dissolved oxygen and redox potential. The difference between P. clarkii stocks in natural and modified wetlands was nonsignificant. The P. clarkii stock decreased yearly, as levels in both 2018 and 2019 were significantly lower than in 2017. We concluded that inter-annual variation of the hydrological regime plays an important role in P. clarkii dynamics, and thus it is of great importance to ensure that the water level and flow velocity in summer to control the invasive P. clarkii.