The research interest of our lab spans a broad range of topics, including island biogeography, conservation biology , community ecology, and urban ecology.
1. Island biogeography
Island biogeography theory has proven invaluable for developing and answering some of the most fundamental questions in ecology and evolution. We are interested in three general patterns: the small-island effect (SIE), nested subset pattern (nestedness) and island syndrome.
1.1 Small-island effect (SIE):
The SIE occurs when below a certain threshold area, species richness varies independently of island size or at least increases at a lesser rate than for larger islands. The SIE was first described about half a century ago (Niering 1963; MacArthur and Wilson 1967). However, it was only popularized after Lomolino and Weiser (2001) applied the breakpoint regression method for the first time to identify SIEs statistically. In addition, there are still serious debates over the appropriate methodology to identify the SIE. We are trying to gather datasets in the Thousand Island Lake and use global datasets to seek patterns and test hypotheses regarding SIEs. We found that amphibian and snake assemblages in the Thousand Island lake followed the SIE (Wang et al. 2015, 2017), while bird assemblages do not (Wang et al. 2012). We also demonstrates that empty islands play important roles in generating an SIE and that excluding empty islands is an important methodological shortcoming for the detection of SIEs (Wang et al. 2015, 2016).
1.2 Nested subset pattern (nestedness)
The nested subset pattern (nestedness) of faunal assemblages has been a major research focus in island biogeography and community ecology in recent decades. Nestedness occurs when species present at relatively depauperate locations constitute subsets of those present at more species rich locations (Patterson and Atmar 1986). We are trying to gather datasets in the Thousand Island Lake and Zhoushan Archipelago to seek patterns and test hypotheses regarding nestedness. We found that birds, reptiles and small mammals in the Thousand Island Lake all followed the nested subset pattern, but for different reasons (Wang et al. 2010, 2012). Butterfly assemblages in the Zhoushan Archipelago are significantly nested and selective extinction may be the main driver of nestedness (Xu et al. 2017). In addition, breeding birds and wintering birds in fragemented habitat islands (urban parks) are both significantly nested, but for different reasons (Wang et al. 2013).
1.3 Island syndrome
Adler and Levins (1994) coined the term “island syndrome” for a suit of correlated changes in traits of insular rodents. These mainly include shifts in life-history characteristics towards the slow end of the fast-slow continuum. Insular females will have larger offspring but will reproduce more slowly: they will start to breed at older ages, breeding less frequently and having smaller litters than females in mainland populations (Adler & Levins, 1994). Similar correlated trait shifts have since been found in other taxa, especially in birds and lizards, at both the population and species levels (Blondel, 2000; Covas, 2012; Pafilis et al., 2011; Novosolov & Meiri, 2013). Our study in the Zhoushan Archipelago provided the first case study in amphibians and showed that amphibians also follow the island syndrome (Wang et al. 2009; Li et al. 2011).
2. Conservation Biology
Extinction rates are increasing rapidly and recent extinction rates are estimated to be 100–1000 times those of pre-human times (Pimm et al. 1995). Accumulating evidence indicates that extinction risk is not randomly distributed among taxa. Identifying traits associated with increased extinction risk is an important prerequisite for the development of effective conservation strategies to minimize future biodiversity losses. We are trying to understand why species with particular traits are at greater risk of extinction than others. Our study in the Thousand Island Lake show that rare lizard species with low natural density are most vulnerable to fragmentation (Wang et al. 2009) and that bird species with low natural abundance and high habitat specificity are most vulnerable to local extinction (Wang et al. 2015). Our study on Chinese birds showed that the synergistic interaction between body size and hunting vulnerability was the single best correlate of their extinction risk (Wang et al. 2018).
3. Community assembly rules
A fundamental question in ecology is whether ecological communities are structured according to general assembly rules or are essentially dictated by random processes. Although many types of assembly rules have been described, few studies have tested multiple assembly rule models simultaneously. Therefore, little is known about the relative importance of potential underlying factors such as interspecific competition, inter-guild competition, selective extinction and habitat nestedness in structuring community composition. We are trying to understand of the mechanisms behind community assembly patterns and species coexistence. We found that bird assemblages in the Thousand Island Lake did not support predictions by several competitively structured assembly rule models, including Diamond’s assembly rules, constant body-size ratios, and favoured states. In contrast, bird assemblages were highly significantly nested and were apparently shaped by extinction processes mediated through area effects and habitat nestedness (Wang et al. 2011).
4. Urban ecology
Urbanization is one of the most extreme forms of land-use alteration occurring at an accelerating rate worldwide. Although urbanization often adversely affects and even causes extinction of native species, more and more bird species worldwide are colonizing and adapting to urban environments. However, the factors limiting the colonization of cities by most bird species from rural areas remain poorly understood. We are trying to understand the processes and mechanisms underlying species adaptation to urbanization. We found that Black-billed Magpies (Pica pica) can adjust nest characteristics (Wang et al. 2008) and Chinese Bulbuls (Pycnonotus sinensis) can adjust the composition of their nests to adapt to urbanization in Hangzhou, China (Wang et al. 2009). In addition, the common blackbird (Turdus merula) can use anthropogenic structures as nesting sites in response to urbanization (Wang et al. 2015).
1. Island biogeography
Island biogeography theory has proven invaluable for developing and answering some of the most fundamental questions in ecology and evolution. We are interested in three general patterns: the small-island effect (SIE), nested subset pattern (nestedness) and island syndrome.
1.1 Small-island effect (SIE):
The SIE occurs when below a certain threshold area, species richness varies independently of island size or at least increases at a lesser rate than for larger islands. The SIE was first described about half a century ago (Niering 1963; MacArthur and Wilson 1967). However, it was only popularized after Lomolino and Weiser (2001) applied the breakpoint regression method for the first time to identify SIEs statistically. In addition, there are still serious debates over the appropriate methodology to identify the SIE. We are trying to gather datasets in the Thousand Island Lake and use global datasets to seek patterns and test hypotheses regarding SIEs. We found that amphibian and snake assemblages in the Thousand Island lake followed the SIE (Wang et al. 2015, 2017), while bird assemblages do not (Wang et al. 2012). We also demonstrates that empty islands play important roles in generating an SIE and that excluding empty islands is an important methodological shortcoming for the detection of SIEs (Wang et al. 2015, 2016).
1.2 Nested subset pattern (nestedness)
The nested subset pattern (nestedness) of faunal assemblages has been a major research focus in island biogeography and community ecology in recent decades. Nestedness occurs when species present at relatively depauperate locations constitute subsets of those present at more species rich locations (Patterson and Atmar 1986). We are trying to gather datasets in the Thousand Island Lake and Zhoushan Archipelago to seek patterns and test hypotheses regarding nestedness. We found that birds, reptiles and small mammals in the Thousand Island Lake all followed the nested subset pattern, but for different reasons (Wang et al. 2010, 2012). Butterfly assemblages in the Zhoushan Archipelago are significantly nested and selective extinction may be the main driver of nestedness (Xu et al. 2017). In addition, breeding birds and wintering birds in fragemented habitat islands (urban parks) are both significantly nested, but for different reasons (Wang et al. 2013).
1.3 Island syndrome
Adler and Levins (1994) coined the term “island syndrome” for a suit of correlated changes in traits of insular rodents. These mainly include shifts in life-history characteristics towards the slow end of the fast-slow continuum. Insular females will have larger offspring but will reproduce more slowly: they will start to breed at older ages, breeding less frequently and having smaller litters than females in mainland populations (Adler & Levins, 1994). Similar correlated trait shifts have since been found in other taxa, especially in birds and lizards, at both the population and species levels (Blondel, 2000; Covas, 2012; Pafilis et al., 2011; Novosolov & Meiri, 2013). Our study in the Zhoushan Archipelago provided the first case study in amphibians and showed that amphibians also follow the island syndrome (Wang et al. 2009; Li et al. 2011).
2. Conservation Biology
Extinction rates are increasing rapidly and recent extinction rates are estimated to be 100–1000 times those of pre-human times (Pimm et al. 1995). Accumulating evidence indicates that extinction risk is not randomly distributed among taxa. Identifying traits associated with increased extinction risk is an important prerequisite for the development of effective conservation strategies to minimize future biodiversity losses. We are trying to understand why species with particular traits are at greater risk of extinction than others. Our study in the Thousand Island Lake show that rare lizard species with low natural density are most vulnerable to fragmentation (Wang et al. 2009) and that bird species with low natural abundance and high habitat specificity are most vulnerable to local extinction (Wang et al. 2015). Our study on Chinese birds showed that the synergistic interaction between body size and hunting vulnerability was the single best correlate of their extinction risk (Wang et al. 2018).
3. Community assembly rules
A fundamental question in ecology is whether ecological communities are structured according to general assembly rules or are essentially dictated by random processes. Although many types of assembly rules have been described, few studies have tested multiple assembly rule models simultaneously. Therefore, little is known about the relative importance of potential underlying factors such as interspecific competition, inter-guild competition, selective extinction and habitat nestedness in structuring community composition. We are trying to understand of the mechanisms behind community assembly patterns and species coexistence. We found that bird assemblages in the Thousand Island Lake did not support predictions by several competitively structured assembly rule models, including Diamond’s assembly rules, constant body-size ratios, and favoured states. In contrast, bird assemblages were highly significantly nested and were apparently shaped by extinction processes mediated through area effects and habitat nestedness (Wang et al. 2011).
4. Urban ecology
Urbanization is one of the most extreme forms of land-use alteration occurring at an accelerating rate worldwide. Although urbanization often adversely affects and even causes extinction of native species, more and more bird species worldwide are colonizing and adapting to urban environments. However, the factors limiting the colonization of cities by most bird species from rural areas remain poorly understood. We are trying to understand the processes and mechanisms underlying species adaptation to urbanization. We found that Black-billed Magpies (Pica pica) can adjust nest characteristics (Wang et al. 2008) and Chinese Bulbuls (Pycnonotus sinensis) can adjust the composition of their nests to adapt to urbanization in Hangzhou, China (Wang et al. 2009). In addition, the common blackbird (Turdus merula) can use anthropogenic structures as nesting sites in response to urbanization (Wang et al. 2015).