N addition on plant growth and community diversity. Finally, we will summarize and
look at general future research needs and directions in deserts from China.
11.2 Overview of Nitrogen Enrichment Experiments in
China’s Desert Ecosystems
The effects of N increase on desert ecosystems in China were focused in the
Gurbantunggut Desert of Xinjiang Province, the Tengger Desert of Ningxia Province, and the desert steppe of Inner Mongolia Province. There were also some
experiment sites from the Mu Us Desert of Ningxia Province, Horqin Sandy Land,
and Kubuqi Desert of Inner Mongolia Province. In the Gurbantunggut Desert,
studying plots were conducted in three different sites. Two sites from the center of
the deserts were chosen to study the responses of herbaceous plants, soil microbial
activity, and biocrusts to N addition (Zhang et al. 2016; Zhou et al. 2012, 2014). One
site from south of the desert was used to study responses of microbial community to
N addition and water changes (Huang et al. 2015a, 2018; Su et al. 2016) and also the
soil respiration affected by N addition (Yue et al. 2018). In the Tengger Desert, Su
et al. (2012, 2013, 2014) focused on responses of the community structure of
herbaceous plants to N addition or other fertilization in different years (Su et al.
2013a, 2014a, b). To evaluate desert steppe ecosystems under N deposition, many
plots were constructed in long-term experimental station for the grassland ecosystem
in Siziwang Banner, midwest of Inner Mongolia. The combined effects of N
addition, water, and temperature manipulation on soil physiochemical characteristics, ecosystem carbon exchange, and plant community structure were studied in this
area (Guo 2016; Li et al. 2018; Bai et al. 2013; Li 2014; Wang 2012; Yang 2012;
Zhang 2014). The N rates applied on the desert soil mostly ranged from 0 to 240 kg
N ha
À1 year
À1 (Su et al. 2013a; Zhou et al. 2012); some experiments even reached
800 kg N ha
À1 year
À1 (Huang and Yu 2016). The N form NH 4 NO 3 was used in most
of the N addition experiments, and urea was also applied in some sites. Most results
are based on the data collected from the fields, with small parts from pot experiments
(Zhou et al. 2011a).
11.3 Impacts on Nutrient Cycling
11.3.1 Physicochemical Characteristics
In desert ecosystems from China, soil total nitrogen (N) was generally increased by
the N addition (Huang and Yu 2016; Su et al. 2014a), while non-effects were also
observed (Zhang 2014; Zhou et al. 2012). Nitrogen addition usually increased the
available N concentrations (Su et al. 2014a; Zhou et al. 2012). Some other nutrients,
11 Impacts of Nitrogen Deposition on China’s Desert Ecosystems
247
look at general future research needs and directions in deserts from China.
11.2 Overview of Nitrogen Enrichment Experiments in
China’s Desert Ecosystems
The effects of N increase on desert ecosystems in China were focused in the
Gurbantunggut Desert of Xinjiang Province, the Tengger Desert of Ningxia Province, and the desert steppe of Inner Mongolia Province. There were also some
experiment sites from the Mu Us Desert of Ningxia Province, Horqin Sandy Land,
and Kubuqi Desert of Inner Mongolia Province. In the Gurbantunggut Desert,
studying plots were conducted in three different sites. Two sites from the center of
the deserts were chosen to study the responses of herbaceous plants, soil microbial
activity, and biocrusts to N addition (Zhang et al. 2016; Zhou et al. 2012, 2014). One
site from south of the desert was used to study responses of microbial community to
N addition and water changes (Huang et al. 2015a, 2018; Su et al. 2016) and also the
soil respiration affected by N addition (Yue et al. 2018). In the Tengger Desert, Su
et al. (2012, 2013, 2014) focused on responses of the community structure of
herbaceous plants to N addition or other fertilization in different years (Su et al.
2013a, 2014a, b). To evaluate desert steppe ecosystems under N deposition, many
plots were constructed in long-term experimental station for the grassland ecosystem
in Siziwang Banner, midwest of Inner Mongolia. The combined effects of N
addition, water, and temperature manipulation on soil physiochemical characteristics, ecosystem carbon exchange, and plant community structure were studied in this
area (Guo 2016; Li et al. 2018; Bai et al. 2013; Li 2014; Wang 2012; Yang 2012;
Zhang 2014). The N rates applied on the desert soil mostly ranged from 0 to 240 kg
N ha
À1 year
À1 (Su et al. 2013a; Zhou et al. 2012); some experiments even reached
800 kg N ha
À1 year
À1 (Huang and Yu 2016). The N form NH 4 NO 3 was used in most
of the N addition experiments, and urea was also applied in some sites. Most results
are based on the data collected from the fields, with small parts from pot experiments
(Zhou et al. 2011a).
11.3 Impacts on Nutrient Cycling
11.3.1 Physicochemical Characteristics
In desert ecosystems from China, soil total nitrogen (N) was generally increased by
the N addition (Huang and Yu 2016; Su et al. 2014a), while non-effects were also
observed (Zhang 2014; Zhou et al. 2012). Nitrogen addition usually increased the
available N concentrations (Su et al. 2014a; Zhou et al. 2012). Some other nutrients,
11 Impacts of Nitrogen Deposition on China’s Desert Ecosystems
247