\begin{tikzpicture} [scale=0.4,baseline,
  cell/.style={minimum size=0.35cm}]
\fill (0.65,0.65) rectangle (8.35,8.35);
\foreach \p/\c in%
{{(1,8)/forest},{(2,8)/forest},{(3,8)/forest},{(4,8)/forest},{(5,8)/forest},{(6,8)/forest},{(7,8)/white},{(8,8)/white}%
,{(1,7)/forest},{(2,7)/fire},{(3,7)/fire},{(4,7)/fire},{(5,7)/fire},{(6,7)/forest},{(7,7)/white},{(8,7)/white}%
,{(1,6)/forest},{(2,6)/fire},{(3,6)/white},{(4,6)/white},{(5,6)/fire},{(6,6)/forest},{(7,6)/white},{(8,6)/white}%
,{(1,5)/forest},{(2,5)/fire},{(3,5)/fire},{(4,5)/white},{(5,5)/fire},{(6,5)/forest},{(7,5)/white},{(8,5)/white}%
,{(1,4)/forest},{(2,4)/forest},{(3,4)/fire},{(4,4)/fire},{(5,4)/fire},{(6,4)/forest},{(7,4)/forest},{(8,4)/forest}%
,{(1,3)/white},{(2,3)/forest},{(3,3)/forest},{(4,3)/forest},{(5,3)/forest},{(6,3)/forest},{(7,3)/fire},{(8,3)/fire}%
,{(1,2)/white},{(2,2)/white},{(3,2)/white},{(4,2)/white},{(5,2)/white},{(6,2)/forest},{(7,2)/fire},{(8,2)/white}%
,{(1,1)/white},{(2,1)/white},{(3,1)/white},{(4,1)/white},{(5,1)/white},{(6,1)/forest},{(7,1)/fire},{(8,1)/white}}
\node[cell,fill=\c,draw=white,line width=1pt] at \p {};

\node[anchor=base] at (9,3.95) {\Huge$+$};
\begin{scope}[xshift=9cm]
\fill (0.65,0.65) rectangle (8.35,8.35);
\foreach \p/\c in%
{{(1,8)/white},{(2,8)/white},{(3,8)/white},{(4,8)/white},{(5,8)/white},{(6,8)/white},{(7,8)/forest},{(8,8)/forest}%
,{(1,7)/white},{(2,7)/white},{(3,7)/white},{(4,7)/white},{(5,7)/white},{(6,7)/white},{(7,7)/forest},{(8,7)/forest}%
,{(1,6)/white},{(2,6)/white},{(3,6)/ashes},{(4,6)/ashes},{(5,6)/white},{(6,6)/white},{(7,6)/forest},{(8,6)/forest}%
,{(1,5)/white},{(2,5)/white},{(3,5)/white},{(4,5)/ashes},{(5,5)/white},{(6,5)/white},{(7,5)/forest},{(8,5)/forest}%
,{(1,4)/white},{(2,4)/white},{(3,4)/white},{(4,4)/white},{(5,4)/white},{(6,4)/white},{(7,4)/forest},{(8,4)/forest}%
,{(1,3)/forest},{(2,3)/white},{(3,3)/white},{(4,3)/white},{(5,3)/white},{(6,3)/white},{(7,3)/white},{(8,3)/white}%
,{(1,2)/forest},{(2,2)/forest},{(3,2)/forest},{(4,2)/forest},{(5,2)/forest},{(6,2)/white},{(7,2)/white},{(8,2)/ashes}%
,{(1,1)/forest},{(2,1)/forest},{(3,1)/forest},{(4,1)/forest},{(5,1)/forest},{(6,1)/white},{(7,1)/white},{(8,1)/ashes}}
\node[cell,fill=\c,draw=white,line width=1pt] at \p {};
\end{scope}

\node[anchor=base] at (18,3.95) {\Huge$=$};
\begin{scope}[xshift=18cm]
\fill (0.65,0.65) rectangle (8.35,8.35);
\foreach \p/\c in%
{{(1,8)/forest},{(2,8)/forest},{(3,8)/forest},{(4,8)/forest},{(5,8)/forest},{(6,8)/forest},{(7,8)/forest},{(8,8)/forest}%
,{(1,7)/forest},{(2,7)/fire},{(3,7)/fire},{(4,7)/fire},{(5,7)/fire},{(6,7)/forest},{(7,7)/forest},{(8,7)/forest}%
,{(1,6)/forest},{(2,6)/fire},{(3,6)/ashes},{(4,6)/ashes},{(5,6)/fire},{(6,6)/forest},{(7,6)/forest},{(8,6)/forest}%
,{(1,5)/forest},{(2,5)/fire},{(3,5)/fire},{(4,5)/ashes},{(5,5)/fire},{(6,5)/forest},{(7,5)/forest},{(8,5)/forest}%
,{(1,4)/forest},{(2,4)/forest},{(3,4)/fire},{(4,4)/fire},{(5,4)/fire},{(6,4)/forest},{(7,4)/forest},{(8,4)/forest}%
,{(1,3)/forest},{(2,3)/forest},{(3,3)/forest},{(4,3)/forest},{(5,3)/forest},{(6,3)/forest},{(7,3)/fire},{(8,3)/fire}%
,{(1,2)/forest},{(2,2)/forest},{(3,2)/forest},{(4,2)/forest},{(5,2)/forest},{(6,2)/forest},{(7,2)/fire},{(8,2)/ashes}%
,{(1,1)/forest},{(2,1)/forest},{(3,1)/forest},{(4,1)/forest},{(5,1)/forest},{(6,1)/forest},{(7,1)/fire},{(8,1)/ashes}}
\node[cell,fill=\c,draw=white,line width=1pt] at \p {};
\end{scope}
\end{tikzpicture}