A study led by young researcher Nawal Shrestha of Institute of Innovation Ecology , Lanzhou University was published in Biological Conservation recently

2021-08-02 14:54

A study led by young researcher Nawal Shrestha of Institute of Innovation Ecology and State Key Laboratory of Grassland Agro-Ecosystem, Lanzhou University entitled “Assessing conservation priorities of endemic seed plants in the central Himalaya (Nepal): A complementarity and phylogenetic diversity approach” was published in Biological Conservation recently. Nawal Shrestha is the first author and the corresponding author of the paper.

Protected areas (PA) are usually designed by taking into consideration the distribution ranges of certain flagship species, particularly mammals and birds. Although plants play an essential ecological role, they are often neglected and are hardly taken as a proxy for conservation decision-making. Several studies have documented incongruences between the spatial diversity patterns of different taxonomic groups, which means that different taxa have different conservation priorities and hence, areas prioritized for one may not necessarily ensure sufficient protection to the other. Therefore, given a potential scenario of conservation bias against plants, existing PA networks may be largely insufficient in protecting them. This emphasizes the need to reevaluate the representation of plants in existing PA networks and identify potential gaps in their conservation.

Globally, there are many cases where PAs are established in sites that are either unimportant to biodiversity or have the lowest conservation need. For example, areas that are economically less promising for alternate land use are usually selected for PA establishment due to ease in acquiring such lands. Such PAs not only fail to capture biodiversity but also cause considerable misallocation of conservation resources. In order to achieve maximum conservation benefit, the prioritized areas must be fully representative of the extant biodiversity. Such maximal representation of biodiversity can be achieved by systematically identifying sites of high conservation importance and establishing PAs in thus prioritized sites.

Districts and physiographic regions of Nepal and the percentage of protected areas (PA) coverage in each physiographic region.

Sites of complementary (a) species richness, (b) weighted endemism, (c) phylogenetic diversity and (d) phylogenetic endemism of endemic seed plants in Nepal identified by complementarity algorithm.

In the current study, the authors built one of the most comprehensive distribution datasets for the entire endemic seed plants (316 species) in the central Himalaya (Nepal) at a much finer spatial resolution (10 × 10 km2) to bridge the existing knowledge gap on the status of plant protection. Using this dataset and the largest time-calibrated phylogeny of global seed plants, they identified key areas for the systematic protection of species and evolutionary diversity of endemic seed plants in Nepal. Their assessment identified a total of 47 grid cells as priority sites for conserving overall species and evolutionary diversity of endemic seed plants. Interestingly, more than half of these priority grid cells (26 grid cells) were outside the existing protected area network, which shows a weak protection status of endemic seed plants in Nepal. Furthermore, they found that the mean range size of species in unprotected grid cells was significantly lower (F (1, 342) = 30.99; p < 0.001) than that of the species in protected grid cells.

Priority areas for systematic conservation of species and evolutionary diversity of endemic seed plants in Nepal and the gaps in conservation. Sites within and outside the protected area networks are shown in blue and red color, respectively.

Unlike the commonly used hotspot approach, which puts more emphasis to species-rich areas, the priority areas identified in this study are not only species diversity hotspots but also species diversity coldspots. While preserving hotspots would undoubtedly protect a large fraction of biodiversity, the biodiversity coldspots may be ecologically and evolutionarily important areas offering important ecosystem services and/or sheltering unique evolutionary lineages. Therefore, such areas should not be overlooked in conservation planning. Although Nepal's PA coverage is much higher than the Aichi biodiversity target, the existing PA network in Nepal is far from being ecologically representative. This study reinforces that simply increasing the land area for protection is less meaningful to overall biodiversity conservation. Therefore, instead of focusing on increasing the percentage coverage, countries should first evaluate if the prioritized areas are truly representative of the extant biodiversity. The findings of the present study have clear conservation implications for protecting endemic seed plants in Nepal and may be used as a baseline data to identify important plant areas in Nepal. This might also be useful in selecting representative areas for expanding PA networks in Nepal to meet the post-2020 global biodiversity target.

This work was supported by the Fundamental Research Funds for the Central Universities of China (#LZUJBKY202035).

Link: https://doi.org/10.1016/j.biocon.2021.109274